Jim_H

Andy,
I don't have a 5th gear after to compare to. My before run of 272 just wasn't right. I had run a 301 on a dynojet a few months earlier before I extended the 2 1/2" from the X Pipe back. That being said, it pulled like a train after the install and the day before it's current body was killed it took me to about 168 with no trouble at all. Louis said I was disappearing into the horizon quickly. BTW, approaching redline in the first 4 gears is fun, approaching redline in 5th gear was much different. I felt 2 strange obstacles creeping up stomach towards my throat
When I get my RSU928GT home next week one of the first things I will do is Dyno it. Run the 2 1/2" exhaust, dyno it and then install the SC... and dyno it.

Jim_H

Yep, Bill showed close to 15hp per psi of boost.

GoRideSno

Jim,
Did you get to use the G-tech before the incident?
IIRC you made around 440rwhp in 5th after the SC. Remember we did all the tuning runs in 5th and just went to 3rd to see the difference.
440-272/6=28rwhp per psi of boost. I was off with 29 because I thought you made 262 in 5th before but that was Seth. So....28 not 29 but still over 10% of NA HP per psi boost.

When Tom has time hopefully he can give us a print out of all the runs.

Your's and Seth's cars were the first 2 intercooled 5 speed cars to be dynoed with my system.

Seth was close to 25rwhp per psi boost with the Jag/Eaton intercooled system.

Mike's non-intercooled Jag/Eaton M112 gained around 90rwhp at 4.5 psi or about 20rwhp per psi boost or about 8% NA HP per psi boost.

The only other supercharged intercooled GT I have seen before and after charts for only made 20rwhp per psi boost or around 7% NA HP per psi boost....isn't that right carl? Hey that's not bad though. Chris's GTS gained about 7.5% per psi boost....with no water in the intercooler.

We really should inspect for dammage before you make the swap. The drive is only about 1/2" below the hood.

Andy K

Scott M.

Jim;

Thats' why it is important to have a female passenger restraint system along for the ride, to hold those obstacles in place.

Scott

Bill Ball

Carl said:

"but Andy, Bill Ball got 50 HP on 5 psi of boost with your installation. That's 10 HP per psi. Isn't that what I read?"

Carl:

Where did you get this information? You know I like you and what you do, but you are occasionally very loose with math and facts. My sig gives the facts. It's in every post I have made. Note my setup is not intercooled too. Puposefully very conservative. Seth's car using the same SC but with an intercooler pulled considerably more and we didn't have his belt tight. What the heck is this argument about anyway?

Carl Fausett

Sorry Bill... I was wrong. I went back to your post to see where I read that. This is what you posted the day after you installed it at the DEVEK shop days.

My math is fine, fellas - check it your self. The before and after HP gain was 72 HP (do the math yourself), the Dyno chart excerpt is below. 72 HP divided by 5 (PSI) is 14.4 HP per psi.

That is very reasonable - right in the neighborhood where most results on 32v SC motors seem to fall, Tim's too. IMHO, if fueled correctly, all the boost producing methods (turbo, positive-discplacement, centrifugal) will land in the same numbers of HP generated per PSI of boost. The variables will be the miles and condition of the motor, and the variations in dynos, and cams between certain 32v engines.

This is going to be a near constant based on the amount of energy available in a gallon of gas.... next time you are at the dyno - ask the rice motor boys how they do with their Accura's on boost and Civics and all. Remove Nitrous and water injection and Methanol from the conversation - just straight boost on straight gasoline.
You'll find 15:1 is a very common number across the board.

In other posts - I have said that 32v motors seem to produce 15 psi per pound of boost and 16v motors seem to produce 13 or so psi per pound of boost (the head design and valve train on the 16v leaves some on the table). With intercoolers, I have seen as much as another 5 added.

Andy - my eyes are fine. I know BS when I see it!

GoRideSno

Conveniently you have cut off the boost chart. it was 4.9 bwt.

Edit: As bill mentions below, it was 4.8. 72/4.8=15.

Andy K

Jim_H

AARGH! I forgot about the G Tech. No I didn't get any runs on it. Don't worry, it wasn't in the Shark when it was killed. Where should I send it?

I do remember being around 440 before doing the run in 3rd

The SC sounds fine post crash. I have ran the engine numerous times checking for noises leaks etc.

Bill Ball

If you want to get precise, I think we read 4.8 lbs of boost at peak. Whatever. Everyone focuses on peak HP. I hope you guys are careful about the RPM, etc. because peak varies a lot from run to run. I was much more interested in torque and where the torque happens. The guys that get the bigger HP gains, get relatively smaller torque gains. I'm real happy. I have far more torque now than my stock tires can handle. I now have another reason for a wheel/tire upgrade.

Jim_H

I don't understand? What BS?

Jim_H

Adds new meaning to "hold on Babe".

Carl Fausett

No, Andy - lower your paranoia for a moment and look at the picture I posted.
I was trying to show - precisely WHERE I got my numbers that I was using.

Wait - I forgot the new "check your eyesight" font:

I took the Max HP (posted in the picture from Bill's dyno chart) and subtracted the Base HP (posted in the picture).

There is no subterfuge here, Andy.

Herr-Kuhn

HP per PSI is VERY misleading. To do a fair comparision you should integrate the area under the RPM-torque curve to tell the real story....you are really looking at useable power when you do this. European car is now using this type of comparison when they look at forced induced cars. There are too many cars with centrifugals and overly large turbos with huge lag that are chasing a peak HP number....and for the life of me I just don't understand why. A turbo that comes on at 4500 RPM and makes all its boost at once is useless in my opinion, even on a track. I think a car that will start to build boost at around 2,500 and be on full tilt by 3,500 and can hold full boost to the redline is a nice setup.

mulik51

Just was searching for CIS stuff and found this.
I don't get it, why would you integrate the area under the graph? That would give you the function...did you mean integrate the actuall curve? Then it would give you the total amount of hp generated in the run...how is that usefull. Just a curious mind...
And to integrate the curve it would be pretty hard, becouse the curves are usually wierd looking and it would be pretty hard to fit a an algebraeic function for it....

Thanks,

Klim

James-man

I would suspect that a sample from multiple points across the critical range* averaged would provide an OK ball park.

The curious thing about measuring performance and rationalizing lower peak for a flatter HP curve is the fact that under load, you would spend more time in the 4000-5000 RPM range than the 5000-6000 range if you have a 6000 rpm hp peak. If we were to look at assessing performance potential mathematically, you should account the relative time spent in each incremental RPM to reflect the work that can be done. I guess that I am suggesting that greater weight be placed on the lower part of the HP curve (that resides within the critical range) because the car will not pull has hard there and will take longer to move up the RPMs. A weighted average of sorts. As you decrease the size of the RPM measurements your weighted average would approach what integration may tell you. The answer will be lower than peak HP, is therefore much less interesting than Peak HP, but would say a lot about relative performance between two different HP curves. Mark Kibort has written about area under the curve and I think that he is spot on. No need to integrate, but time series is a new variable. Milliseconds in each of the slices of RPMs is not readily available data, so we can probably use HP differentials to establish up a set of weight proxies. Just thinking out loud here.

* critical range would be whatever RPM band that means the most ot the person doing the analysis - probably, for the agressive folks, peak HP or Rediline RPM and the subsequent upshift RPM.