'94 Bad A Z28

... a little disappointed, but when I think about it I guess it's not as bad as I think.


Mods:
CPT ProRace 4L60E - Yank ProYank Extreme 3600 (nitrous converter)
Home P&P LT1 Heads, flow *peak* 266/207 @ .600
Port Matched LT1 Intake
GM 847
Comp ProMag 1.52rr's
36lb Injectors
58mm TB w/air foil
Rebuilt LT1 (stock displacement) w/brand new GM Crank, LT4 rods/pistons
PaceSetter LT's w/off-road Y-Pipe - Full 3" exhaust
10-bolt w/Motive 3.73's, Eaton Pro-Posi, and T/A Girdle w/stud kit.
Aluminum drive shaft
MadZ28 Tune
A little bit of suspension stuff


So now for the numbers:

Run 1 - through flowmaster - 307.7rwhp/290.42rwtq
Run 2 - open cut-out - 335.89rwhp/312.98rwtq
Run 3 - open cut-out/locked converter - 340.61rwhp/322.35rwtq

These are SAE numbers from a DynoJet.


The first run stopped making power after about 6200 (flowmasters are that crappy) so the second run we only pulled it to 6400... and it was still climbing. The third run power started to drop off right at 6400 so next time I make it to a dyno I want to make a pass to 6800 with an unlocked converter and the cut-out open to see if it would still pick up where it left off on the second run.


I will post a video and picture of the graphs later, hopefully later tonight.


I also want to say nice work to Ion at MadZ28 because my air:fuel stayed right at 12.7-13.1:1 the whole time for every run.

jsetzer

Spin it higher and spray it....

You say "peak" numbers on the head, can I assume that the mid range isn't so great?

Also get some 1.6s on it.

MEAN LT1

Not too bad, you need to let me get my hands on it. You can always use a little fine tuning?.

'94 Bad A Z28

No the mid range is just fine, I just didn't feel like typing everything out.


The rings were gapped for spray, I just haven't put the kit back on the car yet. I can't really go much higher than 6800, lol... The first pull was to 6800, but after seeing where it stopped making power only pulled to 6400 on the second pass but it was still climbing so the third pass we pulled it to 6800.

'94 Bad A Z28

LMAO.... of course, lol. Are you planning on being in Orlando anytime soon, or should I plan a trip up there?

ssbowtie1

I'd say you have something wrong. You should be able to see ~330rwhp with stock heads and a cam. With ported heads you should be pulling better numbers IMO. Do you have a scan of your dyno pulls?

'94 Bad A Z28

330rwhp with stock heads/cam what are you smoking?!?! I wish... but I do think there is something missing, I was expecting something a little more than that.


I do have my dyno printout I just have to upload them and I'll do that later tonight, hopefully I get around to it.


You have to think about this when looking at my numbers though. I have an BUILT A4 which is a loss of power right there, I have a nitrous converter which is a loss of power n/a, and 3.73's which is another loss of power.

Without factoring in power consumption from the converter taking the loss from the auto and going to a 6-speed car that would put it right around 360rwhp. Plus whatever is lost in my nitrous converter brings it to around 380ishrwhp, down to stock gears brings it right back around 400rwhp, so like I said not too bad when I think about it.

'94 Bad A Z28

That and I still have some nitrous to throw at it! It was a nitrous car before the heads/cam and it is still a nitrous car.

ssbowtie1

I said stock heads and a cam, implying an aftermarket cam.

You ran 340hp with the converter locked, so you can rule out the converter loss. It is an A4 so dyno numbers are naturally lower, but I would expect to see higher numbers than you got. What was you A/F?

slomarao

i think its a little down on power too. And i dont think the things you listed that are hold you back from 400rwhp. Your talking 60rwhp there.
Get rid of the flowmaster, i had it on my car and swaped in a areochamber. Little quicker, quieter, and better mpgs(15-20miles more a tank)
Your first pull is equal to a m6 car with lts,exhuast, intake, 1.6rr.
Hell im shooting for 330rw with every bolt on, lightly ported heads and intake, and thats with mac headers too.

'94 Bad A Z28

Converter locked or not it's a nitrous converter so there is still loss.


I just took a picture of the graph, lol... here it is





The green run is the 2nd run, the one that was cut short thinking that it wasn't going to make any power past that or even up to that.

speed_demon24

Perfect example why flow #'s don't mean ****. Thats about on par with a stock headed car. And those excuses you listed are completly bs, but if you want to believe that more power to you. And 3.73's aren't costing you anywhere near 20rwhp My friends stock headed cc306 car put out upper 350's jfyi, and he had 3.73's too.

seawolf06

He's right. Those heads are probably hurting more than helping.

'94 Bad A Z28

Believe what you want, but I never said gears cost me 20 hp, everything together was what I was getting at but whatever. There are a lot more factors to pan out so you can not compare your friends car to mine really. Altitude, humidity, temperature ect... and corrections are just a generalization, and you really need to take measurements of everything to choose the proper correction method.


I could care less what your friends CC306 car dynoed, what did it run at the track? Is/was it an auto car or a manual car? I am going to try to make it to the track here in the next week or two and see what it does there... that's all that really matters anyways. Dyno numbers are just there for gloating purposes.

billymz28

not familer with the 847 cam. but is the torque supposed to be that low. i dynod 305hp and 325 tq on a exhaust only and no cat 93 z28 6 spd my car was a factory freak but that torque just seems to low to me