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 19 2004, 03:15 PM Post #2
Moderator Group: Advanced Members Posts: 863 Joined: 23-December 03 From: Tulsa, OK Member No.: 5	Yeah, I really didn't want to do headers as they are such a pain, especially since I'd have to convert to mid length 94/95 style or long tubes to really see good gains. However, I keep coming back to the TPIS long tubes for 96/97 cars. They are supposed to have better ground clearance than the other LTs, and have an offroad ypipe available that hooks up directly to the 96/97 style catback. They are a little more expensive than some of the others, but still under $900 for coated headers an ypipe. I think those alone should probably put me over 330RWHP.