Ok so im at carshows meeting people or surfing the forums, they have turbos, and they all tell me they are running like 20+ lbs of boost. And some of these people have little 4 bangers, stock for the most part. And I ask how can they run 20lbs? It's still boost, it's measured the same way as roots. How can they do it. They tell me, turbo boost is way different than blower boost. HOW? ITS STILL BOOST MEASURED IN PSI
I have a blown BBC, flat top blower 8.5:1 pistons, @3-5lbs on pump gas. If I put much more boost on my engine I'd either have to run race fuel or change the pistons again.
So again, how are the two different in the terms that they can run 20+psi on a pretty much stock motor?
Thanks alot
I know water alcohol injection helps alot with detonation... Eroq on here knows a bit about them
I've always wondered the same thing....Im running 6psi on my blower and run 110 octane.... It will run with 91, but she dont like that loll ...... I know with vortech superchargers they run a pretty high boost level, like turbos, but vortec superchargers don't have to much effect in low rpms, unlike a turbo that you can spool up. Another thing I know is that roots blowers are direct drive from the engine, so I'm thinking this might have something to do with it???
Quote from: xjs3667 on July 15, 2012, 04:56:31 PM
I've always wondered the same thing....Im running 6psi on my blower and run 110 octane.... It will run with 91, but she dont like that loll ...... I know with vortech superchargers they run a pretty high boost level, like turbos, but vortec superchargers don't have to much effect in low rpms, unlike a turbo that you can spool up. Another thing I know is that roots blowers are direct drive from the engine, so I'm thinking this might have something to do with it???
I run 93 octane no prob.
a roots style blower is a "pump" there is no pressure within the case. All the pressure is in the manifold. There are two other kinds of superchargers, a screw charger, wich is where the rotors look pretty much like corck screws or wood screws if u will. all the pressure is built in the case. The centrifugal super charger or the "vortec charger" are both the same. It works like a turbo, except is driven from the serpent belt. And the pressure is made within the case. That's the difference between turbos and supers. Supers are all belt driven and have a parasitic effect on the motor. Bt in bothe the screw and centrifugal, they create a ton of boost, but not that much power from off idle or low rpm power like a roots. A 671 pushes like 640" of air in 1 rotation. But all I have to do to make more boost it change my pulleys and overdrive it, or get a bigger blower.
But I still want to know how these ricers are getting away with it.
Quote from: J.C. on July 15, 2012, 03:30:54 PM
I know water alcohol injection helps alot with detonation... Eroq on here knows a bit about them
My old man runs alcohol injected on his drag boat. He likes it so much more than gas, no detonation. He's got a billet 16-71 on there and it's overdriven a ton, idk what kind of boost is on it. But it runs like 2000+ hp
But that's the difference between gas and alky- no detonation you can run an engine to it's limits with the comp ratio and boost.
I remember when I was a kid I had one of them nitro rc trucks
one day I come home from school all pumped to play with it. All my nitro was gone. I asked dad what happened to it.
Dad -"oh yea bout that, I was running low on f-"
Me-"enough said." disappointment.
higher boost, requires higher octane to eliminate detonation. 20+lbs your looking at some expensive fuel!
Super chargers are great because they provide boost nearly right off the line, but do require horsepower to run...
turbos are great too because they use "wasted" energy... exhaust flow, and HEAT! you want the exhaust hot before the turbo and cold after the turbo... the temp drop results in more flow... compressor turbine spins more.
its all really pretty easy.. if you are seriously considering BUILDING a system, buy a book and read it. word for word, every page. You will learn TONS. one book i bought was Maximum Boost - written by Corky Bell. Alot of it carries over from blowers to turbos. Diagrams with air flow rates. pressure drop charts, anything you would need.
Or you can buy a turbo setup... but i know we are all on a budget and cant afford a $5000 turbo kit!
Quote from: Eroq on July 18, 2012, 01:50:52 AM
higher boost, requires higher octane to eliminate detonation. 20+lbs your looking at some expensive fuel!
