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Yes in the sense that it's a sensor that reads it, but his argument was about having an aftermarket gauge you've installed in the interior that is wired to read the pressure above atmospheric pressure in the intake manifold.
As long as you accept that N/A vs N/A are given equal amounts of air, which is an entirely different thing than Turbo/Blower vs Turbo/Blower given equal boost. They are not equatable.
If you're tuning a turbo car for 500whp, you know exactly how much peak boost you're building to achieve that. Like I said, a boost gauge is just diagnosis tool and you can read it to see if you're building boost in a way you expect. It makes sense when you look at the boost of a specific, individual car because you know exactly what's been done to said car: you know how much displacement it has, what kind of turbo or blower it has on it (size, type, specs, etc.) and so on. Only in that context does using the boost gauge make sense, because it will be an expected variable to indicate how healthy the forced induction system is. What doesn't make sense is using an arbitrary boost value in an incomparable situation where you have two engines that have different displacements, different blowers/turbos, etc. The only equalizer is air shoved in there and whichever engine is more effective at using that air - that engine will be superior.
Well if you push the same amount of air through both holes, they're going to have equivalent flowing air of course (CFM measured will be equal). If one is flowing 200 CFM and the other is flowing 240 CFM naturally, then in order to get the 200 CFM to flow 240 CFM, you would need to apply more pressure to the hole. Now they're both flowing equal air, but now more pressure is being applied to the originally 200 CFM hole. Equal air, not equal pressure. So to answer your question, applying equal pressure will just continue to let the original 240 CFM hole always have more air.
A turbo can only flow as much air as a turbo can flow air. Let's say we put the same turbo on a 4.6L V8 and a 5.7L V8 and we have it spinning at max, constant RPM that the turbo was designed for. In this example, the turbo is trying to force the same amount of air into each engine. However, the 4.6L V8 will have more pressure built than the 5.7L V8. Now I ask, why would the boost gauge give any indication as to which engine is capable of flowing more air? The answer is, it doesn't, it's entirely subjective to the application!
The only true indicator is to put them on the dyno with everything as equal as possible: same fuel, same dyno, same day, have one very skilled tuner tune them both to the best of his ability, etc. Try to eliminate every possible variable outside of engine design/architecture itself. That's the only true test, which one can make more power give X amount of air.
I don't care about x amount of air. That is not fair to a engine that flows more. Push on them the same amount .....same efficiency and let the cfm fall where it may. Any other way is wrong and handucapping one engine vs the other no matter the make of engine.
We are on the same page here. I just want a test more comparable ......not a test to show me one engine makes the same power but at less boost. I already know that. I want to see the actual power difference.
Is there a formula for that. Last time your formula showed the ls made more power per cfm i think is how you had it. One should be able to figure how much more cfm x engine would flow with additional boost......or at different boost levels.
Originally Posted by zz4camaro1980
Isnt a MAF essentially a CFM gauge?
Do you have a guage on your maf??......i don't. But if i had a blower or turbo i would have a boost guage.
Yeah last time I figured out how much horsepower each engine made per CFM. Not hard to calculate, but I need to know these things: displacement, boost, and at what RPM the engines make peak power. Also what that peak power is.
If you can find that information about the Mach1 and LS1 cars you mentioned earlier, we can find out.
Yes in the sense that it's a sensor that reads it, but his argument was about having an aftermarket gauge you've installed in the interior that is wired to read the pressure above atmospheric pressure in the intake manifold.
Originally Posted by HioSSilver
I don't care about x amount of air. That is not fair to a engine that flows more. Push on them the same amount .....same efficiency and let the cfm fall where it may. Any other way is wrong and handucapping one engine vs the other no matter the make of engine.
We are on the same page here. I just want a test more comparable ......not a test to show me one engine makes the same power but at less boost. I already know that. I want to see the actual power difference.
Is there a formula for that. Last time your formula showed the ls made more power per cfm i think is how you had it. One should be able to figure how much more cfm x engine would flow with additional boost......or at different boost levels.
Do you have a guage on your maf??......i don't. But if i had a blower or turbo i would have a boost guage.
Just because we don't live monitor it doesn't mean its not important...
If you are really trying to say that boost vs. boost is a better comparison than giving both engines the same amount of air simply because a gauge exists is a pretty off base argument.
Just because we don't live monitor it doesn't mean its not important...
If you are really trying to say that boost vs. boost is a better comparison than giving both engines the same amount of air simply because a gauge exists is a pretty off base argument.
You should give the two engines the same compressor and the same amount of boost.
Just because we don't live monitor it doesn't mean its not important...
If you are really trying to say that boost vs. boost is a better comparison than giving both engines the same amount of air simply because a gauge exists is a pretty off base argument.
Yeah last time I figured out how much horsepower each engine made per CFM. Not hard to calculate, but I need to know these things: displacement, boost, and at what RPM the engines make peak power. Also what that peak power is.
If you can find that information about the Mach1 and LS1 cars you mentioned earlier, we can find out.
Ok....be a cool exercise i think. We would just do say 15psi. Next question.....should this be done off crank hp or whp?
Originally Posted by zz4camaro1980
Just because we don't live monitor it doesn't mean its not important...
If you are really trying to say that boost vs. boost is a better comparison than giving both engines the same amount of air simply because a gauge exists is a pretty off base argument.
Not what I'm sayin. I'm just sayin that apparently boost is important since that gauge exists and a cfm gauge doesn't.
Boost vs boost is the more fair comparison for sure.
Originally Posted by #MappinsgetsmeFappin
You should give the two engines the same compressor and the same amount of boost.
Can't really use the same compressor unless they would fall in the same efficiency range or you woukd over work the compressor for one vs the other. That in turn equals power lose for one and not the other.....which would not be fair either.
Maybe there is another formula to calculate correct size compressor for a given engine.
Ok....be a cool exercise i think. We would just do say 15psi. Next question.....should this be done off crank hp or whp?
Not what I'm sayin. I'm just sayin that apparently boost is important since that gauge exists and a cfm gauge doesn't.
Boost vs boost is the more fair comparison for sure.
Can't really use the same compressor unless they would fall in the same efficiency range or you woukd over work the compressor for one vs the other. That in turn equals power lose for one and not the other.....which would not be fair either.
Maybe there is another formula to calculate correct size compressor for a given engine.
Ideally done by crank hp. Whp muddles the results because now we have to take things like drivetrain efficiency into account, which can **** it up.
Yeah that's true, you'd have to find a middle ground unit that operates in it's efficiency range for both engines. That makes it harder.
I'm pretty sure there is a formula that can help determine an ideal compressor.
03-25-2016, 01:39 PM
