R33 Sii - My Gt30 Upgrade Is Done. Lots Of Pics

[ECR033]

ill try grab one in the new year

should still be on my tuners dyno.

my graph was similar to yours, RNZ11's graph is very snappy, mine was far more linear making solid power early and then a nice rise to the peak

<{POST_SNAPBACK}>

That would be good, I'd be interested to have a look at it - thanks mate

did a 12.1 in it, it was still sliding all over the shop so i'd say its your driving   i did a 12.9 with 200rwkw

<{POST_SNAPBACK}>

I know this is a little off topic, but is there any chance you have a copy of your timeslip somewhere?

I've done 6 or 7 runs in the thing since I got it back last month and I've got 12.7** @ 114-115mph on all but 1 run. I'd love to figure out where I'm loosing the time as my mph indicates that I should be running a fair bit quicker. Hopefully it's just my driving lol

[33SOM]

I just went for a drive in a mates 33. It has a GT30 with a .63 rear Hi mounted. It was making 12psi @ about 4000-4100 rpm in 2nd gear. It hasnt had a proper tune yet either.

Just thought id mention this

Edited December 30, 2005 by 33SOM

[The Mafia]

I just went for a drive in a mates 33. It has a GT30 with a .63 rear Hi mounted. It was making 12psi @ about 4000-4100 rpm in 2nd gear. It hasnt had a proper tune yet either.

Just thought id mention this

<{POST_SNAPBACK}>

thats awesome. Can you get the stats of the turbo?

So guys, what do you think is a final solution?

leave the VG30 on, and get a smaller compressor wheel at the same time so the the ex side of things can get the compressor wheel spooling earlier, instead of this one where its too heavy and taking forever to build up speed?

I'm thinking thats the problem, the comp wheel is too heavy and grabby creating alot of weight on the exhaust side of things.

Maybe even a smaller comp wheel, and the RB25 ex housing? Becuse when I take this turbo off, I want to do it all at once to prevent fcuking around as I'm broke...

I would like a final suggestion from these people and anyone else that thinks they know what the go is :

Cubes

Discopotato

DaleFZ1

R31 Nismoid

BHdave

Thanks guys, you have been an excellent help for me.. I really appreciate it.

Edited December 30, 2005 by The Mafia

[discopotato03]

Do you have alternate wheels in the short term ? Or do you have enough std bits to get it back to std ?

If either is the case I'd pull the turbo /dump pipe off and try to sell it - trouble is you're selling someone your problem . Sell it with the oil and water fittings as they probably won't suit the next turbo and sweetener for the buyer . If you can wait till March there is supposed to be some real T3 flanged GT30 integral gate exhaust housings coming onto the market at long last . This should solve most of these dramas with GT30 based turbos . Little late I know but I wish the bastards would stop selling those turbos to the unsuspecting .

Anyway if you can turn the sow's ear into folding stuff its a start .

Cheers A .

[The Mafia]

I've got no standard bits I just wanted to change the compressor and and a few smaller things like that retaining the core.

Maybe I should just wait till garret releases this back end and put it on my GT30, and sell the VG30 housing?

[paulr33]

take the turbo off, fit a hks gt-rs and be happy with around 260rwkw ish

you should be able to get that power fairly easily. given you don't have readily avaiable 98 octane fuel getting a big sucker that isn't as laggy wont help your situation. get a good responsive turbo that you can run mediocreish on normal unleaded and a tune to suit that. the gt-rs seemed to have best average power and least lag out of the 6 compared turbo's below

http://www.skylinesaustralia.com/forums/in...e=post&id=16353

estimated power comparison chart i made up from some of the dyno sheets found in the rb25 turbo upgrade pages

[paulr33]

your biggest problem is octane fuel so using a higher powered turbocharger wont work out as you need high octane fuel to suit an application like that

[Dale FZ1]

Do you have alternate wheels in the short term ?

<{POST_SNAPBACK}>

Showing my ignorance of Garrett product, but can you share whether there is a suitable 76mm wheel in smaller trim size with fewer than 7 blades? If so, is it an expensive proposition to swap in a different impeller?

Still mulling over those flow maps you provided too - great stuff!!

The initial feeling is that the flow capabilities of the compressor and engine are mismatched, and I'm having a look at that aspect, with the assistance of the tutorials at turbobygarrett.com, and the maps provided by Discopotato03

Big power from a moderate-small capacity road engine while retaining low-lag (note : not lag-free) response is not going to be easy. 320 odd kW (crank) from 2.5 litres is big power, and that concept of average power through the range comes back into focus when looking at response and useable power. Otherwise all those engineers would have got all their turbo matches spot-on. It's clear to me that virtually all engineering requires a degree of compromise.

