R34gtt Gt35r Stock Internals :)

[SirRacer]

get a 44 gate, if your doing the rest of the setup properly its stupid to scrimp on this

[drmafia]

seems like the 60 mill will work fine for 15 -19 psi boost as my exohst system is VERY OPEN.. so im getting the 60 mill one but i asked them if they think the 45 mill will be better ill pay more just give me what ever works best.. they will get back to me 2moro im assuming. everyone seems to say different things. Kyle from 6boost who is making my manifold said the 60 will be ok to run the boost i need specialy since my exohst is soo well flowing.. n the 38 is too small..

[GeeTR]

Speaking waste gates, from my limited experience, its the larger diaphragm thats the big plus, not so much the valve size. Go 60mm.

GT35 is too big to simply run low 1.5bar boost. Unless your guna push the GT35, get a smaller turbo to get the same power, with less lag.

As for power limits of RB25, like a lot of things its tune related. People get mixed results because cylinder pressures caused by det aren't progressive. As long as you can assure a det free environment ALL the time, (v.unlikely for most people) then you can push any motor very hard and only really see normal engine wear, IE rings, bearings.

Simply saying your aiming for a tune with low det is pretty meaningless. If your going to push the limits of cyl pressure (so intake heat, ignition advance, AFR's) make sure you do everything possible to prevent ANY det. This could include guaranteeing fuel pump, reg, inj, coolant flow, ECU, fuel etc health. Rem after market head gaskets, forgies etc are more for det resistance, then for handling increased power. A built motor (piston variety at least) will take a bit of cyl pressure spiking, whereas the high strung stocky will bust a ring land, spit a gasket.

my 2cents

Edited January 7, 2008 by GeeTR

[Sydneykid]

the list up there is a list of parts i have already got, not im going to get apart from the spitfire coil packs which i dont think i need but ill know on dyno i guess, tried to get in touch with 6boost "kyle" but seems like they are closed and i doubt they can make me on in the next 15days which is when i need one by. and the waistgates already payed for just gata pick one of the two sizes they have in stock seems like ill go the smaller one 38mm. seems like not runing a ebc or runing the profec b is the prefaired option from what a few of you guys have responded so i might see both of them or run the profec b depending on what the work shop thinks when i take it there.

the turbo im not going to buy a 3rd one its one of the two but seems like its the gt35r as i said i dont mind doing the internals if/when i blow them that is. but should be ok with 300rwk im hoping or just a tick over.

was also considering installing a nos kit just for spooling up the turbo faster on the q/m but that ill still have to think about after a few runs as i want to know what times im in and if its close to the mid 11s im chasing or not..

so far im thinking ill have it up to 300rwkw and around 17-19psi alto im tempted to test the internals limits as i dont mind rebuilding it at the moment just not now.. maybe in a few months time when and if i get bored of 300kw which I should be happy with.

thanks for all the pms much appreciated. post here tho cuz my inbox keeps gettin full

The problem as I see it is that you have bought a bunch of parts without really having a plan to buy them for. You don't really have a target power output, I haven't seen anything about what you are going to use the car for, is it 100% a street car, a drag car, a track day car, a dyno queen, or all of the above? This is all important stuff, because what suites one power target may not suite the usage pattern that you have in mind. Let me give you a couple of quick examples;

If it's a 100% road car, then a GT35 is far too big for a 2.5 litre with a standard internals' rev limit. You will get your ass handed to you by every taxi in town. It will be virtually impossible to launch fast on the crap road surfaces we have to put up with, when it rains you are totally screwed. It will dop off boost on every gear change as the power band will be too narrow. To make 300 rwkw the GT35 will be operating well outside of its efficiency range, creating unnecessary lag for no good reason. Have you ever looked at a compressor map for a GT35? It's not a bad place to start.