Super chargers are great because they provide boost nearly right off the line, but do require horsepower to run...
turbos are great too because they use "wasted" energy... exhaust flow, and HEAT! you want the exhaust hot before the turbo and cold after the turbo... the temp drop results in more flow... compressor turbine spins more.
its all really pretty easy.. if you are seriously considering BUILDING a system, buy a book and read it. word for word, every page. You will learn TONS. one book i bought was Maximum Boost - written by Corky Bell. Alot of it carries over from blowers to turbos. Diagrams with air flow rates. pressure drop charts, anything you would need.
Or you can buy a turbo setup... but i know we are all on a budget and cant afford a $5000 turbo kit!
I know how turbos work and how to rig em. But I was just currious about my question. I was doing some extra research, Somone said it's because its not the psi, it's the airflow.
But as far as superchargers go, I'm pretty good with em. I built a few and converted em from diesel to gas, I'm pretty good with their boost levels and air ratios. But I know if you added a chiller to a blower that's like an instant 100hp
I never thought there was a difference. 20psi is 20psi. But I see where you went wrong. They told you that's what they are running. Ask them for a dyno sheet and that should shut up 95% of them.
Quote from: ice87 on July 18, 2012, 09:36:18 AM
I never thought there was a difference. 20psi is 20psi.
That's what I thouht.
But what I was told is that some turbos are forcing small amounts of air into the engine @20psi. Not like a 671 where it's 640"s at 1 revolution.
So idk what to think
turbos spin alot faster then a roots, and have smaller area to compress the air ???
Quote from: J.C. on July 18, 2012, 04:17:01 PM
turbos spin alot faster then a roots, and have smaller area to compress the air ???
True. And roots aren't compressers. They are pumps. All the pressure is made in the manifold.
Quote from: Jthomas on July 18, 2012, 04:18:48 PM
Quote from: J.C. on July 18, 2012, 04:17:01 PM
turbos spin alot faster then a roots, and have smaller area to compress the air ???
True. And roots aren't compressers. They are pumps. All the pressure is made in the manifold.
there ya go!
Thats what I'm thinking, It takes more pressure for the turbo to put same amount of air in as a blower at lower psi,
My mistake. I think a 671 is 411"s per rotation.
I guess just the though irritates me. Like I spend twice the $$ in just engine parts, I have twice as Many cylinders, big cubes.
And I look at vids on YouTube of like a 1000HP Honda. And I'm just like. Wtf... Just by the looks, it's just a big ass turbo. Now I assume there are engine mods. But if that were on a built v8????
OK sorry but the 1000hp Honda's are not your everyday Honda. Lots of money into those builds. Look at the new ls/vortec motors. Change exhaust, valve springs and fuel system and you can run 600+ on a complete stock motor. I also think you could run more psi in your motor but need a nice ignition system so you can pull more timing out with the higher boost.
Your question got me thinking and I couldn't figure it out but the is the best I could find on the web.
PSI is half the equation, the other is flow, or CFM. Think of it like a pressure washer. You have one with 3000 psi (the pressure at the tip) and 2.5 gpm (how much water it flows out over a minute). The 2 work together to determine what you can clean. You could have 1,000,000 psi, but at .001 gpm, you aren't going to clean anything. So a turbo's efficiency will depend on how much boost pressure it can achieve, as well as the total volume of air it can move. 35 psi sounds like a lot, but is unimpressive if its only moving 50 cfm. Make sense? For best results, you want a properly sized blower. Too large a supercharger will create a flow restriction, costing hp. Too large a turbo will cause extreme lag. A large turbo is slowly building pressure (and power) but it still gets there. A garret T91 is too big for a 1.6L Civic, but if it eventually spun, it would make big power and a big explosion
Quote from: ice87 on July 20, 2012, 02:51:37 AM
Your question got me thinking and I couldn't figure it out but the is the best I could find on the web.
PSI is half the equation, the other is flow, or CFM. Think of it like a pressure washer. You have one with 3000 psi (the pressure at the tip) and 2.5 gpm (how much water it flows out over a minute). The 2 work together to determine what you can clean. You could have 1,000,000 psi, but at .001 gpm, you aren't going to clean anything. So a turbo's efficiency will depend on how much boost pressure it can achieve, as well as the total volume of air it can move. 35 psi sounds like a lot, but is unimpressive if its only moving 50 cfm. Make sense? For best results, you want a properly sized blower. Too large a supercharger will create a flow restriction, costing hp. Too large a turbo will cause extreme lag. A large turbo is slowly building pressure (and power) but it still gets there. A garret T91 is too big for a 1.6L Civic, but if it eventually spun, it would make big power and a big explosion
Okay I think I'm getting all this. But they still make power? But again they are always poping head gaskets. the ricer is a whole other breed of car enthusiast.
