EVOIV

I think it's almost a well known fact that HKS turbo are more efficient at high boost, and Garrett turbos more efficient at lower boost. But having said this, it would be good to have a direct comparison between an HKS and equivalent Garrett turbo. I agree, the HKS compressor maps are very hard to find - if possible. They seem very secretive about their work, and who wouldn't be The letters "HKS" are just about as reknown as "GTR"

Why don't you want the external wastegate anyway? As said previously, an external wastegate will give better/smoother flow at higher boost, and you'll have slightly better boost control. As it's an HKS turbo, which are more efficient at higher boost, you would definitely want an external gate for this turbo. I'd keep the 3037 the way it is, buy and external wastegate and manifold (or custom made). It will be much better in the long run. Should have no problems chasing 300rwkw with a 3037 on high boost.

Yes, I've read that with the stock turbos, exhaust, air filter, more boost, cams and stock internals...you can give around 250rwkw and run high 11s. But to run lower 11s you'll need upgraded internals and turbos...etc which starts to get real costly. Then for 10s I expect you'd probably need to change the gearbox soon, and that is going to be the real killer.

Once again it's all to personal preference, but once you've been in a big turbo car...it's hard to go back to the smaller turbos Although I do admit that the smaller turbo cars actually feel "faster" on the street, because they are with their quicker response and you only drive upto 60km/hr most of the time.

I've heard that the GT2540 aint a very good turbo, and that it has now been replaced with the GT-RS turbo? The GT2540 gave too little top end power in return for the increase in lag. So you would be better going the GT-RS, although this is a new turbo and probably cost a bucket load. I have read that HKS turbos are more efficient at higher boost, whereas Garrett turbos are more efficient at lower boost (eg 1bar and less). I thought HKS and Garrett turbos were just about the same, the only difference being that the HKS have specific HKS compressor trims.

Sorry to hear about the GT2530. Is the T3/T4 turbo much larger than the GT2530? It's all up to personal preference. Some people like a small, quick response turbo - better for street driving and drifitng. Whereas other people (including myself) prefer the larger turbos with a more peaky power curve - where you can actually feel the turbo. To me, standard turbos/small turbos just feel like a NA car but with more power. The power is very linear and nothing exciting at all. I prefer the thump in the chest, then the loud bark of the external wastegate Why not go get yourself a huge T-88 for the RB20? Probably an overkill. Or what about a GT2835 PRO-S? They are VERY nice. Reasonable response for street, and a fair bit of top end too! Rated at 420PS.

Yeah, it is subjective I guess. I've heard that some RWD cars running large turbos tend to wheel spin when the turbo kicks in. Can get very dangerous in the wet, but if this happens, you know that it's a pretty big thump! Never been in a car that does this, because my car is AWD and traction is rarely a problem. Though my sister has a stock s15 and it feels a lot more dangerous in the wet, even when my car had 206kW at all four wheels. It's really easy to get the rear end outwards when turning a corner (s15). And I can imagine it would be very difficult to control with 200+KW at the rear wheels. But I guess 10" width rims would give a little more traction...

I actually like the push in the chest effect that happens when a large turbo comes on boost After a while, a small turbo car just feels like an ordinary car but with more power. I actually prefer power curves to be more peaky than linear.

Hehe...cool. It doesn't seem like a lag monster if it's making boost around 2000rpm...that's actually very responsive. I used to have a GT3037S on a 2L and that was laggy, like no boost until around 3500rpm!! Too laggy for street use, but when it came on boost it was great I think I'll try the GT2835PRO S for my next 2L.

I get a little confused. Are T04's large or small?

Yeah, that's a major problem with BB turbos...they are very expensive to repair, if they can be repaired. But I've heard that they can spool up to 30% faster than normal bearing turbos. I guess there's always a trade off.

JimX: I'm a little confused, I didn't know that Garrett made normal bearing turbos? I thought they were all BB? Anyway, glad that everything worked out.

ImpulR33R: Yes, car is still for sale. If you would like more pics of the car please email me at: [email protected] oh-low: Pictures have been sent to your email.

Hmm...not sure how much better the GT-RS is, but I believe it would be better being a newer designed turbo. I thought it was supposed to supercede the 2540 which was supposed to be more laggy and give only a small increase in power. I would pay the extra money and buy the GT-RS new. Steve: I thought the GT3037S was the only "S" turbo, and as such is the only turbo to have the inducer? I know the GT2835R also has a 100mm inlet, but no inducer. The same thing goes for the GT3240. I didn't know there was another "S" turbo? Yeah, I wonder what the rationale is behind the turbo prices.

One thing that I have noticed is that the 52T 3037S always seems to cost a bit more than the 56T 3037S. Which always made me wonder, because most turbos are the same price irrelevant of their trim size?

Ahhh...I know what you mean now!! About the inducer. Yes, the inducer on the 52T showed does look like it is tapered whereas yours goes straight down. But, having said that...I am sure I remember looking at mine the other time and it does fall straight down, but maybe that was on the 56T - that was on my car. I will check tonight to see if it's so and if there is a difference between the 52T and the 56T inducer. But if you hadn't said that I wouldn't have noticed. You're very observant

How much did you buy your turbo for? I wasn't aware that there were different models of the GT3037S? I've had mine for a year now, so if anything mine would probably be the older model? Sorry, what's the inducer?

Steve: The one pictured is a 52T, but I also have a 56T trim. Actually, the one pictured is damaged (turbine wheel) but I hope to get it repaired soon, if it can be repaired. The 56T I used on my EVO4...how can you tell if it's the current or older model??? What's the difference with your turbo? Do you have a pic?

Can all Skylines have the 044 fuel pump installed in-tank? Including the GTRs? What about 180s and silvias? And here's my GT3037S, although not as shiny as the GT2530 and it needs a bit of cleaning up...

Just wondering what the following specs of people's cars were: Type of Car: Turbo used: Power: Cheers!

I guess you could measure the compressor and turbine trim to see what size they are? As for the A/R ratio, that's a bit more difficult

I did ask them for a rough quote but they won't quote you until you actually bring the turbo in. Then they'll strip the turbo down and see if it can be repaired, if it can be then they will give you an accurate quote. They will however provide a free quote, and as you're in Sydney it would be worthwhile to drop the turbo in to GCG or even better Garrett to see if it can be repaired.

You should give GCG a call. I too have a damaged HKS GT3037S ball bearing turbo, and was under the impression that BB turbos could not be repaired - until recently. My turbo have a damaged turbine wheel and I have talked to GCG and they said that they have repaired several (over 100) BB turbos in the past with 100% success rate. I am hoping to send my turbo to them (or Garrett in Sydney) soon to see if it can be repaired. There seems to be some hope in repairing BB turbos. The initial thoughts were that it wasn't possible to buy trims separately, but some companies have said that you can!? Not really sure, but I will send my turbo to Garrett (dealer in Australia) to see what they say. Hope it can be fixed...

Fair enough. What turbo are you looking at to replace the GT2530 for track use? Obviously you'd want a larger turbo, that will give more peak power but more lag. But you don't want a huge T88 that's specific for drag only. Guessing a 2835 or 3037?

Let me guess, you are upgrading to a larger turbo DoughBoy? Why the change?