With the standard internals you can't simply rev it more to get a wider power band. Keep in mind that every 500 rpm increase = double the load on the up and down bits (pistons, rods etc). You can't tune it lean and advanced to improved the efficiency, as the pistons and rings simply won't tolerate the occasional detonation that will occur. Hot days, traffic, slightly off batch of fuel etc etc are all killers when you are on the limit. Tune it safe and it will have lousy throttle response and even more lag.

Your mate with the EVO will be onto his second beer before you even make it into the parking lot.

Briefly, as a track day car it will be a dissaster, the piss poor throttle response will make it virtually impossible to drive on the throttle, corner speed will suffer markedly. You won't be able to do more than a handfull of laps before the frightening thought of heat soak induced detonation will have you heading for the pits. As a drag car you beter ditch the manual and get an auto as that's about the only thing that will give you decent times/speeds with standard 2.5l internals and a GT35. You could always add a squirt of nitrous to get that inefficiently operating turbo up to speed, but that's just a tad risky with standard internals.

In summary, think about what it is that you are trying to achieve and only use and/or buy those parts that match that goal. You can't really ask us for advice on what to do when we don't know where you want to go.

Cheers

Gary

[tridentt150v]

ringlands are the common death.

Sometimes pistons (due to poor tuning), or rods due to a bit more stress/RPM than should be applied.

Ive seen stress on other parts as well with over 25psi+ in the belly of it

Not saying Jap dynos arent accurate, its just their results differ to what we would see here by a noticeable margin (not 2%).

Supporting your argument - And you could maybe take another 20 or so off for octane??? Although some servo's now sell 100+, it isn't as common in Oz.

[drmafia]

thanks for the two very good posts, the aim of the car is 70% dayly and the rest is Drag ad im aiming for 11.5 or lower.

i Might get internals as i do wana put some Nos on too. but was thinking of doing that once i blow this engin up.. and realise how much it can be pushed..

all the work to stop det has been done. car is very reliable on fule.. with a good tune should be ok..

any idias on how to get it down in the 11.5 mark lower with this set up and im also lookin at getting a lsd if needed.

I have done some thinking and i might as well go forged pistons and rods i guess, any recomendations where to buy and what brands ? seems like i wont be able to get the 11.5 without blowing somethin out and there is no point with all this investment not to go all the way to finish it off where i want it to be..

i was thinking hks or tomi internals and head gaskit but there is also the cheaper CP Pistons --- $759USD Eagle Rod --- $550 USD Cometic Head Gasket --- $140 USD

Edited January 8, 2008 by drmafia

[Sydneykid]

My R34GTT ran 11.9 at 120 mph with 265 rwkw (GCG High Flow) and 11.6 at 125 mph with 305 rwkw (GT30). I could do the 11.9's fairly consistently, say 6 out of 10 runs. But the 11.6 was very tricky and despite many years of experience, I could only get it right about 3 out of 10 runs. That was because of the small window the 2.5L provided at 305 rwkw, get the launch wrong and it was either bog or wheelspin city. Not time the upshifts (1 to 2, 2 to 3, 3 to 4) perfectlyand it would drop off boost during the run. And that was on a prepared track, with set up suspension using drag radials, on the street it was even harder. Eventually, in frustration, I went back to the 265 rwkw spec and it was a much better/easier/nicer car to drive that was faster 3 times out of 10.

All of the above was with the standard diff and gearbox and an OS Giken twin plate clutch. I only broke one driveshaft, twisted a tailshaft twice and ripped the clutch centre out once. it's tough on the drivetrain, but you get nothing for nothing in motorsport.

Cheers

Gary

[drmafia]

mmm im on 275s at the moment and im going to put a lsd on as well i guess. if need be ill go up to 285s.

iv been told by a cupple of local tuners that its ok to dump the g35r and the cams on the standard motor with a real safe "rich retard tune" it should be ok.. but they dont wana push over the 315kwatw max.. depending on what happens on dyno how ever im seriously considering getting forged rods and pistons and a thick metal gaskit if that will get me my constant 11.5 sec.

ill be using lunch control "BeeR" so getting off the line kinda will get better with some practice i hope once im use to it.. going side ways is more the problem but its a fun problem till u hit somethin that is ..

where should i buy forgies from for a good price ? and is it enough to just get rods and pistons ?