If I were ever to get a 4 cylinder it would be the old school vega.
But as far as my ignition, I don't want to spoil any surprises for the build. But it's good. Trust me loll
I got really nice flowing heads, and everything i have will work great with one another.
Well I did alot of researching about putting a Turbo on my bike and alot of tuners don't pull enough timing when they up boost. So it goes off before it should messing up pistons and heads.
http://www.hondatuningmagazine.com/tech/htup_0805_500hp_stock_block_b16a/viewall.html (http://www.hondatuningmagazine.com/tech/htup_0805_500hp_stock_block_b16a/viewall.html)
Found this article: 505hp 340lbs Honda 1.6 but it spins to 8,000 and has to be running 24psi. To me that's not that great. Alot of money for not alot of power.
After reading a few articles about the differences and similarities I still can not find a definitive answer, but have come to conclude a few things that we all forgot to mention.... and it involves simple science....
A turbo and vortec supercharger are almost always hooked up to an inter-cooler.
What does it do exactly? it takes the "exhaust" air from the turbo, etc. and cools down to be more efficient in the combustion process.
I have only very rarely seen a roots style blower hooked up to an inter-cooler unless running very low psi, which then itd really just for show. some are that are mounted directly to the manifold have cooling jackets, for the antifreeze to help cool the exhaust air on them. As we all know what our normal coolant temp. is 180-200 est. I would say it is not the best method to cool it.
Also I know for a fact that on the blower I have the exhaust temps are right around 250-300 degrees, exceeds 300 degrees in full boost, this is only at 6psi !!
Now the simple science part..... you have to take a loook at the thermodynamic cycle of an engine, basically the cooler the intake air the more efficient the expansion rate in the combustion cycle.
Cold air is denser than hot air, the molecules are closer together, and hot air the molecules are further apart or expanded.
hopefully you can see the point Im trying to make by now,
If not, well.... what air takes up more "space" air at 300 degrees or air that has gone thru an inter-cooler and is now 120 degrees.
Thus making a turbo at idk 15psi, putting the same amount of air in as a roots style supercharger at 6psi, ( this is an example guys) I'm sure theres some formula out there.
Now with a roots blower there are things done that can help cool the exhaust air of the blower before it is combusted, perfect example is top fuel drags, they run on pure alcohol, which absorbs the heat of the incoming air and cools it down before combustion. Another thing some people so is run meth injection/ alcohol injection, this not only raises the detonation point, helps in the cooling process of the air.
I gotta say I might be way off on all this, but it is really the only explanation I can come up with, Simply it is a higher boost level from a turbo because its exhaust temps. are lower than a blower. thus it is still putting the same amount of air into the engine
this is why there is such a huge argument over which is more efficient, I am not going to get into that loll as I am a blower guy :)
And yes I came up with all this on my own :)
Roots blowers can't be inter cooled. Unless you use a chiller. Chillers and intercoolers do the same thing. They cool the boost giving you a denser air intake charge wich creates more power
I know all the science behind all forced air induction. But back to top of page one. How the F can it happen?
Lower compression - > higher boost ==np
Lil ricer motors have a short stroke and low compression. = high rpms and lots of boost
Turbos are more efficient yes. But you can't create as much power with one as roots. If not, then why do all the top fastest cars use them???
Blowers are way better. I don't care if it takes a few hp to spin one. But the outcome is better. An roots are all positive displacement. Everything that it sucks in, go out.
I think they do create as much power, one is off idle(blower), one is after it spools(turbo). Maybe that is why it seems to be different, when really its the same, just at a different time ???
Yes Blowers can be inter-cooled.... When the funds are available to me I am going to be buying a inter-cooler for my blower!! I know all the science behind forced induction also, It helps a lot to know about in every detail if you want a proper setup.
