Thread: NX2000 SR20DE SR16 pistions Jim wolf technology C3s, ecu

Nice Mac!!!!!!!!!!

dyno sheets up



its still the same set up basicly, im not sure if its the actual sunbelt motor but its the one thats been in the car for a long time. but the cams that were in it were actually smaller. ive been talking to jim wolf about an optimised cam for it. after about 6.5k it starts to get vacuum the head cant flow for the rpm the c3 cams. the cams i pulled out of the motor when we got it from renan were similar to s3s but slightly bigger and more duration. id love number like that but unfortunetly we cant have over 175hp cause we are running in a class thats power to wieght ratio haha. im hoping to get a new cam with better low end but the car is so light you cant really tell its only 132tq

but i feel 170whp on pistons and cams are still pretty good.

yeah that is very good.

de's still have alot of potenial in the right hands.

stratton.

I really like that setup. Especially the weight.

Ah, that's right, Renan was who bought it from us.... and you bought it from him? I know what my cars feels like at 2300 with the power I have and I can't imagine a little more power and way less weight! Must be a blast on track! Power to weight classes suck, but are fun if you are a very good driver!

Car looks great, keep it that way!

Looks like a stingy dyno to me, only showing 132 ftlbs for a high compression DE. The engine would probably make more on another dyno.



Mac, how would the organizer police the power to weight class if each dyno read differently?

To me, it would benefit the racer to dyno on a low reading dyno and submit it the steward.

Nice car man!!! I would love to hear that car giving some battle in the track!!!

What cams are you going to try? S4? S5? C2?




I think that would be done by measuring the car's power all in the same dyno, so they have the same gain/drop in power for the dyno results... its what make sense to me...

Torque on an engine like this can be dialed in or out with cam settings.

When I dyno'd mine, we were able to get between 133 and 144 wtq with different cam settings. The lesser torque made more HP higher in the rev band, but the more torque made slightly less power and peaked lower, but had a much wider powerband! I chose less hp and wider powerband.

I'm guessing with a power/weight restricted class you'd want as much torque and as wide a powerband as possible. I'm sure you've got cam gears. How much playing around did you do? I know it's a royal pain on SR's but really pays off when you get it right!

Yes exactly what ivanorcan said. since the series is only westcoast there is a central dyno all the cars have to be tested at.



yes i got the car after renan he switched to the honda challenge and ditched the nx. when we ran an event with the honda challenge guys they were upset the nx was faster then them even though its in a different class. haha

i havent played with it yet since we cant get the airflow through the head. once i find a cam that will allow the head to breath then i will be adjusting cam timing to fine tune the power band. it has a very nice power band t the moment but it can be better. we are taking it to the track this week end and ill post the videos up when we get back.

You may find the air flow issues go away with cam adjustments. Changing the overlap may solve that issue. I know that having the exhaust open too early would cause some vacuum scavenging as the exhaust rushes out too early.

Mike K wrote a whole bunch of stuff about how this all works and I won't try to paraphrase him as I'll probably get it wrong. It seems like most cars like some intake advance and some exhaust retard to make the best powerband.

My car is +2.5/-2.5 (10.5:1 with C2's) That setting made the fattest powerband after tuning versus 0/0 after tuning. I think if I adjusted them even more I would gain some more top end, but I'm already having traction issues in the dirt as it is, so I'm happy with where things are.

At any rate, I'd go drive it and have a blast! You may find that it's plenty of power for the class anyway, regardless of the potential maximum you could make.