Josh@PremierAutosports

iTrader: (11)

My car dynoed at 506-509whp on 150, 200, 250 shot. Whp and TQ stays flat from 4700-6400. I've tried different AF and different timing and it changes very little. At first I thought it was the TCI Ultimate Street Fighter 3700 only being able to hold that much power but recently I have been thinking it could been the cam. My cam is Comp 232/234 .595/.598 112lsa. The Comp part number is 54-446-11. I have a 370, Absolute Speed stage 2 heads, Th400, LS6 manifold. Any guesses?

Thanks

383LQ4SS

iTrader: (33)

I cant see why you would have NO increase when going from a 150 to a 250 due to cam. Even if it wasnt an efficient nitrous cam I would expect atleast 60% gains on those increases.

I have spray a 100/200/300 on a similar cam (MTI R1) in a 383 thru a t56 and saw good gains from each step.

Id either look at the converter or the the kit. Maybe call TCI and see what they think?

My guess would be the converter also.

Big Geek

iTrader: (2)

The trick of it is most likely in the fact that you are running an automatic tranny. If I had to guess I would say that the 250 shot is flashing the convertor a a good bit higher and that is why you are not seeing an increase on the dyno. I would be willing to bet that it is in fact making more HP and TQ but the convertor is playing tricks with the chassis dyno. The way to tell for sure is to get it to the track and see what your MPH looks like. I am willing to bet that there will be a difference.

Now on another note there comes a time when a given displacement can only ingest so much N20 but I seriously doubt that an LS1 with a 250 shot is at that point. Hope this helps.

Jim C.

Josh@PremierAutosports

iTrader: (11)

I called TCI and they brought up the cam but said to send in the converter and they would check it. The car picks up 1.5-2mph per 50 shot increase.

Big Geek

iTrader: (2)

I don't think anything is wrong with the convertor but more so that being an auto with a fairly high stall it is just playing tricks with the dyno. The stall speed is not necessarily going to flash the same with a 250-shot as it does with a 150-shot. By hitting the motor with more N20 it is most likely flashing the convertor higher and allowing for more slippage. This would make the dyno readings appear low. It is not an uncommon issue. The MPH should be telling you the truth.

Jim C.

GrannySShifting

iTrader: (10)

Most likely blowing through the converter. The average "na" cam will still make the power in the midrange but it wont blow down the cylinder as effectively up top.

Big Geek

iTrader: (2)

If you get the chance and are not doing so already the next time you call TCI try Kevin Winstead. He is an engineer there and all around good guy, plus if I am not mistaken he still lurks around here. He has helped me out on several convertor related issues. Good luck to you and I hope you resolve it quickly. Take care.

Jim C.

hc_performance

iTrader: (4)

Yeah Kevin is a great guy. I'm about a hour away from TCI and I used to test there fwd honda axles for him.