Please explain to me why you think an inter-cooler can not be used on a roots style blower??
And yes the lower the compression ratio the higher boost levels you can run but to a point.... My compression ratio stock is 8.5:1 and by running 6psi it brings it to 12.1:1 you never want to exceed 14.5:1 but I keep mine around 12:1 so I can stay on pump gas but ideally I should be running 100+ octane but she is fine on 98.....
Quote from: Jthomas on July 20, 2012, 04:10:26 PM
I know all the science behind all forced air induction. But back to top of page one. How the F can it happen?
as I said before, the air out of a roots blower is hotter, therefore expanded already and has less room to expand more, air out of a turbo is cooler and less dense and has more room to expand when combustion occurs.
Also when it comes to force induction, remember you will always be limited by how much air you can force into the cylinder, be it from valves to restricted exhaust,
I've never dealt with turbos and I am limited to the knowledge on if the boost gauge is pertinent to the system, but it is not for a roots blower If system is correctly set up.
boost gauge= useless piece of equipment just to look at loll..... if your system is properly setup your gauge will read little to boost untill the higher rpms, and the air starts to build up in the manifold due to the limitations of your engine. your engine no matter what it is can only be efficient with X amount of air, once that limitation is reached there is no way to limit the blower to it since it is direct drive off the rotating assembly of the engine, and excess air is pumped into the manifold there fore giving an artificial boost reading.
Even though a roots style blower is not a compressor, its simply an air pump, there is no need for it be a compressor, as the air that exits the blower is hot and expanded (taking up more space) so kind of compressed in a way. there is no lag in a blower, there is constant output, this is why they have bypass valves, for closed throttle/idle, otherwise the engine will rev up at closed throttle since it is constantly trying to make the engine run at 100% efficiency, the more air you put in the more fuel used= faster rpm=turning the blower faster=runaway engine= not good!! loll
Turbos by using exhaust gases are more efficient in this manner as it does not rob the engine of the same amount of power as a blower. There is Lag. It is designed to compress air and cool it down then into the engine, If a turbo were to try and compress hot air it wouldn't work, air can only be compressed so far when hot and when compressing cold air the compression process heats the air and it expands. So by using cold air the turbo can spool and compress the air, the air gets hot in the compression process and is then cooled back down and used by the engine, then it takes more time for the cooler air and more volume of air to equal the same amount of the hot air produced by the blower.
both turbos and blowers have there ups and downs, and efficient in one way but lack in another.
If you still don't follow me with the hot air cold air thing, I came up with a perfect example anyone can try at home while I was typing all this loll
Get a balloon and blow it up, Think of the balloon as your engine.... You obviously don't want to force too much air into it or it will pop and break. Like wise you don't want to put not enough air into the balloon that it is not holding the full volume of air that it can.(100% efficiency)
*Note* while blowing up the balloon, your kids or wife might think you are planning a party of some sort... notify them there is no such party in the making and it is a simple experiment and you might give them the balloon when done. :)
Ok take your now blown up balloon and place it in the fridge or freezer, go drink a beer or 2 to occupy your time :) come back and check on the balloon, notice how it is quite smaller than when you placed it in there?? this is because the air contracted and the molecules squeezed closer together. Now let the balloon warm back up and notice how it gets bigger. Warm the air i the balloon even warmer and it gets even bigger until you reach the limits of the balloon and pop... you just broke something.
*note* you can now give you popped balloon to your child or wife or whoever and tell them I told I would give ya the balloon when I was done. loll
as you can see having the air hot before entering the cylinder means same amount of air as cold air to compress yet hotter air has more volume, therefore the cylinder doesn't need as much air to compress to achieve higher compression ratio!!
By using cold air the same amount is there just less volume, so it takes more air to achieve the higher compression ratio.
I am more familiar with blowers as that is what I run, and don't know this information off hand for the turbos.
but There are mathematical equations to determine what boost you are running, what compression ratio you will achieve and what horsepower and torque ratings that will be achieved. Also there are equations to know how much to overdrive or underdrive the blower, and what rpm the blower will be spinning at when the engine has reached max rpm.. you don't want to overspin your blower thats not good loll
If any one would like these equations let me know :) I'l post em here for ya. but they are only for roots style superchargers.
