Too Big Turbo Vs Normal Turbo

[R33 0wnerrr]

Well....

I brought my r33 rb25det with this insanely big turbo already on the car....looks like a gt35 front but the exhaust housing of it is huge and when i would drive the car it would lag and in first gear kick in at about 6k revs, and 2nd like 5500, but when it kicked in it would sit me back in my seat on stock 7psi,

BUT i recently brought a new DSR 430 turbo, and then raised the boost up to 10psi, it spools up at about 3k and i get full boost by about 4-4500revs

But even though i raised the boost and its hitting boost for longer in the rev range....its actually going slower then the old turbo. The old big turbo i had i would be doing about 60 before changing into 2nd and about 100 at the end of 2nd, and it was on stock 7psi but with this dsr turbo i get to about 50kph in 1st and about 90 in 2nd gear... on 10psi

The DSR turbo keeps power through all the way to redline aswell,

So is this becuase the DSR430 turbo i brought a piece of chinese crap? or do i need a really decent tune? or a high quality turbo such as a garretgt30 or somthing?

Thanks guys!

[paulr33]

you need both, the turbo sounds like ass and the tune probably hasn't been redone since you changed the turbo

[R33 0wnerrr]

you need both, the turbo sounds like ass and the tune probably hasn't been redone since you changed the turbo

Iv brought a power fc, and I have a bosch pump, going to get my injectors high flowed and have a z32 afm lying around, and my hks evc so looking to get it all put in and dyno tuned

But i dont want to have to go back wanting more power, so am wondering what would produce more power...tuned turbo i have now or the big one put back on, because i cant really afford to buy another turbo.... but i might have to i guess

[R31Nismoid]

You are running all of that on a stock ECU?

If so - thread ends. Until you get a decent tune into the setup it's impossible to say what could be wrong/better/worse due to the factory ECU having a fit.

[PM-R33]

Fark, so it was running a GT35 with probably a 1.06 exhaust housing on a stock ecu, stock injectors and stock AFM?!?!

[2BNVS]

lol jebus

[R31Nismoid]

Fark, so it was running a GT35 with probably a 1.06 exhaust housing on a stock ecu, stock injectors and stock AFM?!?!

lol you'd truely hope that wouldn't be the case wouldn't you...

[Parag0n]

Better hope you haven't caused too much detonation, your car would of been leaning out more than a f**king anorexic.

[gotRICE?]

Speed its determined by gear ratios not power.

[R33 0wnerrr]

Fark, so it was running a GT35 with probably a 1.06 exhaust housing on a stock ecu, stock injectors and stock AFM?!?!

Yep...guy i brought it off had it on with stock ecu and stock everything apart from fuel pressure reg and intercooler.... i know i need a tune but would want to sus out my turbos before i get the power fc i just brought tuned in...

And would that turbo run any good after the tune with new injectors fuel pump and a z32 etc?

Car seems to run fine so im hoping not much damage was done....

[PM-R33]

Well that turbo will make a hell of a lot more power than the standard RB25 bottom end could ever handle and the rear housing will make it laggy as hell. So yes it would run after a tune, but personally thats a bad turbo choice for what you want. So i would rip it off and sell it, or atleast get the .86 housing for it.

[NYTSKY]

Please stop saying "Brought" Its bought.

Sell the turbo, get a highflowed stock one. You will need an ECU (Your PFC). Your injectors will be ok for the power output of the highflowed turbo. You will need a decent fuel pump too.

To get efficient power out of the one you have now, it will cost you thousands.

[Adriano]

I love how people assume that a big turbo will lean out the motor and cause detonation, when with the stock ecu the opposite will occur,

[R33 0wnerrr]

Well iv still got the DSR430 turbo with a .63 exhaust housing... they claim 250kw on a standard rb25 at 1bar with only being tuned http://www.sella.co.nz/motoring/car-parts-...ssories/575cb2/

So might aswell just stick with this and wait to see how the tune comes out?

Oh and how much power can stock injectors handle? was thinking i could get them high flowed but if i dont need to i would like to save the money...

[PM-R33]

I love how people assume that a big turbo will lean out the motor and cause detonation, when with the stock ecu the opposite will occur,

Only one person mentioned detonation.

[R31Nismoid]

No surprise who it was that mentioned it either

[UWISSH!]

if you have a gt35 wouldnt it be high mounted aswell?

so if you put this other new turbo on you will also need to go back to low mount set up. which means buying manifolds and other bits.

in my opinion u should just buy the smaller ex.housing. i had a gt35 on my 33 gtst with the 0.82 and honestly its not as bad as people make them out to be

[R31Nismoid]

^ and that's the problem sometimes.

What one person calls laggy and unresponsive, another person says its not too bad.

Could be they have not been in a better setup, could be they are happy with how theirs is.

Whatever the reason, you need to be open to the idea that there can be better out there at some point.

[UWISSH!]

^ and that's the problem sometimes.

What one person calls laggy and unresponsive, another person says its not too bad.

Could be they have not been in a better setup, could be they are happy with how theirs is.

Whatever the reason, you need to be open to the idea that there can be better out there at some point.

i agree with what you have said above, everyone has there own opinions on what lag is. my opinion is based on going from a standard turbo to a hi flow and then to the gt35. i was of the opinion that it would be laggy before i bought the set up but was advised to for a drive in 1 with a gt35 set up and i was very happy with how it went so decided yeh ill do this for mine aswell. couldnt of been happier with how it turned out.

for the OP, just abit of info with my set up, we pulled 290kw atw on a standard engine with 550cc injectors, walbro fuel pump, PFC and just the usual stuff like exhaust and intercooler.

the engine was still in perfect shape aswell.

[R33 0wnerrr]

i agree with what you have said above, everyone has there own opinions on what lag is. my opinion is based on going from a standard turbo to a hi flow and then to the gt35. i was of the opinion that it would be laggy before i bought the set up but was advised to for a drive in 1 with a gt35 set up and i was very happy with how it went so decided yeh ill do this for mine aswell. couldnt of been happier with how it turned out.

for the OP, just abit of info with my set up, we pulled 290kw atw on a standard engine with 550cc injectors, walbro fuel pump, PFC and just the usual stuff like exhaust and intercooler.

the engine was still in perfect shape aswell.

wow 290atw? how much boost was he running? oh and was that with the .82 housing? when would that kick in about?

Well im happy to deal with the lag...it was bad but i want to get alot of power with what iv already got....and that turbo had it even untuned, as im unhappy with the turbo i have now...but im just unsure... if i did put that big turbo back on and had the same mods as uwissh said...or if a decent tune with the smaller turbo i have now as to which would be better power wise

But the smaller turbo im using now is more driveable seeming im not skidding out in every gear like the other turbo

Edited January 30, 2010 by R33 0wnerrr