Gen1 dyno run; not too shabby....

[obaa996]

Torquefreaks in Portland had their dyno day yesterday. It was a great event; the weather was just about perfect (70 degrees, 30% humidity), and a bunch of nice people out there. I was on a tight schedule, but Jason was very accomodating, and managed to slot me in pretty much immediately; thanks Jason!

They had a new C6 out there earlier in the day. I saw it in the lot, and his numbers were posted on board. I think he peaked at 340hp or so. I figured my old Gen1 was in for some trouble... It's got smooth tubes, S&B filters, ****** headers, Roe cats, and Dynomax bullets, but did benefit from a Arrow rebuild (due to head gaskets) about 3k miles ago. There's an Al flywheel in there too, but supposedly that doesn't affect dyno numbers? I figured I could do a bit better than him; maybe 380 or so? Well, my dyno graph is below. Whacha think?

415hp/476ft-lbs. Not too shabby, I think....

They did flag an issue during the runs though. They mentioned that they heard a lot of pinging (I couldn't hear anything from inside the cabin), and showed me that the car was running way lean at the higher rpms. Looking at the a/f chart, something goes wrong at 4k rpm; it goes off-the-chart lean and stays that way until I roll off.

Is there something that happens at 4k, or something is supposed to kick in? I'm going to give the shop a call, but curious if there is something simple I can check for.
At any rate, I'm pretty happy for an 11 yr. old car. Maybe with some roller rockers and a power adder, I'll keep fending them off for another 11 years...

 

[Makara]

Smaller images would be nice

 

[plumcrazy]

great numbers and especially from those mods id think

 

[throttle]

I saw your car on the whiteboard down there, and there were some awesome cars. My friend was just knocking Vipers the whole night and bragging about the supra. They're nice but they're definately not overrated like he said. I wish i woulda gotten off work earlier to see your car run, but hopefully next time i can.

BTW, nice numbers!

 

[99 R/T 10]

No, not great numbers, and part of the problem is you're getting way lean. First thing I would do is disconnect the computer for 10 minutes. Reset it basically, it should run richer.
What kind of gas were you using? 91 Octane? Get some booster next time. I would do a back to back on the reset and see what happens. My 96 with similar mods pulled a 394 HP and 485 TQ. Your HP is down due to the lean condition.

 

[HOdbleFman]

There has to be something wrong with the data. You're power kept rising steadily even after the car went lean. If it was as lean as the a/f graph shows (leaner than 18:1), you wouldn't have made that much power. I'm no expert, but I'd say it would run like crap if it got that lean. You'd hear more than a little pinging.

 

[obaa996]

Sorry about the pic sizes. I don't have any s/w at home to do resizing, and just wanted to get the graph up. I'll try to do it when I get in the office tomorrow.

I actually had to leave early, as my kids were with the babysitter. The people at Torquefreaks were really cool, and able to get me in/out in about 30 mins.

I'm curious why you say the numbers aren't good? My hp looks to be about 15-20 higher, and torque is very similar. What's the best way to disconnect the computer? Is there some fuse I can pull, or do I need to disconnect the battery at the rear wheel? Does the manner in which you drive the car affect how it "learns"? I babied the car after the rebuild (for break-in); the battery hasn't been disconnected since. I'd still think that something else is not right though, since the a/f ratio basically goes haywire right at 4k, like it hits a wall.
BTW, yes; I was running 91 octane (Chevron). It doesn't get any better than that in OR, plus (minus, actually) the gas is oxygenated. Still, the a/f issue should be more linear if it was a gas issue?

During the first run, they thought that perhaps the probe got spit out of the pipe, but for the second run, the probe was clamped to the tip. The results were consistent for both runs, and other cars on there had reasonable looking graphs, so that's why I'm leaning towards a car issue. Hopefully, this is something my tech can figure out....

Thanks for the thoughts; I'll keep you posted on what they find out.

 

[Tom F&L GoR]

Here you go. My '94 is very similar except no headers and made 404RWHP/487RWTQ.

 

[99 R/T 10]

Sorry about the pic sizes. I don't have any s/w at home to do resizing, and just wanted to get the graph up. I'll try to do it when I get in the office tomorrow.

I actually had to leave early, as my kids were with the babysitter. The people at Torquefreaks were really cool, and able to get me in/out in about 30 mins.

I'm curious why you say the numbers aren't good? My hp looks to be about 15-20 higher, and torque is very similar. What's the best way to disconnect the computer? Is there some fuse I can pull, or do I need to disconnect the battery at the rear wheel? Does the manner in which you drive the car affect how it "learns"? I babied the car after the rebuild (for break-in); the battery hasn't been disconnected since. I'd still think that something else is not right though, since the a/f ratio basically goes haywire right at 4k, like it hits a wall.
BTW, yes; I was running 91 octane (Chevron). It doesn't get any better than that in OR, plus (minus, actually) the gas is oxygenated. Still, the a/f issue should be more linear if it was a gas issue?

During the first run, they thought that perhaps the probe got spit out of the pipe, but for the second run, the probe was clamped to the tip. The results were consistent for both runs, and other cars on there had reasonable looking graphs, so that's why I'm leaning towards a car issue. Hopefully, this is something my tech can figure out....

Thanks for the thoughts; I'll keep you posted on what they find out.

You can disconnect the computer at the source. The computer is located on the right rear side of the engine compartment. Just unhook the three(3) connection and let it sit for 10 minutes. I think you can also unbolt the red battery wire on the left side of the engine compartment, but I had to do this on mine a couple of times and always did it at the computer. Let us know how it works out. I bet you'll pick up 20-30HP. The biggest concern is that the car is leaning way out. You might want to conside a Roe Racing Vec 1 to modify it for safety and better performance

 

[STUGOTS]

Glad to see you OWNED the vette with an 11 year old car congrads.

BTW get yourself a vec 2 and have it fine tuned and that kean will just go away.

 

[Newport Viper]

411 and 486 here. S&B, Tubes Roe, Cat back.