I went and got a local tune at the closest ls dyntuning shop. He said it was a dynacom eddiebrake dyno. I read these are dynoqueen dynos but does this graph look strange. The injectors are at 96% duty cycle at 6000rpm. On the dyno only went to 140mph so thats all i have a graph for but did use a wide band in the exhaust to tune it to 6k. We both insisted keep the transmission shifts stock all at 6k and stock rev limiter i think as he ran it on dyno first to see where the powerband was. Does this look right and how to translate it to dynojet or mustang dyno numbers. At 40mph the stock size hankooks go sideways with the traction control on so would need some et streets and the local track. He told me the afr was at 12.7 took 2 hours and after having it WOT the power steering was fully functional when i got the car back from him doing a couple street trips. The car is all stock with factory 3.15 gears, tsp headers, volant air filter and 1839 220/224 cam. Said he didnt lock the tune and would recalibrate it for a gear swap or even tb if i did swap. He did have one of the black sheetmetal intakes short height said it added 20hp and fit under the corvette cowl but would need an ls3 drive by wire throttle body i think is the only option there.

 

 

I dont think we could find where you can raise the "2mph" fuel cut to "250mph" in the parameters of the vats if anyone could point me in the right direction for this. We raised the speed limiter to "250"mph the tuner showed me on the laptop where you could adjust this but told me he just turned off the vats which should disable the fuel cut issue. I also got the rear o2s and air pump codes turned off so no SERVICE ENGINE SOON light but i do have a "service vehicle soon" and "stms" message on the digital read out. Would need new wheel sensors for a tech 2 to turn the stms display off. Any idea what the service vehicle soon is for other codes stored in the pcm non engine related or even the stms?

 

Weirdest dyno graph I’ve ever seen. No rpm?
What gear did he use?
I ran a similar dual roller dyno for 5 years. It was a Dyno Dynamics. It looked quite similar to the one you used.

Attached is what a normal dyno curve looks like. From my C5


Also an Eddy Current dyno.

What he gave you just looks bizarre.

Ron

 

Yes i bet hopefully on security he didnt give me some strange tune. Told me will throw it on dyno with tune uploaded and see where it makes power then see if shiftpoints need to be raised. Im not sure he said the graph he gave me only went up to 5500 for 140mph didn't want to take it above 140mph on the dyno but the rpm says 5950 rpm 96% injector duty cycle. He said it was dynocom 5000 eddybrake dyno. He assured me it was 12.6-12.7 afr WOT and a safe tune ready for 1/4 mile track. Do you think 25 degrees is enough timing? Told me he left the shiftpoints at 6k thru all the gears. Another tuner on hptunerforum told me it looked lean because the power drops. I dont have a wideband to see for myself. Two other shops that use a dynojet one asked if i wasnt happy with the tune and said the graph didnt look right. Said i could make pulls with AFR logging for 150$ on their dynojet that usually steadily inclines 6000rpm-6500rpm before it drops off. It was lsx performance 360 here in san antonio closest to where im staying besides nelson performance which doesnt have a dyno anymore. Lethal performance was booked for a week and lunatic garage said i had to drop the car off would take a day witht he car at the shop to tune but would let me do some pulls with afr logging on their dynojet for 150$ to see what the problem is after having it tuned at this other lsx tuning shop. Where i went the tuner didn't say there was any problems with the graph other then it peaks here so we left shifts at 6k. Its similar to my 98 z28 except open hooker headers and what sounded like a smaller 218 cam 6 speed 3.42s made 375whp 375wtq. These are from 2011 98 z28 with a small bullet cam, hooker headers, manley dual springs. I could tell it was 375whp as it did 114-116mph 1/4 mile traps. The other overlay is from late 2011 when i put an s475 on the same cam stock longblock 6lbs. Dont want to damage the cammed corvette engine from a bad tune. Fuel injection specialties was also booked way out as well as henderson performance i think.