I posted this in the forced induction section and thought you guys would like to see:

https://honda-tech.com/zerothread?id=1223140

 

Nice numbers bud!

I'm lookin at your VTEC xover and wondering...you're on stock cams, and you've got a nice little dip around 5500. I also noticed that your a/f drops around there, but I wouldn't think that it would cause that much of a hiccup.

Did your tuner mention anything about this?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LudeyKrus &raquo;</TD></TR><TR><TD CLASS="quote">Nice numbers bud!

I'm lookin at your VTEC xover and wondering...you're on stock cams, and you've got a nice little dip around 5500. I also noticed that your a/f drops around there, but I wouldn't think that it would cause that much of a hiccup.

Did your tuner mention anything about this?</TD></TR></TABLE>

Thanks. I tuned it myself. The a/f curve (FJO wideband) was pretty rich (11.0:1) around vtec xover (5300 rpm set in AEM). I leaned it out a little bit but I was more worried with the misfire at higher boost levels. Whenever I get a better ignition setup, I'm going to redyno and raise the boost, adjust vtec xover for more linear curve, and play with cam gears. Also, I'm going to raise the timing as I had more room.

 

Definitely a nice setup. I responded to the other thread with some questions, please answer them if you have the time.

 

This was a project a long time in the making. Awesome, Quaalude.

 

Thanks Sharkcohen. Yeah, back when I was on Preludeonline it was the F-max kit with stock block and now to this. Even before then I had I/H/E.

 

nice numbers

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VisPreludeVtec &raquo;</TD></TR><TR><TD CLASS="quote">nice numbers </TD></TR></TABLE>
Yea man, I am actually going the same setup except je 9.0:1 pistons because I want some low end power, lol. Can you give me any advice when doing this? Thanks man!

 

Set up looks solid and honestly the most impressive fact to me is that you kept the AC..

I love when these DONT need to strip it but they do because it saves them 13 pounds and may net 3whp.. Whats 3 whp when you have 505, right? And when you have 505 whp you want weight over the wheels.

I realize some people remove for space issues, but I know many dont..

Build looks great - nice work tuning yourself. Sounds like when you get a couple of the bugs worked out, you'll be making some NICE power..

Good job and congrats !

 

Unless one has a digital A/F Meter and a wide band O2 sensor, he cannot tell what the A/F Ratio is(he can only guess by the little light thing gauge) - Therefor, i have chosen to run a little rich - how bad is this on my motor? I lean it out above 50% throttle...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by maxvtec7500 &raquo;</TD></TR><TR><TD CLASS="quote">
Yea man, I am actually going the same setup except je 9.0:1 pistons because I want some low end power, lol. Can you give me any advice when doing this? Thanks man! </TD></TR></TABLE>

The best advice is to not go cheap on the engine management. If you spend thousands of $ on your motor, don't run a piggy back cpu. There are plenty of options out there to choose from.

Drag_on....I had to kept a/c. In FL, it is the hot box here during the spring and summer, hell even winter. I also daily drive this car 70 miles a day to and from work so a/c is a must. Plus like you said, the weight is negilible with this much power. I also wanted to keep it a streetable car with all the comforts of a stock vehicle but with a **** load of power.

Sirludvtec...Are you turbo? If so, running rich is ok to a point. Try to run anywhere between 11.0-12.0:1. Any richer and you'll be dumping fuel and could wash off your rings. I say either get a wideband or go on the dyno. Widebands are pretty cheap now and you can do street tuning, which is worth lot. All my tuning with my maps was done either on the street or the track. The first run I just strapped it on and did WOT. I only touched up the fuel map in certain areas on the dyno.

 

wow....very nice numbers bro!

 

HP = HP (normally aspirated) * (1 + boost / 14.7)

505whp will be about 580hp at the flywheel

580 = HP(n/a) * (1 + 21 / 14.7)
580 = HP(n/a) * (1 + 1.43)
580 = HP(n/a) * 2.43
580 / 2.43 = normally aspirated HP =&gt; 240hp

Is 240hp n/a possible with stock cams and low 8.5 compression? Something doesn't fit...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kb58 &raquo;</TD></TR><TR><TD CLASS="quote">HP = HP (normally aspirated) * (1 + boost / 14.7)

505whp will be about 580hp at the flywheel

580 = HP(n/a) * (1 + 21 / 14.7)
580 = HP(n/a) * (1 + 1.43)
580 = HP(n/a) * 2.43
580 / 2.43 = normally aspirated HP =&gt; 240hp

Is 240hp n/a possible with stock cams and low 8.5 compression?
</TD></TR></TABLE>

that theory doesn't work, sorry

21 psi out of a T25 is different then 21 psi out of a T78

 

That's like saying 12V from a big battery is different from 12V from a small battery. No.

So how can the engine know what turbocharger is feeding it? 21psi is just that, regardless where it comes from. Are you saying it isn't 21psi, but something more? So now his boost gauge is wrong? Actually I agree with you there... I think something is wrong in his measurements, either the hp is too high or his boost is more then he thinks.

 

The battery comparison does not make sense. That would be like comparing a big nitrous bottle to a small one - you might spray the same, but the big one will last longer.

