NA
125 Shot

I am fairly happy with my numbers. In the spray run I know that the drop off past 4kish is due to less n20 getting in the cylinder at higher rpms, but what about on the NA run? Will a mid range cam shift that torque curve higher? Or do I need some ignition upgrades?

This was on:
95 Z28 m6
Cold fusion wet kit
TR6's gapped @ .035
Hooker super comps through ORY and dumped
CAI, !Air, !EGR
Stock tune with raised rev limiter

 

I was loosing power topend too, but it was a sudden drop not a gradual dropoff like you. Anyway, it ended up being a bad coil, and msd coil fixed it for me.

 

I would recommend changing the fuel jets on the nitrous so that you get a targeted 11.5-11.7. 12 at most. You will get more power out of it that way.

Yes, a cam, will shift the torque curve, but it depends on the exact specs of the cam.

 

Bad Opti. Here's my stock dyno that had a bad opti, look at the crooked lines at the end. http://www.dfwls1.com/hosting/albums...10485/Dyno.jpg Definantly ignition related.

 

He doesn't have a bad opti.

 

that doesn't look too far off. Port the heads, that's the reason for the drop off. LT1's run outta breath fast at high rpms with stock heads.

 

It is def not a bad opti I wish I would have logged my pulls so I could see what all was going on... oh well. It just makes me mad that the peak HP number would be MUCH bigger if I could stretch that torque curve smoothly past 5300.



-Ignition wise I don't think a coil could hurt, but I figured it was just the design of the lt1 not breathing. But hey, 500lbs @ 2500rpm sure is fun..... (JSetzer says this as his lil 10 bolt is laughing at him)

 

- MadZ, should I fatten up even my base tune? N20 is a nasty beast and I may move away from it.... But I do not feal real safe pushing leaner than 13.0 top end. That was on less than ideal bottle pressure, so it would probably be even leaner on a hot day. That was @ 700psi.

 

I think you are misunderstanding his advice. He basically told you to leave the base/NA tune alone. It looks good. He is telling you to richen up the fuel, because you are running too lean on the N2O. If you consider that your base tune is slightly below 13.0:1, and when you spray it leans out, it means that your N2O tune is too lean. I would agree... richen the fuel jets to get it below 12.0:1.

Why would you dyno with 700psi in the bottle? You just gave up 12% of the N2O HP by not running at least 900psi. Yes... with 900psi you will get even more nitours flow, it will run much leaner and you are going to break something. You were probably "lucky" you only had 700psi.

 

Yours looks like a bad opti his does not. His looks pretty accurate for a stock motor.

 

Yes but I was curious if there would be enough in there to justify tuning for NA. I will go one fuel jet bigger for the time being IF I do any more spraying. I think I would rather sell the kit and put the money towards a cam. But hey, thats why we ask questions here.

With me just waiting to break something, 12% was not worth the $100 for a bottle warmer. 399saeHP is pushing it for this car anyways.

On a side note my first N20 pull they didn't open the bottle but there was some in the line. 500lbs and only 275HP... it was kind of funny.

 

* New question*
They took my air/fuel on one of the tips, but my cutout was open before the axle. They told me it was still accurate, I would not think so. I was spitting fuel out the cutout. Should I go back to the dyno and have it checked with the cutout closed or something?