New dyno, nice gain - F-Body Road Racing and Autocross Forums

Well, I finally got around to getting another dyno done after fixing a couple of things on the car. The first thing was putting in the LT4 Knock Module in place of the LT1 module that came with the stock ECM. Once again I really don't understand why SLP left the stock ECM (including knock module) in these cars when they put in the LT4 engines, but it sure makes for a nice change when you "fix" it. I also had been hearing a "ticking" at startup over the last month or so, and when I finally got a chance to check it this past weekend I discovered a couple of loose exhaust manifold bolts on the driver's side. I don't think the exhaust manifold bolts were loose when I did the previous dyno, so at this point I'm going to say that the big gain over last time (11RWHP and 8TQ) came from the LT4 knock module. This would tend to hold up as I was seeing some knock retard after the last dyno run when I did some monitoring using Datamaster. After retightening the manifold bolts over the weekend I am now seeing ZERO knock retard (both on the dyno and on the street). So, the final gain from the ECM tuning and LT4 knock module at this point are:
29RWHP and 21TQ

This now puts flywheel HP at 366HP, and I'm hoping to increase it a little more as the car is still running a little rich (about 12:1-12.5:1), and by adding a few mods. My goal at this point is to get to 330RWHP so that the 330 HP stickers on the hood actually match up to something!

Once again, the only difference between dynos is a tuned ECM and the LT4 knock module, everything else is stock:
(IMG:http://www.lt1.net/images/Firehawk/ecmdyno2.jpg)

LT4Firehawk View Member Profile	Feb 18 2004, 04:02 PM Post #1
Moderator Group: Advanced Members Posts: 863 Joined: 23-December 03 From: Tulsa, OK Member No.: 5	Well, I finally got around to getting another dyno done after fixing a couple of things on the car. The first thing was putting in the LT4 Knock Module in place of the LT1 module that came with the stock ECM. Once again I really don't understand why SLP left the stock ECM (including knock module) in these cars when they put in the LT4 engines, but it sure makes for a nice change when you "fix" it. I also had been hearing a "ticking" at startup over the last month or so, and when I finally got a chance to check it this past weekend I discovered a couple of loose exhaust manifold bolts on the driver's side. I don't think the exhaust manifold bolts were loose when I did the previous dyno, so at this point I'm going to say that the big gain over last time (11RWHP and 8TQ) came from the LT4 knock module. This would tend to hold up as I was seeing some knock retard after the last dyno run when I did some monitoring using Datamaster. After retightening the manifold bolts over the weekend I am now seeing ZERO knock retard (both on the dyno and on the street). So, the final gain from the ECM tuning and LT4 knock module at this point are: 29RWHP and 21TQ This now puts flywheel HP at 366HP, and I'm hoping to increase it a little more as the car is still running a little rich (about 12:1-12.5:1), and by adding a few mods. My goal at this point is to get to 330RWHP so that the 330 HP stickers on the hood actually match up to something! Once again, the only difference between dynos is a tuned ECM and the LT4 knock module, everything else is stock: (IMG:http://www.lt1.net/images/Firehawk/ecmdyno2.jpg)

LT4Firehawk View Member Profile	Feb 18 2004, 05:12 PM Post #2
Moderator Group: Advanced Members Posts: 863 Joined: 23-December 03 From: Tulsa, OK Member No.: 5	Chris, do you think you could get me a copy of that test, or get me info on where you got it from?? I'd really love to have it. As to the tuning, it is definitely a bone stock LT1 tune from the factory and had the LT1 knock module. QUOTE Looks to be on equal par with LS1 cars.... A little higher actually. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/biggrin.gif) We compared it to the shop owners WS6 LS1 with a lid and it was slightly higher across the board on HP, significantly up on TQ on the low end, and pulled to a lot higher RPM. Like I was telling someone else, the HP on an LS1, the TQ of an LT1, and revs past either of them. I still think I'm running a little rich, but I'm not sure how much more I want to lean it out. It's running 12:1 on the dyno, with O2 numbers around 920-950. But on the open road on a 4th gear pull, the O2s were around 865-890 (must be the Ram Air working). Anyway, I'm definitely very happy with the results at this point, although I think I may put a Hotcam or something similar in it to see what I can get. The amazing thing to me is that this is through the stock exhaust manifolds, cats and 48mm TB. I may also go ahead and get an offroad pipe (mainly for sound) and a 52mm TB to see if they help out on the power any.