Gt 35/82r Too Laggy For A 25?

[HARDCORE]

Im upgrading my turbo,and just wanted to know if anyone else is running a garret GT35/82?iv been told it will be to laggy,an to go with a 30/71r or 30/82r,I am after good response but dont mind if it makes full boost around say 3500-4000 tops,so if any one else is running one of the above any advise would be great...

cheerz

[silva33]

How much power are you looking at making and do you have a built motor to handle what a GT35 can put out?

I think that you will find a GT30 turbo will be large enough to put out some very decent power.

[WARDY32]

Im running a GT35R on my internally standard RB25, it has the .82 rear housing and it makes the current full boost (11psi) at bout 3800rpm or therabouts, of course the more boost you run the longer it takes to reach it. If response is your adjective them i would give one of the GT30 framed turbos a go. A mate has one on his RB25 VL and it makes 285rwkw at 1 bar (with supporting mods)

[unique1]

depending on your power expectations the best bet is the gt3076r (56 trim), these are making good numbers around the 400-420rwhp mark on 20psi or so and very very responsive. my mate runs a gt35 on his rb26 and fullboost isnt till around 4000rpm which is abit much and unless u have a built motor i wouldnt go that big.

[wolverine]

^^^x2

[116.hks]

Hey mate. I'm running one of these in 32 with a 25 in it. Really nice turbo. Don't really notice the lag much. At about 3800 shes ready to go and pulls all the way to redline. Nice power curve as well. Depending on ya tuner, my boost comes on gradually through to redline, instead of coming on to hard. Made a very reliable 424rwhp on 20psi. In my opinnion they are a nice turbo. Also check out MR turbos ( Billet turbos), as they make a similar turbo with different trims.

[_Ryan_]

250-280 get a 2835spec GT3071r: http://www.gcg.com.au/turbo/ViewProduct.aspx?ProductID=202

for 290-320 grab a 3076 .86(i think)

for more than that go RB30e bottom end with your head and a sump adapter and bolt on that 35/82r

[GoldZilla]

Hey mate. I'm running one of these in 32 with a 25 in it. Really nice turbo. Don't really notice the lag much. At about 3800 shes ready to go and pulls all the way to redline. Nice power curve as well. Depending on ya tuner, my boost comes on gradually through to redline, instead of coming on to hard. Made a very reliable 424rwhp on 20psi. In my opinnion they are a nice turbo. Also check out MR turbos ( Billet turbos), as they make a similar turbo with different trims.

I'm with everyone else in saying that a 35-framed turbo would probably be a bit big and laggy on a Stagea. IMO, having it on an RB25 in an R32 would be quite a bit different due to the fact that the R32 is a much lighter car. In the Stagea, you'd want the boost to come on earlier to overcome the extra weight being carried around, especially with an auto.

If I had a biggish turbo on a car I was using as my daily driver, it would probably eventually get on my nerves as I prefer to have a good amount of low-end response balanced with the higher-rev power. Even though it has potential to use less fuel (due to spending less time on boost), I would rather have the response available to me when I needed it - then again, I don't drive for economy, anyway...

[pixel8r]

I've owned a stagea with a GT3071r in it, and even a GT30 is laggy (remembering that different people have a different tolerance for what they'd call laggy).

Response and top end power are at opposite ends of the spectrum - so if you want response - the stock turbo will win hands down, but if you want power, then the GT30 should be ample.

Basically the minimum you need to go with the bigger turbo is a free-flowing 3+ inch exhaust & dump pipe, piggyback or full ecu (incl ignition timing if possible), and obviously boost controller, then injectors/fuel pressure regulators, fuel pump (etc. etc. to handle the extra fuel), and last but not least, upgraded brakes and all the things associated with stopping faster.

Stageas are heavy and therefore your biggest issue is torque. The RB25 neo isn't too bad for a 2.5L motor but has nowhere near enough torque to handle the weight of the stagea without the turbo. Also, the hotter the weather, or if you're running air con, the more strain on the motor - so that reduces torque as well.

Torque is the main factor in how quickly your turbo spools up, so realising that the RB25 doesn't have a huge amount of low-end torque (under 2000-2500rpm), you really want the turbo spooling as early as possible. if the turbo STARTS spooling even 500rpm later, its going to feel noticeably laggier.

I found that most of the time when just cruising around, the most used rev range is between 1800-3500 rpm - if your turbo hits full boost within this range, the car will feel much more responsive. Mine unfortunately didn't hit full boost until about 3700rpm and whilst it pulled pretty strong from there to redline, it really was very unusable power in average driving...making it very frustrating at times. An ecu to tune ignition timing can make it rev up quicker, thus reducing the time it takes to get on boost, but this is the one thing I didn't have (my piggyback ecu only tuned air/fuel ratios) so I cant comment on this.

I believe a lot of money on engine mods, including major modifications to the engine itself, can overcome most of the lag issues for a bigger turbo, but the question that needs to be asked is "how much power do you actually want? and can you get it with a smaller turbo".

