Dynamometer Results & Comparisons - Pitiful dyno results

Just got back from SE Turbo performance in Dallas, GA (the owner, Paul, is a super nice guy and I highly recommend them) to baseline the LS1 RX7 I picked up and it was disappointing. I'm pretty sure it's a stock '98 F-Body LS1/M6 and it put down 248hp/263tq. From everyone else's I've read, ~300+ is common in stock form. It runs great, no hesitation or anything outwardly wrong as far as I can tell. It's just such a huge drop that I'm not sure where to start looking since nothing seems out of place. Anyone else had similar results?

Those results sound like a mean v6...not ls1

That's horrible.

Is it firing on all cylinders? Should easily be 280-310hp and over 300 TQ.

It's also a 98 so it will be down on power over an 01 because of the heads, intake and manifolds. Also what is the exhaust and intake setup? And how are the plugs?

Even a 1998 LS1 should make at least 280rwhp...its not that much worse than the 01-02 cars...

Did you happen to ask what other stock LS1s make on that dyno? What kind of dyno was it? What kind of correction factor? What conditions? Those are just some starters...

Did you happen to ask what other stock LS1s make on that dyno? What kind of dyno was it? What kind of correction factor? What conditions? Those are just some starters...

Dynojet, 22% humidity, 62F ambient, SAE 0.99

It's a shop that specializes in GNs and Mustangs, so I didn't think to ask him about others. It's not missing on any cylinders, very smooth acceleration with a sweet exhaust note. I'm going to pull the plugs this week while I'm off. Bought the car as a 90% complete project so I'm still working on it. Need to wire up the OBDII port next.

My 98 auto stock dyno'd over 300 so somethings up. Go checkout another dyno and see if there is a difference, i know a few in Tampa.

With RX7's you have to watch how the intake is setup and also the exhaust system. Done wrong and it will drop alot of power. Sounds like you haven't had it scanned or tuned yet either.

With RX7's you have to watch how the intake is setup and also the exhaust system. Done wrong and it will drop alot of power. Sounds like you haven't had it scanned or tuned yet either.

Scanned, no, but being stock it shouldn't really need any tuning, should it?

Dynojet, 22% humidity, 62F ambient, SAE 0.99

It's a shop that specializes in GNs and Mustangs, so I didn't think to ask him about others. It's not missing on any cylinders, very smooth acceleration with a sweet exhaust note. I'm going to pull the plugs this week while I'm off. Bought the car as a 90% complete project so I'm still working on it. Need to wire up the OBDII port next.

Ok, starting to sound like maybe it is the car and not the dyno but, we are not there yet. Can you hit up a track and see what the trap speed and race weight are?

Also, how about a sheet? If the curve looks normal and then takes a shit we could point more towards the car as well.

Ok, starting to sound like maybe it is the car and not the dyno but, we are not there yet. Can you hit up a track and see what the trap speed and race weight are?

Also, how about a sheet? If the curve looks normal and then takes a shit we could point more towards the car as well.


I wish I could get it to a track, only have a finite amount of time in the states before I drop it off for shipping to Spain. Here's a pic of the data print out, don't have access to a scanner at the moment.

http://i40.tinypic.com/aujgjo.jpg

http://i41.tinypic.com/28up4ls.jpg

Looks like some operator error on that dyno sheet. What gear did they dyno the car in?

Looks like some operator error on that dyno sheet. What gear did they dyno the car in?

He had me do it in third. This was the first dyno run I've ever done. Was this wrong?

Also, what made you say operator error? Genuinely interested!

4th gear because it is 1:1 is the correct gear to make a dyno pull in.

4th gear because it is 1:1 is the correct gear to make a dyno pull in.


Well, that stinks. Live and learn, I guess. I'll have to re-run it to get accurate numbers.

He had me do it in third. This was the first dyno run I've ever done. Was this wrong?

Also, what made you say operator error? Genuinely interested!

Yep, as stated you should use 1:1 gear. A dynojet will show a fairly significant lower power in lower gears.

The red line made me say operator error. Engine wasn't at WOT for a while during recording of the run. Maybe more just rookie mistake than operator error. At least you will know next time. :)

I cant imagine a dyno shop that lets its customers do their own dyno pulls... If for nothing other than this reason alone.

I cant imagine a dyno shop that lets its customers do their own dyno pulls... If for nothing other than this reason alone.

I was thinking the same thing...

Lowest LS1 dyno ive seen bone stock convertible pewter and i still remember it to this day and this was several years ago to say the least and it dynoed 274rwhp and highest ive seen was a silver WS6 M6 331rwhp. So definitly something wrong with the dyno shop there because it should not be dynoed in 3rd gear, shouldve been 4th. I have dynoed my car in 3rd gear though and definitly did not make a huge drop in power at all if i can remember it was 9-11rwhp drop compared to 4th. So dont know whats going on but thats just my experience.

You have to get that OBD2 port wired up ASAP, it's the whole key to letting you know what's going on with the engine. In the meantime I would check the plugs while you do compression/leak down tests. Also make sure the throttle body is opening all the way under WOT.

Seeing how the dyno run was done in the wrong gear, the results are basically pointless to compare to anyone else.

Go get it done in the right gear and then we can say whether your engine is running right or not.

I cant imagine a dyno shop that lets its customers do their own dyno pulls... If for nothing other than this reason alone.

I won't use a shop that doesn't let me run my own car.

Where are you experts getting this information from regarding dyno results being significantly different if you aren't in a 1:1 gear? It will make a very negligable difference running on a dyno in a any other gear. Think about it this way... when was the last time you heard of someone dynoing significantly higher with 4.10 gears versus 3.42's or visa versa? That's pretty much the same thing as having the car in a different gear. There will be very small differences due to friction, etc. but we are talking in the 1-2% range... nothing near what the OP is experiencing.

When i ran my GTO on a Mustang dyno, i did 3rd and 4th gear. The difference was 432/440hp it makes a very small difference.