R34 tuning

blackvr · Post by **blackvr** » Sun Sep 14, 2008 8:51 pm

ok.....

Legionnaire · Post by **Legionnaire** » Sat Oct 18, 2008 9:59 am

Hi, guys! I decided to revive this thread

blackvr,
I'm going to tune a neo 25 with 3071 on it soon, so i'm interested in updates and results from other GT30 users on RB25s. How is that neo with GT30 doing?

Matt - are there any updates on NVCS switching point on r34? Injector latencies? Really interested

As for stock RB25 turbos being no good - well, R34 are slightly better, but overall they are not "no good", they are fragile. Any boost increase over stock is lottery where you can lose turbine wheel.
But compressor is very nice 67mm unit that can flow ~40lb/min worth of air @1.2 bar.
On a rebuilt stock turbo (stock compressor, stock housings, new cartridge from garrett, T25 53mm steel turbine wheel) we made around 202rwkw at 0.8bar (12psi, i guess? I'm more used to metric values). Stock exhaust was the obvious restriction.

Cheers, Petros.

PL · Post by PL » Sat Oct 18, 2008 10:50 am

Hey Petros,

I don't do much work on RB's but there was an R33 at the dyno place yesterday where I tune. They were running it up while I was there and they said the same about the turbos - they are fragile and they don't seem to respond well to higher boost anyway.

They reckon you're best off to just do a small boost increase and optimise AFR's and timing to get the power. This one was making 208rwkw on a Dyno Dynamics dyno on around 11psi. I thought this was quite a decent figure for a standard turbo. Only other mods were FMIC and free flowing exhaust.

My brother has just bought an R34 so I guess I'll be playing with that shortly - so I'll be keeping a close eye on this thread! I've insisted he fit a FMIC before we do any tuning. I think it's got a decent exhaust system already.

PL

Matt · Post by **Matt** » Sat Oct 18, 2008 7:54 pm

I'm looking for an R34 also.... speedlab has found the latency for these but I'm still to chase up the limiters when I get a free moment

Just got my new car on the road this week so hopefully that will free up some more time (when I'm not fixing up the body on it...)

blackvr · Post by **blackvr** » Thu Oct 23, 2008 12:55 pm

[quote="Legionnaire"]Hi, guys! I decided to revive this thread

blackvr,
I'm going to tune a neo 25 with 3071 on it soon, so i'm interested in updates and results from other GT30 users on RB25s. How is that neo with GT30 doing?

The customer was happy with the top end power, but not so happy with the laggier turbo response. To brighten up the lower rpm turbo response, I have used the GT30 turbo assembly in a machined out stock turbo housing. However this knocks the upper power band around. I did discuss this issue with the customer, but after the test drive , he now thinks he made the wrong exhaust housing choice !

Cheers Mike

Legionnaire · Post by **Legionnaire** » Fri Oct 24, 2008 7:45 am

Hey, thanks for the update!

What rear housing is he using? I thought, that 0.63 A/R'd GT30 makes a pretty responsive package on RB25 (although may choke top end a bit). It also obviously comes down to exhaust maifold design. One of Neos here has IW 3076 with 0.82 rear on HPI "stockmount" mani and has 16 psi at around 3500 at 4th gear.

Does your customer run stock cams?

PL,

Yeah, stock sidemount is a joke - a couple of full throttle runs - and intake temps hit 60-65 oC mark and engine loses its power.
Stock IC also has some strange-shaped snorkel, that almost covers a half of IC. We were able to prolong engine's full power to 4-5 full throttle runs (instead of 2) on a stock IC by getting rid of snorkel and making adequate air ducting to and from IC

I'll post my results with 3071 as soon as we have it assemled and tuned