R34gtt Turbo Vs. Vg30 On An Rb20det

[Birth]

Hi there,

I have a VG30 on my RB20DET R32GTS4. I am now tired of reaching full boost at / after 4,000 rpm and have decided to swap to an RB25 turbo. Searching through the forum I understand that the R34 GTt exhaust housing is the same size as the VG30. My understanding was that the lag was caused by the large exhaust housing which leads me to believe that this swap is a bad idea.

I do however understand that the turbo core and compressor / compressor housing is 'better' in the R34 GTt turbo.

I am interested on your thoughts as to whether or not this swap is worthwhile. After some reasearch I understand that a turbo from an R33 (eithe S1 or S2) will alleviate some of the lag. If the R34 turbo is a bad idea, I will go for a r33 turbo.

Your thoughts?

Edited November 6, 2007 by Birth

[ORIGIN]

i would also like to know that answer to this?

[RB20JT]

mate,

i got an r33 gcg highflow on my rb20det, starts boosting just over 3000rpm and doesnt hit full boost till 4000ish..but comes on hard after that!!!

now i dunno if there is sumthing wrong with my car and ths setup aint right...but thats my circumtances...so im considering chances turbo's to recude lag..i honeslt dont giv to farks about top end...i mean not lose heaps top end ..but i would sacrifice top end for less lag and bottom end.

what ecu u plan on using? im using std ecu with fuel cut defender..not that good to be honest..

[Birth]

Your turbo behaviour sounds exactly like mine (though I imagine yours comes on alot harder than mine). I don't mind my car when I am driving around that suburbs where there is less traffic etc, but I live in the inner west and traffic and lights etc. mean that I am never on full boost and makes the car a bit of a pig.

I will continue using my ecu which is a Tilbrook Auto tune which I modded slightly at home with ROM Edit. I use an old 5-pot Apexi SAFC to make minor changes, but I haven't made any in ages.

[RB20JT]

i was looking on ebay at those e prom things u can put in ur std ecu? supposively improves ur mid range...and it would be great to get sum of that. besides wats the point of running 14psi when u dont get it till 4-5000 rpm...annoying.

anyone had experiences with these things?

[Bass Junky]

If you are going to change to an R34 turbo, do that. The R34 turbo has a better compressor design than the VG30 model of that turbo.

[Granthem]

Nylon compressor wheel on the R34GTT turbo allows for less weight and therefore increased spool i believe.

[RipNGrip]

YEh.. one of the r33 s1 or s2 has a nylon wheel which is easier to spool up. my mate has one on his rb20det sylvia boost around 3. I have a sliding performance high flow boost around 4.5/5 grand bigger house in compressor and exhaust sizing witha steel wheel..........14 psi at 5000 rpm....... ANNNOYING

[RB20JT]

i agree!! hmm...wat to do?

[sloutch]

Weird some of you guys have a very laggy VG30.

My VG30 hi flow on my R34 gets to full boost at 12psi at about 3600rpm, making 240rwkw with just that 12 psi. At 1 bar hoping for 250 or more after i get a better aftermarket ECU.

[RB20JT]

ey wait....im assuming that if i actually got a friggen aftermarket ecu of a blitz access tuned ecu it would alot better!!! wat u's reckon?

[JDM032]

the only reason urs is hittin boost earlier then the other pplz on here is coz u got a 34 which is 2.5 litre, we all got 2 litres so the bigger turbo takes longer to spool.

pplz u just gotta remember that these turbz were made for a 3 litre twin turbo not a 2 litre single, hence why comin on boost late.

the best way for great power and early boost for all the 32 boys out there is to get a HKS 25/10, small but still packs a shit load of a punch.

btw i got vg30 on mine n it sucks for drifting but love it on the road coz the V8 boys think there winning then all of a sudden boom u pass em, mate its soo good lol

[sloutch]

Ahhh...that explains..i was referring to RipNGrip's thread about having 14psi at 5000rpm. Didn't notice he has an Rb20.

These turbos are not made for twin turbo 3litres VG30DETT, it is from the single turbo VG30s