Stock MAF limit = 350hp

[NateDogg]

I was talking to Rune, the fellow who ROM-tuned Don Nimi's (PDM-Racing.com) car. He showed me the dyno charts of Don making 330whp at 12.5psi on STOCK MAF and 370cc injectors.

He said the MAF did no max out and guesstimated that it would take 350whp to max it out.

So, what I'm suggesting is don't go wasting time and money wiring up a Z32 MAF if you are only gonna use it with 550cc injectors.

Any other experiences?

[KATwo40]

That's very interesting.

[TheOne]

which MAFS though? S13 or S14? the S14 is probably a tad bigger on the inside.

[hannibal]

Thats very interesting. People have shown that the stock MAF hits 5V around 250whp so I'm wondering how he did this (without hacking the MAF).

I also dont see how 370cc injectors can provide fuel for 330whp.

[crzycav86]

Yeah... he's gonna have to pop in here and give his reasoning before I believe that.

[SR20Essex]

I'm at 13lbs boost 255whp and my SAFC2 is almost maxing out everything at points during the rpm range and I'm still running a bit lean, 370cc injectors, stock MAF, S14 SR20det(VVT). I seriously doubt its that much different for a KA.

I mean .4ltrs is going to need only slightly more fuel and slightly more air, but probably similar HP considering the MAF and injectors are basically the same.

[Craving4Boost]

what octane was this at....

[crzycav86]

I'm at 13lbs boost 255whp and my SAFC2 is almost maxing out everything at points during the rpm range and I'm still running a bit lean, 370cc injectors, stock MAF, S14 SR20det(VVT). I seriously doubt its that much different for a KA.

I mean .4ltrs is going to need only slightly more fuel and slightly more air, but probably similar HP considering the MAF and injectors are basically the same.

In terms of air flow, it's exactly the same.

what octane was this at....

As this guy alluded to, air flow is only part of what makes power. If it's true, then this car has one hell of a tune.. and a really low bsfc.

There's more to this setup than has been disclosed. Perhaps he's running it at higher base fuel pressure or something.
Modified by crzycav86 at 2:54 PM 11/15/2006

[KATwo40]

what octane was this at....

Octane should have no effect on what AFR reaches MBT. Only the timing would be considered here.

[deviousKA]

It is simply more efficient that most turbo setups, made possible with what I presume to be well selected turbocharger and associated equipment, and proper tuning.

There is not enough examples of well thought out, well tuned configurations for this to be deemed un-normal. Even simple setups like this can benefit from a professional approach.

[Edub1]

Sounds like he is just turning up the fuel pressure real high and pushing the injectors passed their normal limit.

So, maybe when the MAF maxes out the setup just dumps fuel. I'd like to see some more in depth explaination.

[RyanAwesome]

It is simply more efficient that most turbo setups, made possible with what I presume to be well selected turbocharger and associated equipment, and proper tuning.

There is not enough examples of well thought out, well tuned configurations for this to be deemed un-normal. Even simple setups like this can benefit from a professional approach.

+1 i would really like to see what kind of gains could be made on a ca or sr by just optimizing the flow of gasses, fuel and tuning. try and do everything possible without changing the turbo out.

[Florida240sx]

My guess is liek what is said the maf maxes out and he just keeps it adding fuel... If it's on a dyno it can be done but if the set-up changes then he'll probably have major issues... or maybe he has an ace up his sleeve or a freak motor

[NateDogg]

What I said was that the MAF did not max out IE. Did not reach 5.11V. I dont think it even reached 5V.

The amount of air injested should be similar for similar power levels. So, the limit of this S13 DOHC KA MAF should be similar to others.

[C-Kwik]

Just an FYI, Don's set-up is pretty comprehensive. I can't comment on the MAF voltage as I can only rely on testing done by others. But as far the power he's reaching, his set-up may allow him to run slightly leaner to bump up power and make better use of the fuel flow capacity. He retained a 9.5:1 compression, is running a race head, turbo cams, water injector, and intercooler sprayer. I've known Don for a while and his attention to detail is top notch. I'm not surprised he's making such great power for 12.5 PSI.

http://www.pdm-racing.com/features/240sx2.html

[Craving4Boost]

damn c-kwik I almost didn't reconize it was you with that new avatar. where the swat man go?

[C-Kwik]

Ask Matt about it. I guess I better get my work done since someone finally took notice. I have the dunce cap on at the moment.

[nchopp]

Ask Matt about it. I guess I better get my work done since someone finally took notice. I have the dunce cap on at the moment.

[audtatious]

Ask Matt about it. I guess I better get my work done since someone finally took notice. I have the dunce cap on at the moment.

I'm abusive to the Mod team too

[Edub1]

If you look at the pictures you'll notice that the stock MAF is on an N/A car with a cold air intake. They go on to describe a turbo setup.

I think the stock MAF was before they built the motor.
Modified by Edub1 at 5:10 PM 11/16/2006

[C-Kwik]

I'm abusive to the Mod team too

Yeah, but I like it rough.

[nchopp]

Yeah, but I like it rough.

[KATwo40]

Nevermind.
Modified by KATwo40 at 3:11 PM 11/17/2006

[Edub1]

You are right but what does this have to do with the topic? A lot of people do miss that point though. Like that video of the SRT motor that made crazy HP but the torque was half the HP.