Finding the happy median where you will not damage your engine or your blower, yet have the blower be efficient in all rpm ranges is prudent to whether your engine will last or grenade, perform or fall flat on its face. Installing forced induction is a science and not just something that can be bolted on and go, sure it might work, but you will not be using all of the capabilities of the system that is right under your nose!! And who wouldn't wan't to get everything for there penny when it comes to HP :)
No I completly understand. But I think the "intercooler" you speak of, and a chiller are what we both are thinkin of. It sits on top of the manifold and under the blower and is water cooled. And as mentioned above that both turbos and roots will make the same power. Yes, true. But I want that off the line power. Instant boost. (roots)
And also I don't think you could get as much air in your engine as a 16-71 or 18-71, as you could with turbos, per 1 revolution.
Quote from: xjs3667 on July 20, 2012, 06:23:04 PM
but There are mathematical equations to determine what boost you are running, what compression ratio you will achieve and what horsepower and torque ratings that will be achieved. Also there are equations to know how much to overdrive or underdrive the blower, and what rpm the blower will be spinning at when the engine has reached max rpm.. you don't want to overspin your blower thats not good loll
If any one would like these equations let me know :) I'l post em here for ya. but they are only for roots style superchargers.
Finding the happy median where you will not damage your engine or your blower, yet have the blower be efficient in all rpm ranges is prudent to whether your engine will last or grenade, perform or fall flat on its face. Installing forced induction is a science and not just something that can be bolted on and go, sure it might work, but you will not be using all of the capabilities of the system that is right under your nose!! And who wouldn't wan't to get everything for there penny when it comes to HP :)
I also have the charts and books on all the math. I have a pretty Penney in just the engine part of my build. I have calculated every aspect of the engine, and have built it to proform for my application. I have a dead line by October for this truck to be driving. I'll post a build thread when it's done. I don't want to say anything to spoil the suprise.
cool Ill be waiting for pics!!! :) can't wait to see it...
The inter-cooler I am talking about is one for a turbo, I am going to modify it to work for me :) I know what your talking about.. the water cooled manifolds for the blowers that bolt to the manifold.
But for my instance I made my own blower kit for my jeep, there is only a couple of actual kits for the 4.0L but are like freakin 5-6k!!! yea... not for me.... so I fabed up my own using a eaton m90 off of a jaguar, these blowers are "remote mount" not directly bolted to the manifold, instead they have piping going to the manifold. And I fabbed a bracket to mount the blower where the ac compressor was.... And I figure if I got piping going from the blower to the manifold, then Why not try and stick a inter-cooler between the 2? I figure its worth a shot? I've never really heard it done before, but Ive never seen a blower mounted on a 4.0L like I did either and it works freakin great!!!
Its all trial and error, if the inter-cooler idea don't work... ohh well, it runs like a raped ape now with out it anyways loll if it does work, freakin sweet!! one more one off custom thing done, And when I fab something up or come up with some thing new its always about functionality first then looks :)
you are 100% right tho for instance my blower eaton m90 has a max rpm of around 18,000rpm a flow of 90 CID of air per revolution
where as a comparable turbo for the same engine sizes are, max rpm is around 150,000rpm!!! since turbos are different and dont make power untill spooled, normal operating range is around 100k-140k rpm. with a flow rate of almost nothing per revolution, in fact they measure a turbos flow rate with lbs. per min. and at 46k rpm the lbs. per minute is like 1.10lbs per min.. loll
so now we all can see why there is the lag that there is.
I personally prefer a blower and probably will never install a turbo on anything I own unless I hit the lotto big and just have money to throw around loll..... but until then I will stick to my beautiful whine of a blower and the instant power, and knowing that it is there soon as I put my foot into it a little. and there is lees stuff to go wrong with a blower, they are very reliable.
Jthomas, I am glad that there is some one out there with the same amount of knowledge as me when it comes to the subject, If you are anything like me, once I start leaning about something like this I can't stop until i know it all, which will never happen since people are always coming up with something new everyday :)
I know I went a little in detail a lot but not directed towards you or questioning your knowledge, :) I figured there isn't much out there and felt like being talkative loll so everyone else that doesn't know the subject can learn some.