I PROMISE you 21 psi out of a tiny turbo is not the same as 21 PSI out of a giant turbo. Thats why an eclipse gets anemic at the top end even with the stock turbo spitting out 21 psi, but a giant turbo at 21 psi will put out huge power levels on the same engine.

the turbo sends a certain volume of air down the intake pipe at a certain velocty... hence its CFM.

as it goes into the intake manifold, it accelerates... smaller diameter. When a gas accelerates, pressure drops. Bernulli's prinicple.

as the turbo size increases, its CFM increases. the velocity of air moving through the intake manifold increases, and pressure drops. Remember, you are measuring pressure inside the intake manifold, you are NOT measuring volume of air.

When the turbo gets big, the CFM goes up, and so does velocity. if the amount of air going into the engine did not change (hence, how much power it makes), the pressure inside the manifold would drop.

****drawing in mspaint now ****

 

here


you've probably seen something like this before. each section of the pipe has the same volume of air going through per minute. The faster it flows, the lower the pressure.

if you increase the speed of the air coming in on the left, pressure will drop, but CFM will go up. If you increase the pressure of the air back up to the previous level, the CFM will be even higher.

This is how I understand it... I could be wrong... but I DO know that 600whp turbo cars don't run T78's at 50 psi

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Greyout &raquo;</TD></TR><TR><TD CLASS="quote">here


This is how I understand it... I could be wrong... but I DO know that 600whp turbo cars don't run T78's at 50 psi </TD></TR></TABLE>

they run at 49 psi

nice information there tho.

 

Greyout, you are most certainly right. With a smaller turbo, the housing is smaller so pressure is easier to build in it, with a larger turbo, its the opposite. You cannot get the same amount of hp out of a t25 at 21 psi as you can out of a super T60 at 21 psi.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by maxvtec7500 &raquo;</TD></TR><TR><TD CLASS="quote">Greyout, you are most certainly right. With a smaller turbo, the housing is smaller so pressure is easier to build in it, with a larger turbo, its the opposite. You cannot get the same amount of hp out of a t25 at 21 psi as you can out of a super T60 at 21 psi. </TD></TR></TABLE>

though your statement is correct, its not quite accurate as stating that the pressure is building to a level that depends on the size of the housing, as if you are blowing up a ballon.

the pressure is measured inside the manifold. Regardless of the size of your turbo, your throttle body and intake manifold is the same size. Increasing the size of the compressor causes the VELOCITY of the air, and thefore the total amount of air, to increase.

 

nice setup the guy has

 

wow, just wow. props to you.

 

Nice set-up....question....Is your downpipe custom?? What size are you running??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Greyout &raquo;</TD></TR><TR><TD CLASS="quote">here


you've probably seen something like this before. each section of the pipe has the same volume of air going through per minute. The faster it flows, the lower the pressure.

if you increase the speed of the air coming in on the left, pressure will drop, but CFM will go up. If you increase the pressure of the air back up to the previous level, the CFM will be even higher.

This is how I understand it... I could be wrong... but I DO know that 600whp turbo cars don't run T78's at 50 psi

</TD></TR></TABLE>

you are on the right track , but the importants between a small turbo and large turbo is that each a has a peak efficency island at a certian flow. If you crunch the numbers for your motor and find out what you peak CFM will be you can then determine what boost level you want , then you get a compressor flow map and plot your points, when you find a turbo compressor map that most or all of you points plot end up in the high efficency island that turbo is what is best suited to your app

an excelent point is that you can make a 20 ish psi on a lower reving motor but 2 facts are important. The flow of the motor is lowerdue to a lower rev so the turbo is still suporting the CFM the motor is requesting and all the while keeping that flow at 20psi. BUT the end all factor is that 20 psi is never the same from 2 different turbos. it all comes down to how efficently the turbo compresses the air. a t25 pushing 20 pounds is going to be WAY WAY out of it efficiency range and blowing rediculously hot air. yes it might be at 20 psi but hot air is less dense so it hass less o2 which means less postential for power. if you run a turbo that falls smack in the middle of its Efficiency island it will make boost at a much lower temp hence having the air denser = more o2 which will yeild more power.

20psi from one turbo != 20psi from anther.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kb58 &raquo;</TD></TR><TR><TD CLASS="quote">HP = HP (normally aspirated) * (1 + boost / 14.7)

505whp will be about 580hp at the flywheel

580 = HP(n/a) * (1 + 21 / 14.7)
580 = HP(n/a) * (1 + 1.43)
580 = HP(n/a) * 2.43
580 / 2.43 = normally aspirated HP =&gt; 240hp

Is 240hp n/a possible with stock cams and low 8.5 compression? Something doesn't fit...
</TD></TR></TABLE>

where did you ever get that formula? even if that were true, a lude won't experence a 13% drive train loss? from my understanding drivetrain loss wasn't 100% linear either.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by prelittlelude &raquo;</TD></TR><TR><TD CLASS="quote">... a lude won't experence a 13% drive train loss?</TD></TR></TABLE>

I think that number is about right. Stock, the H22A1 is "190hp", but what is it at the rear wheels? About 160 or so. That means 30hp is lost through the drivetrain, right? 30 / 190 = 16%

And you're right about it not being linear, and it all works against you. That is, a 200hp drivetrain may lose 16%, but one having 500hp forced through it will waste more hp because of increased internal friction.