Got my lude tuned last weekend, pretty happy with the results:



8.5psi on an RB25 T3 (or T28 as some people might call it)
-Internal wastegate
2.5" downpipe and straight-through exhaust with high-flow cat
DRAG manifold
Tial BOV
2.5" intercooler piping
26x3x7 intercooler
RC 440cc injectors
S2000 throttle body
Hondata IM gasket

As you can see, it only really holds power to ~6500 which I'm ok with; this is an autocross car so it needs a lot of mid-range torque

However, my main concern is that big dip in power at the vtec crossover. On the dyno we tried moving vtec around but all it did was move the dip. Jei said that it was probably a combination of the manifold design and the cat that's causing a lot of backpressure when it switches over to high cam. We left vtec at the point where it gave the best overall torque curve

Now I'm trying to plan out my next move, which I'm thinking would be a different manifold. I want to keep my AC so my options are limited to "log-style" manifolds mainly, but I have given some thought to Spoolin's Quick-4 AC manifold. I'll probably pull the trigger on that once I get some $$ saved up.

Anyways, what are your thoughts on the curve, why it has that dip, and what my next move should be?

 

Nothing? hmmm...

 

what clutch you running? just got tuned yesterday and my graph dipped right before vtec just like yours rockin the log as well

 

oops, forgot to mention that, It's a Competition Clutch Stage 4, no slipping

 

cool, i thought it would make more power.

 

Thats pretty sad for a turbo h22. Get a larger turbo on there.

 

Get a bigger turbo, those tiny t3 are tiny.

Must be fun car, get a video.

 

Autocross car, doesnt need a ton of peak power. I'd like to see someone make 200ftlbs naturally aspirated for the money I spent on this setup. It's a purpose-built car, not a highway monster

I went small so I could get a lot of mid-range power with minimal lag

And yes, it is a VERY fun car haha

So no one has any other ideas as to that big dip? Or is it definitely the manifold?

 

you need a 3" exhaust bad. even stock n/a preludes make the most power on a 3" exhaust...

 

if you are happy with the turbo, I would go with a larger exhaust... that might help out the decrease in power over the rpm range....

Although, given that it is an auto cross car, will you really be revving it that high? Maybe something to consider...

 

My h22 turbo setup saw gains and a smoother powerband when we started adjusting my aem cam gears. We didn't go that far but a few degrees on each cam helped.

 

Actually now that you mention it, when we were trying to figure this out he asked if I had adjustable cam gears...so I bet that would help a little bit