Good luck to ya can't wait to see her when shes done.... my next project in the near future is guna be throwing a 6-71 on a 454 maybe a 572 I'll be building for my dad for a suburban he's restoring :)
Cool it with propane ;)
I figure the shorter stroke of the ricers enter into it because ya got less mass moving in shorter distance with just as strong of components.. Stays together a little better than a long stroke American truck/suv engine under boost.. ==dunno personally I prefer superchargers for off the line/low end boost...
Quote from: xjs3667 on July 20, 2012, 06:23:04 PM
as you can see having the air hot before entering the cylinder means same amount of air as cold air to compress yet hotter air has more volume, therefore the cylinder doesn't need as much air to compress to achieve higher compression ratio!!
By using cold air the same amount is there just less volume, so it takes more air to achieve the higher compression ratio.
ok but i will make more power with colder air. it is true will hotter air your compression would be higher than the same amount of cold air. but with cold air i can put more air into that cylinder and have the same volume but have more oxygen then you. more O2 means more fuel which = more hp
colder air is always better no matter what
Quote from: lilred on July 20, 2012, 10:00:25 PM
I figure the shorter stroke of the ricers enter into it because ya got less mass moving in shorter distance with just as strong of components.. Stays together a little better than a long stroke American truck/suv engine under boost.. ==dunno personally I prefer superchargers for off the line/low end boost...
If you changed the crank maybe. If he had shorter rods, it would have a faster stroke, but also built a lot on heat. I've always used the longest rods I could get away with.
But I was thinking about their low comp ratio and boost. Now I only have a roots chart to refer too, so I'm sure it's inaccurate when talking about turbos. But with 8.5:1 comp, on 5psi is something around 12:1-12.5:1? Off the top of my head? oh and assume this is all on pump gas.
So if these guys are running, say 15+ psi. Now there is now way they are keeping this on pump gas. But that's thinking in terms of a roots. But I'm still baffled.
Im going out on a limb here. They do run that much boost and Push huge hp out of these 4 cylinders....
BUT, the lifetime of these engines is less than a snowballs chance in hell???
Okay and one last thing. If they are running these crazy boost levels. Now even on the built up 4 bangers, how can they get the flow? Hp?
They have 1 head, 4 cylinders, we have double. How can they get the flow to Mach the cfm of the injecter and turbo ect? With one head. and simply, how can they create that much F ing power!?!? YouTube "Nissan from hell"
Go crazy with em.
Here's a good one.... Base is the 4afe (1.6l) same engine that was in my 93 geo prizm. 300hp @ 21psi
http://forum.9000rpm.co.za/viewtopic.php?id=6020 (http://forum.9000rpm.co.za/viewtopic.php?id=6020)
bore 81 mm, stroke 77 mm
So if these guys are running, say 15+ psi. Now there is now way they are keeping this on pump gas.
[/quote]
they are running on pump gas because all the boost is going through an intercooler. This cooler air can be run on pump gas.
Quote from: ice87 on July 21, 2012, 01:55:16 AM
So if these guys are running, say 15+ psi. Now there is now way they are keeping this on pump gas.
they are running on pump gas because all the boost is going through an intercooler. This cooler air can be run on pump gas.
[/quote]
x2 it is the hot air that causes detonation early, we have to run higher octane or meth injection or straight meth, as I said before to absorb the heat of the hot air not only does it higher octane burn more efficient,produce more hp but it cools the engine, and allows us to advance timing to a ungodly level....
now with the 4 bangers pushing that much hp, they are heavily modified, might look stock on outside but internals is where its all at, THERE IS NO WAY IN HELL a stock 4 banger can handle 1000hp!!!
also they are from what I know dual overhead cams, not only does it put less drag on the engine,( the cams directly open and close valves, compared to say a sbc lifters, pushrods, rockers, then valves) but they have 4 valves per cylinder compared to our 2.
yeah yeah yeah they might make 1000hp but you do know there are V8 making 2000+hp.... just remember hp cost $$$ and lots of it loll
I could just pour a couple gallons of meth in my tanks with pump gas?
And now that I go back and read. All of these big hp 4 cylinders are measured in RWHP!!