Its better to run a small turbo at its peak than a large turbo that hardly enters its efficiency range. A small, responsive turbo in my opinion is going to make your car feel a LOT faster than a big laggy one - but by small I'm talking something in the GT28 range. Just keep it close to the stock size but with steel internals for higher boost and reliability. Find something that'll handle 16-18 psi or thereabouts (ie. reliably, not maximum). You should be able to hit 220+awkw with a GT28 turbo and have a much faster car than if you follow the GT30 route.

A large turbo doesn't give you a faster car...it gives you a slower one every day that just happens to give you a rush at 4000rpm on the drag strip...but 90% of your daily driving you'll be slower than a corolla.

The only exception is if you spend a lot of money on mods - but if you have this amount of money - you'd be better off just buying a faster car...hope that makes sense

[HARDCORE]

How much power are you looking at making and do you have a built motor to handle what a GT35 can put out?

I think that you will find a GT30 turbo will be large enough to put out some very decent power.

around 250awkw,the internals are standard and i would rather keep it that way because buy the time build a forged motor and bolt every thing on you looking sort of around $20g and if its gona cost me that id rather chuck in a 26,so yeah a GT 30 sould do it.

[HARDCORE]

I'm with everyone else in saying that a 35-framed turbo would probably be a bit big and laggy on a Stagea. IMO, having it on an RB25 in an R32 would be quite a bit different due to the fact that the R32 is a much lighter car. In the Stagea, you'd want the boost to come on earlier to overcome the extra weight being carried around, especially with an auto.

If I had a biggish turbo on a car I was using as my daily driver, it would probably eventually get on my nerves as I prefer to have a good amount of low-end response balanced with the higher-rev power. Even though it has potential to use less fuel (due to spending less time on boost), I would rather have the response available to me when I needed it - then again, I don't drive for economy, anyway...

yeah that was my main concern the weight with a 35,yeah respose is what id prefer to.

[unique1]

there is alot of gt30 options remember, a gt3082r is not a good choice either as i have read it has almost the same boost response as a gt3582 but cost alot of top end power, the gt3076r is the best option and highly spoken about on the forced induction section of these forums. i got one on my 26/30 and i think its actually too responsive but thats on a 3L, it would suit a 2.5L perfectly.

[_Ryan_]

GTRS, 240-250AWKW, responsive.

2835(3071r) would also do it

3037(3076r) is a 300kw turbo... overkill!

[unique1]

overkill i dont think so, its gonna be soo responsive anyway, its not going to be pushing 25psi to make the numbers and it will be suitable for any future plans for abit more power, its not laggy one bit i actually think its annoying how responsive it is on a 3l i have removed it. its spooling and coming on boost under 2000rpm easy (remember this is on a 3L) which is sometimes annoying if u wanna cruise around offboost its rather touchy on the throttle.

[_Ryan_]

overkill i dont think so, its gonna be soo responsive anyway, its not going to be pushing 25psi to make the numbers and it will be suitable for any future plans for abit more power, its not laggy one bit i actually think its annoying how responsive it is on a 3l i have removed it. its spooling and coming on boost under 2000rpm easy (remember this is on a 3L) which is sometimes annoying if u wanna cruise around offboost its rather touchy on the throttle.

yeah, overkill for 250 on a 25 tho

[bubba]

The hiflow on my Stag is rather laggy.. starts doing something about 3500rpm and around 4000rpm she pulls hard. But being a big heavy auto bus, 4000rpm is far too late! A bigger stall would help but would destroy the daily drivability.. go for something smaller that's on full song by 3000rpm..

[unique1]

The hiflow on my Stag is rather laggy.. starts doing something about 3500rpm and around 4000rpm she pulls hard. But being a big heavy auto bus, 4000rpm is far too late! A bigger stall would help but would destroy the daily drivability.. go for something smaller that's on full song by 3000rpm..

or put a manual in it and give it some revs Yours actually goes really well mate, great package u got and the car looks nice too, im not usually a fan of s2's but it does look good

[wolverine]

4000rpm for a hi-flow = something is wrong.

does the wastegate actuator have enough pre-load?

where is the hi-flow from?

[bubba]

or put a manual in it and give it some revs Yours actually goes really well mate, great package u got and the car looks nice too, im not usually a fan of s2's but it does look good

Cheers dude, was fun through the hills on the weekend quite suprised how well it handled!

P.S. auto for the bus, manual for the toy 32

4000rpm for a hi-flow = something is wrong.

does the wastegate actuator have enough pre-load?

where is the hi-flow from?

Was done by a local mob over here, I imagine it's a pretty big hiflow though.. ~240awkw @ 12psi.. makes me think it's pretty big!

Haven't looked at the actuator and cbf at the moment to be honest, my 32 is in pieces so I've got enough to worry about for now

[rb30dett]

I have an rb25det and a gt35/82 so I am going to slap it all together as a budget build. standard manfold, standard plenum, etc if I have the funds I will build a budget rb30 as that was my original idea. Question is, are the gains of the rb30 worth the money when only using standard rb25 head and manifolds? should I just chuck in the 25?