[GeeTR]

If your going GT35, a traction control device would help a lot. http://www.racelogic.co.uk/?show=Traction_Control

A dude i knows fitted one to a 400hp RX7 S6. Pure race.

Dial in the desired wheel slip %, set the rev limit, set the launch rev limit, place a switch on the clutch for flat shifting. Id have one now, if I had a RWD.

Look into to it, if your serious about ripping down the 1/4 with a large tahbin, i cant think of ne thing better

[drmafia]

mm assuming that RLTC6DIA Adjustable Traction Control (6 Cyl) + Launch Control ABS + Digital Adjuster £695 is the one that would be best fitting on a gtt "this dosent say much about turbo" but ill look into it as its a little bit of a high price but if it workes very well and dosnt choke and makes the ride more joyfull then i might look into it after i get the car ready and put new 275s on with more grip than the ones i got on at the moment..

it is a very pricy unit i was thinking a lil nos to spool the turbo a lil faster will go a longer way down the 1/4 mile.

[Cjmartz2k]

As for power limits of RB25, like a lot of things its tune related. People get mixed results because cylinder pressures caused by det aren't progressive. As long as you can assure a det free environment ALL the time, (v.unlikely for most people) then you can push any motor very hard and only really see normal engine wear, IE rings, bearings.

Simply saying your aiming for a tune with low det is pretty meaningless. If your going to push the limits of cyl pressure (so intake heat, ignition advance, AFR's) make sure you do everything possible to prevent ANY det. This could include guaranteeing fuel pump, reg, inj, coolant flow, ECU, fuel etc health. Rem after market head gaskets, forgies etc are more for det resistance, then for handling increased power. A built motor (piston variety at least) will take a bit of cyl pressure spiking, whereas the high strung stocky will bust a ring land, spit a gasket.

my 2cents

Very well put.I know I will blow my motor up sooner or later, but it's going to be because of bad gas or over revving or something like that. Would my motor survive some of that down around 300rwhp? Sure. I choose to try and avoid those and live much higher on the hp ladder.

[N I B]

http://www.nengun.com/member/sky-34

This is around 415rwhp,stock inturnals and real soft tune.

Edited January 9, 2008 by N I B

[VB-]

sydneykid, what boost were you running to make 305rkw? and how were you having problems dropping off boost, the GT30 is a pretty small turbo. you woulda been at the upper limit of its effeciency range at 305rwkw wouldnt you?

[drmafia]

thanks, im gana do it without the internals just for a few months then do a rebuild when needed or bored and want more i guess.

this car is very close to my setup except he has 800cc injectors which i think are far too much for this application. and dosnet have cams and a few other things but looks very nice in the engin bay.

http://www.nengun.com/member/sky-34

This is around 415rwhp,stock inturnals and real soft tune.

[N I B]

800cc injectors are for the future RB30/25 engine.

[drmafia]

roughly how much is the cost of going for a rb30 / neo head ? and what parts should i be looking at getting ?

would this get me my 11.5 and lower provided i have traction sorted with tyers and lsd and that traction control system listed up there ?

[VB-]

mate is getting this done atm to his R34, hes spending somewhere in the vicinity of 20 grand, but thats with turbo/fuel system/clutch etc

[drmafia]

wow sounds nice that one would love to see his project when its done. im a lil on a tight time schedule so i need the car back on the road asap.. im not sure if ill just not bother with engin just yet or if i can get the parts in the next 10days for the engin build to forged pistons and rods and rb30 botom, what parts do i need by the way ?

Edited January 10, 2008 by drmafia