That's why they get big power readings, its not measured at the crank. Wimps.
You can build alot of hP and Tq just through your gearing and tranny. Non of the cars I've seen have been dynoed on an engine dyno. Just the tuner kind.
Oh and I don't really see much of engine discussions on here like this thread. These are the ones I like to see.
The only torque multiplier I know of in a drivetrain is the torque convertor in a automatic and that's minimal gain... Other than that, drivetrain robs power...
Quote from: Jthomas on July 21, 2012, 01:04:36 PM
I could just pour a couple gallons of meth in my tanks with pump gas?
And now that I go back and read. All of these big hp 4 cylinders are measured in RWHP!!
That's why they get big power readings, its not measured at the crank. Wimps.
You can build alot of hP and Tq just through your gearing and tranny. Non of the cars I've seen have been dynoed on an engine dyno. Just the tuner kind.
How?
gearing does multiply torque..... try taking off in 5th gear form a dead stop sometime tell me how that works out loll
and yes you can add methenol into the gas, but your going to want want to get the ratios right.
also I do agree with the dynos, there is such a variant between them, I mean its all on how they are set up or calibrated.... you could one place and your rwhp rating is say 300hp and go to another, and its reading 400hp.... wtf? I don't think they are accurate at all and really only trust an engine dyno, plus all the math equations are there to find out what your engine hp will be after add on's, well it gets really close to a point as it doesn't include like port and polish heads or what carb you are running
Quote from: Jthomas on July 21, 2012, 02:12:59 PM
How?
Friction..... Show me a set up that has more horsepower at the wheels than it does at the flywheel....
Dynos only measure torque, horsepower is a math equation :P
http://www.engineersedge.com/motors/rotating_horsepower_equation.htm (http://www.engineersedge.com/motors/rotating_horsepower_equation.htm)
lil red you are right, there is substantial loss in hp thru the drivetrain, but its "fixed" with the torque of the gearing. Every engine will produce more hp at the fly than wheels, but not the same torque.
and because every dyno is setup up differently the numbers will never match between the dyno places, and because the dyno's use torque to measure hp I could change my gearing a little or manually lock my torque converter and bata bing bata boom, I just changed not just tq but hp ratings as well. all dynos measure in torque even engine dynos. But if you use an engine dyno there is no gearing in the vehicle that can be changed to obstruct the actual tq/hp ratings. and By using the same engine dyno whenever changes are made you will have a consistent reading. Same applies with chassis dynos, use the same dyno always to have a consistent reading.
And if anyone still thinks gearing doesn't play a role..... why do you think they don't dyno it in 1st or 2nd gear?? because it would off the charts!!
I used to run a engine dyno.... that was a fun job :)
Just did some researching on dynos and as long as you go to a place that has a good dyno operator and its calibrated corrected then you don't get more HP or torque at the wheels. They plug in what gears you have and your tire height so you don't get off readings. One guy said in his mustang he changed gears and used the same dyno same operator and the difference was 1% between the 2.
They both have there place I would like a supercharger on my truck for more down low power but I want to put a Turbo on my bike for the high rpms it turns.look up the newhe 2013 mustang, its has 650hp on a supercharger that putting out somewhere between 12-15psi. But that is also running an intercooler for the higher boost.
Quote from: ice87 on July 22, 2012, 05:21:44 AM
Just did some researching on dynos and as long as you go to a place that has a good dyno operator and its calibrated corrected then you don't get more HP or torque at the wheels. They plug in what gears you have and your tire height so you don't get off readings. One guy said in his mustang he changed gears and used the same dyno same operator and the difference was 1% between the 2.
They both have there place I would like a supercharger on my truck for more down low power but I want to put a Turbo on my bike for the high rpms it turns.look up the newhe 2013 mustang, its has 650hp on a supercharger that putting out somewhere between 12-15psi. But that is also running an intercooler for the higher boost.
x2 as long as you have a good honest dyno operator then your good.... there are countless times people have asked me or said they will give me some extra $$ to punch in different numbers to give them a higher hp/tq ratings...wouldn't do it and never will... big fines and didn't wanna loose my job... but there are guys out there that will, so I am always a little skeptical when it comes to peoples claims even when they have the papers.... I go by the math and always will, I understand it will be off by a few ponies but when the math adds up to 300hp and they guy hands me a paper saying 420hp wtf?? If hes lying and cheating on one thing then you damn well he's doing it about other things in his engine...did he really build it up or just slap a cam and a dress up kit on it loll
Yup what alot of people don't realize is the engine dyno or chassis is only another tool. Its there to help you find what A/F and timing that motor and combo likes. You can build 2 exact motors with the same parts and each motor will like different timing and jets. Another thing is elevation and humidity can throw numbers off alot too.