The question is whether or not they can make a motor so efficiant that they can get X power while only using enough fuel and air so as not to over drive the MAf. Considering all the radical stuff they are doing and super high compression with water or whatever injection, I'd say it might be possible. It's only about 30% over what is expected of that MAF. But then again they are using a T3/T04B so they are flowing some air.

Anyway, like I said, is the stock MAf used in the final setup? Because that one shown is on an NA motor.

[KATwo40]

This post has been relieved of stupidity!
Modified by KATwo40 at 3:12 PM 11/17/2006

[C-Kwik]

I think you missed my point.

Let's say we have an engine with a BSFC of 12.0:1 and we wish to make around 300hp. The formula used to calculate expected airflow requirements would reflect a need for somewhere around 32lb/min.

Now, if that 32lb/min was sucked through the MAF sensor all at once during a narrow portion of the upper rpm range, the MAF would easily max out. However, if we were to spread that 32lb/min out over the entire rpm range, we would still achieve the same horsepower, but the torque band would be broad and flat. Consequently, the MAF would not see a large enough wieghtflow at one given time to reach a full 5.11v.

It sounds like you are implying that HP is an aggregate total of torque made over the range of RPM. If that's the case, you're incorrect.

Revving to a high RPM is not a good example either. HP is essentially a measure of how effectively torque can be put to the wheels. I'm not talking about drivetrain losses, but rather how well the existing torque can be multiplied by the transmission to provide torque at the wheels relative to wheelspeed. If you were to take several engines making 300 HP and gear them all so that they hit the same wheelspeed at the RPM at which 300 HP occurs, then every motor will have the exact same torque being applied to the wheels at that very moment.

Airflow is a function of displacement, volumetric efficiency and RPM. HP and torque are both momentary measurements and is not an aggregate of any other number. So at the moment a car is making 300 HP or the associated torque figure, it will be sucking in a certain amount of air. You can't somehow spread it out over a lot of RPM's....

What DeviousKA is referring to is simply choosing parts to maximize efficiency thoughout the system.

[KATwo40]

I found what seems to be a pretty decent article explainificating the theory of hp.

http://www.procivic.com/pages-....html

What I typed above luks stoopid.

Thanks.

Modified by KATwo40 at 3:04 PM 11/17/2006
Modified by KATwo40 at 3:05 PM 11/17/2006

[C-Kwik]

It factors in time, yes, but the figure is still momentary. And HP is a representative number that describes what work a particular force will do over a period of time. More specifically, 1 HP = 33,000 Foot-Pounds per minute. This is equivalent to moving a 330 lb weight 100 feet in one minute. But if you were to move the same weight 50 feet in 30 seconds you still get the same HP. 25 feet in 15 seconds is still 1 HP. No matter how many times you cut this down it will still be 1 HP. So, for that moment in time (as time approaches 0), it will still be producing 1 HP. HP is representative of the work it would do, but HP in a motor changes with RPM.

Actually HP doesn't mean much without a transmission. At least in terms of cars. The acceleration of a car in a given gear will be directly related to the torque curve. Where torque is highest, the forward accelerative G-force will be highest. If all cars only had one gear ratio, Torque would be the only number that matters.

Consider for a moment, a motor that produces 100 ft/lbs of torque at all RPM's. Lets say this motor spins to 10,000 RPM It's not going to make any more torque at 10,000 RPM than at 1,000 RPM. Yet the motor will be making 10 times more HP at 10,000 RPM than at 1,000 RPM(19 HP vs 190 HP). In a given gear the acceleration rate will be the same(ignoring frictional losses). But what happens when apply 190 HP at 1000 final RPM. You gear down the speed by 10:1. The result is now 1,000 ft-lbs of torque at 1,000 RPM. You're now getting 10 times more force at the same speed. As you can see, the HP and torque are both 10 times more at 10,000 RPM than at 1,000 RPM. This tends to be hard for many to grasp as HP and Torque Peaks tend to occur at different RPM's, and manufacturer's don't publish the HP figure at torque peak and Torque at the HP peak. People tend to believe they are two different things. They are simply a different way of looking at the same thing. Scientifically, they represent different things, but for all intensive purposes, neither is more important than the other as long as you are looking at a dyno and can see the entire scope of the curves involved. If I were to choose one to look at when determineing how powerful a car truly is, I'd look at HP as it factors in RPM already.

[C-Kwik]

I found what seems to be a pretty decent article explainificating the theory of hp.

http://www.procivic.com/pages-....html

What I typed above luks stoopid.

Thanks.

Modified by KATwo40 at 3:04 PM 11/17/2006

Modified by KATwo40 at 3:05 PM 11/17/2006

You changed what you posted while I was typing my last post out. Looks funny now. lol.

The article confirms what I've been saying all along for the last few years. I almost thought I found a site that explains it as clearly as I want, but alas, I'll still need to some up with my own one of these days. The article is good and accurate, but I think it still may leave some with many questions. And for the record, even a stock base model Civic will make more tha 400 ft-lbs of torque in 1st gear and do it well over 8 mph. One day I'll provide a better description. But as my avatar suggests, I have more important things to do first.

[KATwo40]

Hehe, sorry for the ol' switcheroo, there C-kwik. Didn't mean to do that to ya'.

So, would you agree that tuning for MBT would yeild higher hp seen on the stock MAF sensor?