While its been recalibrated, I need to get a stock 928 on this dyno and see what it pulls so I can better judge how much is actually being made.

Unfortunately the dyno I normally use was sold and is no longer there.

 

If this dyno is on par with others, this means the cams are bumping the power by, what, like 60rwhp??

Dan
'91 928GT S/C 475hp/460lb.ft

 

Yes from S4.

Let's just say these cams are no longer the restriction for HP.

 

Attached is the dyno graph, (printer running out of ink.....)

The top flat line is the AFR, bottom flat line is boost line (N/A so flat).

I dont have a stock S4 graph handy, but I'm sure someone can overlay it for us all.

 

So ya..yer gonna get flown down now for cam install. When in November is a good time.


Wifes gone a large portion of the month for work, so im goin nowhere.

 

Yesterday I flew home and picked up my car from Colin. Mid way to my home, stopped on a traffic light I had to sent a text to Colin with a comment: Holy S**t!
Now I believe!!!!! I was completely blown away! The motor is pulling unbelievably hard all the way to redline, that thing has some more ponies released from their prison! The last sharktune on the dyno made another step up in power from what I had.
Over 300 ponies on the wheels? Yes I definitely believe that now.

Thanks Colin for this. What was initially an expense that i did not budget for and really did not look for, made out of necessity due to my pitted cams, has turned into a must do mod for anyone looking to to increase the power without going the supercharger/turbo charger route and keeping pretty much everything stock.

 

Danny , there is 32+ more RWHP waiting with headers /X/ 2.5 inch system , that will really push you back into the seat .

 

Ok another update.

Danny took his 928S4 with stage II camshafts through our emissions testing and here are the numbers.

Driving test (40kmph)
HC ppm MAX 87.00 Reading 7.00 Average 20.00
CO% MAX .59 Reading 0.01 Average 0.06
NOX ppm MAX 878 Reading 560.00 Average 111.00

Idle Test
HC ppm MAX 82 Reading 13 Average 23
CO% MAX .50 Reading 0.00 Average 0.04

So emissions can be passed, this car also has no air pump on it.
More to follow on Terry's car.

 

I finally got my hands on Terry's car! I first verified all the settings for the camshafts. And noticed that his ign leads were in less than stellar shape.
So I replaced them with a set of my nice leads.

Next I took it up to the dyno and adjusted the tune. However I quickly found that Terry's MAF was not in great shape, the car was either running at 12.4AFR or 13.1, there was no other numbers. And in order to get it to 13.1, I had to pull MASSIVE numbers out. It was still going uber rich in the top end too.
The installed WB and the dyno both reflected these numbers.

That said, I leveled the AFR as best possible, and looked at the ign table as much as possible. There was not much gain to be had there over what I had already previously added.

Now the runs were done in 4th gear, and the car was at a good temp with a little heat soak. The graph and numbers are attached.
BUT AGAIN, my CAVEAT is that I have NOT put a bone stock car on this dyno to confirm its 100% accurate, I believe it to be close, but have yet to confirm. I have a car lined up for the base test, I just need to arrange a time with the owner. (I do think it reads a little high, but not astronomically so as I put down 325rwhp with the cams adv 8 deg on an 87 bottom end 5 speed on a dyno I knew to be accurate.) /END CAVEAT

So Terry's GT has Stage II with triflow. I have to say I am impressed with the tri-flow! They did lower peak HP from 6114 that Danny has to 6083 on Terry's, but the Torque curve had the nice peak like the stage II does because of the flappy, but after the dip from the flappy change, the torque just climbs and puts the peak at 4635rpm vs the 3432rpm peak with stage II.

So the GT w/ MSDS headers, high flow cats, dynomax no drone mids, and a gibson rear, dual 2.5" put down best of:
352.2 RWHP @ 6083RPM [WCF 353.1]
329.8 RW FT LBS @ 4635RPM [WCF 330.6]

Danny's Stock 91 S4 (no exhaust mods) put down a best of):
329.2RWHP @ 6114RPM (201.3kmph) [WCF 325.8]
291.4RW Ft Lbs @ 3432RPM (107.8kmph) [WCF 283.3]

So if we do it based off weather correction factor the difference between exhaust and tri-flow from base stage II is:
353.1 vs 325.8 = 27.3 RWHP
330.6 vs 283.3 = 47.3 RW Ft Lbs
The majority of the torque increase was from the triflow modification from the graph, and seeing what other owners have seen.

 

Attached is the stage II followed by the stage II w/ tri-flow and exhaust to show the differences in the power curve.

 

Terry's emission as I tested today.
Driving (40k/ph):
HC ppm 17.00
CO% 0.01
NOx 700.

Idle test:
HC ppm 17
CO% 0.00

Another no issue pass with big cams and stock brains!

 

I think you need to take into account the fact that Dannie's car is an automatic and Terrie's car is a 5 speed. As I recall you did the swap from Automatic to 5 speed on your own car and reported how much significantly rwHP improved when you did the dyno. You posted it on a thread but can't remember which one.

Either way NICE NUMBERS, tempted to get a set, tired of getting beat by these modern 4 cylinder cars.

 

WOOPS!

Thanks for that catch!

yes Danny's car is an automatic, Terry's is a GT (5 speed).

I did convert my car from an auto to a manual, and that is why I couldnt use the numbers it put out or for any real data.

Thanks again!

 

So..when's a good time to get here and do mine.

 

What set do you want Jeff?
Sharktoberfest weekend?