ScreaminRedZ

iTrader: (3)

I installed my bottle heater and ordered up some more fuel jets and then hit up the dyno today to dry and get the nitrous dialed in.

Basic mods: Trickflow 215's, 230/236 .583/.583 (with 1.8 rockers) 112 cam, most of the bolt-ons, 12-bolt w/4.10's and spool.

I also removed the high flow cats since last time.

Previously, the car made 424/374 with the cats installed, but the cutout open. Here is today's graph with the cats removed. The blue is with the Borla capped, running through the muffle, and the red is with the Borla uncapped.



Next up I tried dialing in the nitrous, via fuel jet changes. The blue line is the 100 shot and the red line is the 150 shot.



As you can see from the air/fuel, I can't seem to get it right. These were both running a much richer fuel jet than the kit recommends, but it still went lean and then went rich up top.

I have a ticket open with HSW. Not sure if it's a problem with the solenoid or something else.

chrs1313

iTrader: (24)

why the 1.8 rockers...just curious...

ScreaminRedZ

iTrader: (3)

My cam had .551/.551 lift with the stock rockers. It made good power cam only, but I wanted more lift out of it. I needed rockers for the Trickflow heads so I figured that would be a good way of getting the extra lift I was looking for without having to spend extra on the cam.

Looking back I probably would have gone with a bigger cam as I was expecting a bit more power with this setup and will probably end up swapping cams later anyway. Oh well, live and learn.

BrianC98Z28

iTrader: (11)

why the dip in a/f NA and N2O from about 3200-4100? You could try leaning and richening up the areas desired in the tune alone with the jet changes and should get you where you want.

ScreaminRedZ

iTrader: (3)

Not sure what's up with that dip there, but it's not bothering me. On the nitrous that dip is actually close where I want it. It's where it raises way up that's bothering me. I don't think messing with the tune will help since it's pretty much where I want it NA. If I richened it up via tune to get it where I want it on the spray then it would be way rich NA I think.

chrs1313

iTrader: (24)

yeah the way i always look at it what is the difference in price you can sell you old cam for 275-300 and a new one is like 380 so like 100 difference...plus the time to install it yourself...

anyways sorry i dont know enough about tuning to help with your problem...hyjack off

ScreaminRedZ

iTrader: (3)

Yeah, I definitely hear that. The car actually broke and the guys at RPM were kind enough to tow it to their shop so I could have it fixed. If I was close to home I would have fixed it myself, but it was hundreds of miles away so...haha. While it was there I decided to have them put the heads on and tune it. It was a spur of the moment decision and I was already spending more than I had planned (due to the extra work I was having them do instead of just having the rear fixed) so I was trying to save money over paying for more parts and install.

The car had previously made 400 rwhp cam only, so I figured the cam would be ok. On their dyno it baselined 389/353 before the heads and then 430/380 after the heads and rockers (with nitrous tune). At a different dyno up here it made 424/374 and then I pulled the cats off and it made the 432/386 you see here.

The nitrous problem seems to be something new that has popped up since it's reading differently now than it was when it was tuned. The motor runs read the same on both dynos though, so I think it's something specific to the nitrous side of things.

Thanks!

Slowhawk

iTrader: (12)

The big #'s from the hit are from being lean,as you know.The 100 shot richened quicker than the 150 which tells me it's probly fuel pressure drop.Most of the kit's I do seam to require the 150 shot fuel jet with the 100shot nitrous jet to get A/F in check.This is mostly due to undersized fuel systems.

Also,when you see it running lean it is not a good idea to finish the run.Good way to crack a piston.

ScreaminRedZ

iTrader: (3)

The .034 jet was the recommended fuel jet for the 150 shot. The blue line here is with a .040 fuel jet, but a .052 (100 jet) on the nitrous side. Way past the normal "fine tuning" that is necessary with a basic kit I'd guess.

The car has a Racetronix fuel pump and 42# injectors (not that the injectors matter much on a wet kit). At the level I'm at is it possible that that's not enough on the fuel side? I know the stock pump would have been iffy. I do want to get a permanent fuel pressure gauge installed so that I can tell for sure.

Also, I was driving the car on the dyno, so if anything broke then it was on me.

Appreciate the time