I put my '02 Z back on the dyno this morning to get a 2nd opinion on my previous numbers. I had received quite a bit of negative feedback on a reply I made in the below thread with my dyno results and I wanted a second opinion to verify the accuracy of my previous results.

http://forums.corvetteforum.com/c5-z...-the-dyno.html

There was enough logic behind some of the comments in that thread that I began to believe that the numbers were not correct. With nothing more than bolt-ons I had laid down 411 rwhp and 408 lbs/ft torque.

My previous dyno sheet.



This morning, I took my car to a local shop that actually specializes in import tuning. They also happen to have a really nice dyno facility. I brought my previous dyno sheets in and got a quick rundown on the differences between dyno machines. Apparently the Dynomite machine that I had gotten my previous numbers from was of the variety that does not place a load upon the rear wheels during the dyno pull. No load on the wheels equals higher numbers. The dyno at the shop today is of the variety that does place a load upon the rear wheels. Because their dyno placed a load on the wheels I was told that I would probably not make similar numbers. I said ok and prepared myself to be disappointed.

Well, I was not disappointed. The car laid down 420 rwhp and 414 lbs/ft torque this morning. The only mods that I'm aware of on the car are a Hurricane CAI, FAST Intake, 178 degree thermostat, clutch and flywheel, LG Long Tubes and x-pipe, and Borla Stinger exhaust. The previous owner had done some tuning on the car and I also had it dyno tuned back in April.

I'll probably get lots of comments again, but here's the latest dyno sheet.



My car on the dyno.

 

those seem like realistic numbers to me for your mods and a very good tune.

 

Those are great numbers. I know what you mean about posting HP numbers. I posted mine and was really beat up over on the LS1Tech site. That's a really good torque number, you should be thrilled. Enjoy the power!

 

Not going to argue about dyno numbers, although it is curious that the mustang dyno read lower than the dyno dynamic, it's usually the other way around. If you had some 1/4 mile times it would be more meaningful. I read through that other thread and that time slip (the 128 MPH trap speed) indicates your car had a lot more mods than simple bolt ons at the time and was definitely doing more than 420 rwhp. Based on torque measurements, I'd say it's not a stock cubes motor.

 

Those are phenomenal numbers, any way you slice it. My initial thought was that you have a cam and just don't know it, but even still, I don't know of any cam-only setups making those torque numbers. Shaved heads, maybe? It doesn't matter...

As Paul said, enjoy the power!

 

Yes a cam only car can put down those numbers. Mine is at 411/380 I will add though, his car nor mine is a cam "only" build. The headers, CAI and other supporting mods make that clear. The engine in the OP's ca r is almost sure to have a custom cam installed, or maybe some head work done... IDk, but those nubers support there being something other than whats in the mod list.

 

My dyno guy said he can get those numbers out of a Z06 with exhaust, intake and a tune.
If your not a Z06 then... it is different story.

Its all about how good the tuner is. He seems to have gotten me 30 more hp then most A&A kits.

I would not assume that car has a bored engine because of an extra 20 hp.
I think you have a nice running, well tuned car. You have
two dyno sheets to prove it. Just be happy, worry about if the car was bored
or had head work when she need an overhaul.

 

Congrats on the great numbers! I'm jealous. Enjoy!!

 

"cam only" in this usage simple means no work done to the heads or intake manifold (and of course no power adders or displacement bumps). Bolt-ons are implied. I'm definitely not the only one using this lingo.

414 ft-lbs is not easily attained for a cam-only C5 Z06.

 

Just wanted to be sure we were all on the same page. And I agree, 414 is alot of torque for even a moderately cammed LS6.

 

That's about right..neighbor down the street has a 2002 Z .And he put down 400 HP just with CAI and 1 7/8 ARH headers and tune. On a dyno dynamics. So u with a fast. Making 420 is right on the money...same dyno my 2010 ZO6 made 448. People just don't realize that the lS6 is heavily chocked off from the factory. Air box and cat's vs ls3/ls7's

 

Not

Something in the motor is not stock. Boltons don't equal 420whp

 

The only way to verify numbers is the drag strip--when you pick up your time slip==either et or mph tells the story--dyno is nothing until they can drive your car thru the qtr. mile on a dyno--

 

But they already can...

 

The previous owner slipped a mild cam in there...no biggie...enjoy the power.

My mildly cammed Z16 does 421/400 with just a Halltech CAI, Kooks catted LTs and an UD pulley.

 

My guess would be that it is cammed. Just dyno'd my '03Z and put down 425rwhp. Cam, longtubes, CAI, B&B catback.

Either way, who cares. Great numbers. Enjoy.

 

Gotta be a cam.

Congratulations!

 

OP has a FAST intake AND a lightweight clutch assembly. Everybody seems to be forgetting that when they post up their own cam only numbers with stock intake and stock heavy clutches. With stock exhaust, the FAST is good for 15whp which puts the OP at or over 400whp (notwithstanding the additional gains realized by the FAST with headers) before the clutch which is at least 10whp by itself. If we all agree that 385whp is reasonable before those 2 then the numbers don't seem all that unrealistic for a stock cammed engine. All these cammed numbers have torque lower than hp, whereas the OP's torque is pretty much there with the hp. I'm just sayin'. . . this is how I'd been planning to mod my car anyway, I'm glad to see the numbers are there.

 

I mostly agree with this sentiment. However, I'm still thrown by the OP's high torque readings. Even if he was making 385 ft-lbs with just bolt-ons (which is already on the high side), I don't see a FAST and streetable clutch getting him to 410+ ft-lbs. Thoughts?

 

I hope the OP understands that none of us are attacking him or his car. We're just trying to understand how he put down these numbers.

Hell, if he really did get here with just bolt-ons, FAST, and lightweight clutch... then sign me up for a FAST and clutch job!