Chevy406

iTrader: (12)

Several weeks ago I finally got my tune about where I was comfortable enough to put the car on a dyno. I took advantage of a "Dyno Day" at Henson Performance in Birmingham, AL to make a few pulls. I was suprised at the 471whp / 470 tq and chalked it up to a "happy dyno". Today I stopped by another local dyno to make some back-up runs just to see how far off the first test was. After a small fuel adjustment I had a 467whp / 461 tq (SAE correction of 5%) printout, pretty much identical between the dynos. I believe both of the dynos are Dynocom, with the one today being a 3,200lb roller with eddy brake.

I understand the concept of simply using a dyno as a testing tool, and not to get too concerned with the numbers, but I would like to just hear some comments about how Dynocom numbers compare to other well known dynos.

My car is a '99 FRC with stock LS1 shortblock, AFR205 heads, YT rockers, Comp 224°/230° XFI lobe on 111°, headers with Ti exhast, U/D pulley, FAST 78mm & stock TB ported by me, 30# injectors, Textralia clutch, stock driveline. HP Tuned by me.

I have a couple 1/8 mile passes with 94.2 mph but poor 1.9 sixty foot and sorry 7.70 ET.

So, what's the consensus: Just use the test as a tool to tweak my street tune or are these results in line with other dynos.

venom ws7

iTrader: (13)

Very nice Congrats the numbers are very believeble.

What the compression of the engine??

Nitroused383

iTrader: (10)

I would say the torque reading is higher than it should be.

Chevy406

iTrader: (12)

Yeah - the torque numbers are too high for a naturally aspirated 346" LS1.

I calculated my static compression a little over 11:1 (using 59cc chambers) and my dynamic compression was around 8.8:1. I can get by with 27° of timing at WOT on 93 octane, but I start to pick up a little knock above 28°. I might also add that this stock short block has 179,000 miles on it too. It should be broken in by now.

allngn_c5

iTrader: (3)

Nice results, especially considering you got 179,000 miles on the block. What was the mileage when you started modding ?

blu byu EH

iTrader: (25)

Hey these are my old heads. Congrads man.

Chevy406

iTrader: (12)

Yes they are - you did me right on that sale last year.

I bought this car 2½ years ago bone stock with 115k miles. It got headers within the first 10k miles, the first cam at 128k, and the AFR heads and current cam at ~ 155k. After a couple clutch smoking launches last fall, I put a Textralia clutch in it in Feb, and then broke the output shaft in April at the dragstrip. Although I upgraded to a hardened shaft, I haven't tried to launch it with sticky tires again. Maybe, just maybe I'll have to borrow some tires to see if I can get a decent 60' and ET out of it. Meanwhile I just continue to drive it 500+ miles a week back and forth to work.

I am still just a little skeptical about the dyno numbers though. I may try a Dynojet just as a comparison.

Slowhawk

iTrader: (12)

Very nice,expecially for the mileage.

On the Dyno,Dynocoms are known for reading higher torque #'s than the other dyno's.I would expect 440hp/410tq on a different brand dyno which is still very good.

performinnorman

iTrader: (7)

Great numbers.

Chevy406

iTrader: (12)

Thanks for the feedback. That is the kind of numbers I was expecting also. A wise man once said "there is nothing new under the sun", and that saying is certainly true in the LS1 world.

matt1289

I thought my torque was a little high too but I haven't had the time or money to throw it on another dyno to see.

Nitroused383

iTrader: (10)

Wow that would make me go insane driving that much for work. Why do you have to drive so far to work?

RJB01camaross

The torque is a little high but great numbers!!!

Chevy406

iTrader: (12)

Maybe I should move a little closer? The crazy part is I have been driving the same commute for 13½ years now. My '94 Silverado has 326k miles and the Corvette has 179k. But the traffic is typically light, and I can make it in 50 minutes each way.

zx9rgreen

iTrader: (18)

Post up your findings if you find a Dynojet. I'd like to know the difference as well since I was on the dyno after you. How's that TT 408 coming BTW?

Chevy406

iTrader: (12)

I was about to ask which car you have and then I noticed your sig. I love your Sonoma build. Very nicely done, great stance and sounds wicked.

The turbo 408 build for my Nova is going to be a long range project. I have picked up the rotating assembly, and am about ready to cart the block off to the machine shop. But every time I start adding up parts remaining to buy, I get a little depressed. All in good time I guess. Hanging around a bunch of forced induction guys at Lane's dyno Saturday got me pumped up to get my build moving along.

ScreaminRedZ

iTrader: (3)

Solid numbers. Let us know how it does when you get some traction at the track!

zx9rgreen

iTrader: (18)

Thanks for the kind words about the truck, it's no FRC but will suffice until I can pick a vette up. BTW, How much did you pick up the higher mileage FRC for? Have you started a build thread with the 408? Ever decide on a set of heads? We can take this to PM if you like.

Chevy406

iTrader: (12)

I bought my '99 FRC off Ebay back in March 2007. I paid $15,500 for it with 115k miles. I have seen better sounding deals since then, but from January 07 to March 07 that was the best I could find.
I have a Nova 408 build thread on the HSVracing forum, but I thought I would wait a little to get more progress before submitting myself to the scrutiny of this forum. It's a tough crowd here on LS1tech.com. I am still undecided on heads. Of course budget is holding me back from snatching some new off the shelf. If I can find a deal on some gently used aftermarket heads I would love to go that route. Otherwise I will have my 317s CNC ported and cut for 2.08"/1.60" valves.