RB25 Neo, Drifting, getting response up

[Lopin18]

So im trying to refresh my setup to get more response, torque, this is purely a drift car, but i cant seem to decide what would work out to achieve my goals.... I was planning to get tomei cams, 260 9.15mm, but as far as ive seen the stock ones give a better low end/mid torque setup, springs and retainers ill hold it off for now since i dont wanna rev more, i want low end torque.... exhaust manifold ive been reading that the stock one being a log style, would give better spool.... only thing that comes to mind right now is a standalone ecu and switch from 100 octane to VP fuels 109 octane or VP 113 with lead and give it more timing.... maybe even switch the headgasket to a thinner one to get 10.5:1 CR

 

What are the options for these engines to improve it torque wise and in the low rpm range?

 

RB25 Neo specs:

-Rb26 Crank, CP 26 Pistons, Eagle rods

-RB25 Neo head, quench pads removed, 2.5mm cometic HG, compression ratio is around 9.5:1

-Stock exhaust manifold, Godspeed intake manifold

-Holset HE351 turbo

-550cc rx7 injectors

-Z32 ecu, chipped

-Oil control mods, crank collar, jun oil pump, restrictors etc etc.

 

Last time i broke the exhaust poncam installing it so im back to stock cams. But now im stumped. i dont know whats the best plan, budget is not very big and the turbo selection was made because i can easily repair and replace that turbine without hazzle (im in a Caribbean island), thats the dyno sheet, its pretty close to my last dyno on a stock rb25 neo, before mixing the rb26 forged parts. Compression ratio stayed pretty much the same so i guess thats why. (Stock is 9.5 i think right?) and i had 450hp @ 23psi before, so im pretty much in the same position as before.

That was last friday, i broke the clutch on sunday, it was slipping so i think thats why the dyno sheet has a weird peak in 2 places. speed remained constant so thats why we ignored that we had a clutch problem but it was definitely slipping on the track @ WOT

Edited May 14, 2018 by Lopin18

[Kinkstaah]

All of that will have tiny, marginal gains.

Want response?

Change the turbo or change displacement. (i.e 3L but availability could be hard there!)

They are by far the best, easiest ways of getting response and in the real world also the most cost effective.

[GTSBoy]

+ supercharger.  Nice big Whipple.

[discopotato03]

I'd be putting the standard RB25DET Neo inlet manifold back on it . The runners are reasonably long and Nissan downsized them compared to the R33 spec inlet manifold obviously to increase air speed into the inlet ports .

A lot of people seem to think that fitting the short runner ie Freddy etc style inlet manifolds to any RB25 costs it torque and throttle response in the lower to mid range .

 

[r33cruiser]

Strap on gt35, E85, 35ps....get bitches!

 

In all seriousness, is response that crucial? I haven't seen  drifters sitting on 3,000rpm around a track.

 

 

[hypergear]

I assume you are running external gate. I have a recent case of a turbocharger that we've built, that pulled over 530rwhp E85 ( similar to pump 105) @21psi full boost by 4000RPM out of a stock R33 Rb25det.  With an Neo head and slightly larger capacity you should see even better response. details of the build is at:

https://www.sau.com.au/forums/topic/261613-hypergear-turbochargers-and-high-flow-services-development-thread/?page=604 

[Lopin18]

Taking lots of notes lol. 

Thing with response is that im running Achilles 123s and similar grippy tires and it would be better for me to get a better torque curve down there.(our track layout keeps giving me a hard time when i have to get the power back up to spin those tires after they heat up, they are insanely grippy and i have to keep up with the high budget setups here) Right now i have low torque on low end, clearly due to the turbo selection as far as im seeing now after watching responses and dyno sheets from setups used around here. 

AHh that damn dyno sheet didnt have the torque line, ill try to get it. 

 

Now diving into that huge thread from hypergear.

 

Edited May 16, 2018 by Lopin18

[KiwiRS4T]

Couldn't really read your chart anyway.  To get low down torque on my heavy Stagea I got a GT3582  .63 a/r and as you can see from my charts it worked much as planned (although top end was limited). This was on an RB30 but could work on your car too.