Forward Facing Plenum

[gogglez-10]

just wondering if its worth me goin for a forward facing plenum to try and lower lag on the setup i'm startin to install of a gt3540 turbo on low mount with external gate and screamer pipe with nistune board and fuel system coming in the next few weeks? All advice is appreciated as I'm fairly new to rbs

[KiwiRS4T]

More to the point is what exhaust housing have you got on the GT3540? I think you'll be scratching to fit a GT3540 on a low mount (not saying it can't be done). Have you got an RB25DET or have you put a 30 block on it? What is your power goal? I would say the GT35/40 is too big for an RB25 and bound to lack response. I have an RB3540 with a .63 exhaust housing on my RB30/25 and I don't notice any lag.

If your power target is 300kw or below there's no need to change the inlet manifold. I guess you know a screamer pipe is illegal most places.

[gogglez-10]

its just a stock 25 neo rear housing is a .76 and wanting about 250+ atw and i know screamers are a No go but our local police have next to No idea they thought my 300rwkw Aristo was a mere camry

[pipster11]

Thats way overkill for 250+kw

Neo highflow will max out at about 260 and be waaaaaaay more responsive than the 3540

In the fat lard that is a stagea you will probably find response makes them faster than absolute power

[gogglez-10]

reason I'm sayin somethin so big is cause i got one have also been thinkin of a gt2872r. not too keen on highflowing especially if i get more power hungry and it starts maxing out at 260

[0t1]

Use it nothing wrong with 3540 on a 25 with the right supporting mods, injectors, aftermarket ECU, exhaust etc good for 265rwkw. run on E85 and 1 bar 350+rwkw. It's a real hassel to mount on low manifold.

We've been running a few 3540's on RB's for ages, we use .86 housing on top mount manifold with FFP, gate to atmos, 3." exhaust, flip the intercooler upsidedown and the piping is a total of <1m. lag is adjusted via clutch pedal.

25, 26 & 30's.

[KiwiRS4T]

I guess its a cheap Ebay turbo. However for 250kw you should just get Hypergear to highflow your turbo then you won't have any installation hassles. If you want more power a GT3076 will low mount with a 10mm spacer and make 300kw on 98 or more on E85 if you want later and be much more responsive than a GT35/40.

[gogglez-10]

35/40 a cheap ebay job i think your mistaken No offence also not a huge fan of hypergear as they use kinugawa internals have used glen munro from Brisbane quality work at reasonable prices

[pipster11]

you are quite misinformed about both hypergear and kinugawa

hypergear makes his own stuff, yes he doesn't use ball bearings he uses bush bearings

but i doubt that you will find a manufacturer that will back up his product as much as stao, he has even taken his old turbo bought second hand and updated them to the latest spec for about $400

kinugawa also uses mitsubishi chra's and stuffs them into his own housings afaik

both are well founded and have low to no reliability issues

stao is constantly testing on his rb25 so his turbo's are perfect for them, he knows what works and if you talk to him about what you want he will make sure to deliver something that performs how

you want it

also, you can get cheap dodgey ebay 35/40's so kiwi's response was valid

back on topic, the long inlet runners of the stock over-the-top intake manifold give good low-midrange torque

its well documented on this forum that front facing manifolds loose this torque are rarely increase top end, but they do help tidy up the engine bay and make the piping shorter when running a fmic

if you went ff plenum and the 3540 you will not decrease lag as plenum design is much more important than the frictional resistance of a metre of pipe

[4bidn1]

Yeah def misinformed as stated above stao makes his own with more back to back testing than you want to know about.. and kinugawas do use mitsi internals , got one in the shed. fitting a 3540 low mount hmmmm my 3076r only just squeezes in from looking when we where stuffing around with my mates 35 40 you will have no room. for the power your looking for there are heaps more viable turbo options than that even if you get power hungry much more responsive mid 300s are quite capable out of much more suitable turbos . have nothing against the good old 3540 used one with a .82 on my vl. much better suited to a 3L engine . and yeah save the coin from a ffp not needed till much bigger kws unless ya just want engine bay.to look lot cleaner.

[KiwiRS4T]

I assumed you had an ebay turbo because to my knowledge the Garrett GT3540 come with 0.63 (mine) 0.82 or 1.06 exhaust housings whereas the cheap knockoffs come in a variety of a/rs. In any case pretty sure you won't be able to low mount one. Mine only just fits with my custom high mount:

[gogglez-10]

cheers I'll be giving a few workshops in town some calls today and see what they recommend but will be goin for a new turbo and sellin my 35/40 off with both rear housings

[66yostagea]

I Have an ffp, not for power only to tidy up the engine bay and make it easier to change the plugs, but it will be a bastard to get to the cold start etc.

Also, and I believe it is a common problem that it gets the gurgles once the oil temp gets over 100. I will soon fit the oil cooler to see if that solves the problem

[OMY31T]

ntohing wrong with kinugawa, i just sold my r33 skyline with a kinugawa T67, it made 255rwkw, and the auto died, only got to tune it @ 17psi on bp98, and we suspect the gearbox was slipping the whole time it was on the dyno before it went. the setup should have easily seen 300+ on 20psi... and around 350rwkw on E85, which has been proven time and time again on this forum without failure so far.

i am aiming at around 250-260rwkw @17-18psi in my c34. i have so far done FMIC, walbro fuel pump + direct 12v feed mod, sard 650cc injectors, still to come z32 afm, coilpacks( not really neccesary), hypergear highflowed op6 neo turbo, and nistune.

as for hypergear, trent from status(chequered) tuning tunes my cars, and he will back hypergear turbos, he never used to when stao first started because they werent quality, but the way they are built nowdays, he has no issues tuning with the, nor testing them for stao at hypergear, and he is one hell of a tuner with a very good reputation.

Edited September 24, 2012 by OMY31T

[Raysboostin]

I think u'll find a 3540 way to big to be practical in a stagea. With stags being so heavy it will fairly laggy with a 25. The idea of clutch kicking to get rid of lag might work for cop bait morons in rwd skylines, but with and awd stagea ur just gonna keep burning out clutches or breaking stuff. For your power goal id go way smaller. even a 3071 is more than ud want. Save your 3540 for a big $$$$$ dirty 30!