Thinking out loud here. If they were to run that much boost, they have to drop the comp ratio (duh) but to run THAT MUCH, they would have to drop it alot, the wrist pin height would interfere with the rings, and actually make the rings weaker, leading to failure? Leading to engine damage/failure? Cuz I mean them suns of bitches are doing like 9k+rpm
Nope most are running around 8-8.5:1 running that much boost
if your going to shops where the dyno #s are wrong I wouldnt trust the work they do... and would be taking my psrts to someone else to do it... I had my old motor dynoed at 492 hp 355.. the guys that dynoed mine offered to make me a different slip saying 900 hp to mess with friends, and I almost did it but never did. and theres nothing wrong with that as long as your not selling the motor as the fake #. when I dyno my new 468 I am going to have a paper with a 1200 hp# on it for p00 's and giggles.
and a friend of mine ran a blower on his play truck never worked right and after 3 months his 383 was junk.
Quote from: betterbeaters on July 27, 2012, 12:09:20 PM
if your going to shops where the dyno #s are wrong I wouldnt trust the work they do... and would be taking my psrts to someone else to do it... I had my old motor dynoed at 492 hp 355.. the guys that dynoed mine offered to make me a different slip saying 900 hp to mess with friends, and I almost did it but never did. and theres nothing wrong with that as long as your not selling the motor as the fake #. when I dyno my new 468 I am going to have a paper with a 1200 hp# on it for p00 's and giggles.
and a friend of mine ran a blower on his play truck never worked right and after 3 months his 383 was junk.
When it comes to blowers, blowers are the tune up. You change one aspect of the blower, and you have to change your tuneup.
Quote from: betterbeaters on July 27, 2012, 12:09:20 PM
if your going to shops where the dyno #s are wrong I wouldnt trust the work they do... and would be taking my psrts to someone else to do it... I had my old motor dynoed at 492 hp 355.. the guys that dynoed mine offered to make me a different slip saying 900 hp to mess with friends, and I almost did it but never did. and theres nothing wrong with that as long as your not selling the motor as the fake #. when I dyno my new 468 I am going to have a paper with a 1200 hp# on it for p00 's and giggles.
and a friend of mine ran a blower on his play truck never worked right and after 3 months his 383 was junk.
and that right there is the reason why a dyno slip means nothing to me lol
I only wanted fake ones for a few people the rest see the real ones. I'm proud to have dyno papers and would only show the fakes to close friends that I want to mess with and when the last time you seen a 1200 hp 468 n/a with iron heads and pump gas? I want # so big you will know its bs for jokes but guess we play different games here lol also if you see dyno papers u can call the shop that did it and ask them to prove it! lol the guy that got my 355 did.
dude Im not putting you or your motor down in anyway... Im just saying that if anyone would even offer a different dyno sheet no matter how obscured the numbers are, it is not right and should not have a job. I would not trust anyone that runs that dyno and does that. jmho... and If it was my shop and I found guys doing that they would be gone in a heart beat, it is very hard to get a good rep. and the only word that will get out is that they change dyno numbers.. :)
Quote from: xjs3667 on July 28, 2012, 12:26:15 AM
dude Im not putting you or your motor down in anyway... Im just saying that if anyone would even offer a different dyno sheet no matter how obscured the numbers are, it is not right and should not have a job. I would not trust anyone that runs that dyno and does that. jmho... and If it was my shop and I found guys doing that they would be gone in a heart beat, it is very hard to get a good rep. and the only word that will get out is that they change dyno numbers.. :)
I guess I should have said the owner of the shop is the one who offered cause he is a friend of mine. he will not do that for anyone else! lol