Paul, we don't know for sure whether fuel is a major issue or not. I believe Mafia has to try a simple test to eliminate that from the equation. In the absence of pump 98 octane, it might be worthwhile getting a quantity of aviation fuel and do a dyno run. That will give him some answers about the top-end pinging initially complained about.

The GT-RS would have to be a pretty good unit but there's not a lot of comment out there by people who are running them. Likewise the 2835 Pro-S, though I've heard they tend to come on with a rush (that coming from a member who is running a 2530, against his brother's 2835). As with most things it's a case of knowing what characteristics are most desired ie. the compromises to accept or reject.

I'll post a bit more later on.

cheers

[discopotato03]

I wish it was as simple as buying another compressor wheel and fitting it . If one was very lucky and came across the remains of a damaged turbo and good compressor it may be possible . Generally 2nd hand wheels are the only spares for the BB's but the situation may change next year .

I've no idea if there is any back spacing difference between the TO4S and 76mm GT wheels . The GT wheel would almost certainly have a different cross sectional profile and tip height so the housing would need to be re machined to suit and anyhow its a TO4S where the 76mm GT wheels use TO4E housings .

Even if you got that far the turbine is the cropped version so only HKS do exhaust housings in T3 flange to suit . Garrett do a factory bored out (bodged) GT28 integral gate housing that fits but it won't work much better than that bored VG30 and it has the wrong (T28) flange .

Sorry , wish I had some good news , A .

[Cubes]

My suggestion.....

Don't waste money on fitting other turbo's etc just yet.

Pick up a running with good compression RB30e, don't rebuild it but simply drop your head on it. The comp ratio will drop to around 8.2-8.3:1 which will help with the 95ron fuel you are running.

See how the turbo goes then. Spool should drop 600-700rpm or so.

Thats if you can get away with doing the labour your self.

Sell off your good condition rb25det bottom end and you should break even.

Sky30 has done this... Picked up a good condition 270,000km RB30E for $50, dropped it in his R32 with an rb25 head, pushed some boost in to it via his rb20t high flow turbo and made 240rwkw, drove it like that for 1 year, pulled the turbo off dropped on a gt35r with a .82 machined up diesel internal gate housing, dialed in 19psi and made 312rwkw which has since been running for another year. In total he's racked up 40,000km's, he only rev's it to ~6500rpm.

Edited December 30, 2005 by Cubes

[BHDave]

Damn! I like cubes' idea!

Trying the machined rb housing is probably the cheapest way you are going to get out of this and end of the day it may work wonders.

Messing around with the front end of the turbo is more likely going to cause further issue, particularly if you are going to need further machine work to fit alternate wheels into different front housings. By the time you do all that you may as well get another turbo.

Ideally i'd be looking for a smaller off the shelf internal gate turbo that is smack in the middle of it's efficiency at about 1 bar mainly due to the lack of 98 octane fuel you have. Id be setting a goal of around 230rwkw with very good response so a gtrs should do it, or a second hand hks2535, or even one of the 2871 range with an adapter (though thats not ideal).

But before i did any of that i'd spend the hundred on the rb exhaust housing trial. No point spending thousands without trying a cheap alternative.

[R31Nismoid]

Mafia

Few Q's

1) Have you had a chance to use fuel, and will you have a chance?

2) Have you thought about another tuner yet/spoken to somewhere else?

3) What are you exact goals from your car, what rpm you want boost/what power etc etc

I think that would help a tad for me to think some more

[The Mafia]

Mafia

Few Q's

1) Have you had a chance to use fuel, and will you have a chance?

2) Have you thought about another tuner yet/spoken to somewhere else?

3) What are you exact goals from your car, what rpm you want boost/what power etc etc

I think that would help a tad for me to think some more

<{POST_SNAPBACK}>

no worries

1. Haven't managed any AV gas yet. Getting close though..

2. Haven't been able to leave town to see another tuner. The dude that did my car, sadly is the best we got.

3. I want full boost in 2nd \ 3rd all in by about 3500rpm max, earlier if possible.

Questions about the RB30de that sky30 dropped in cubes - Having that low of Compression, was it a dog off boost?

[R31Nismoid]

full boost being what? 10 or 20 psi?

So around 3500... hrm. Lemme have a thinkie thinkie.

You cant run a lot of boost due to the fuel, so its going to have to be a low boost style i think.

95ulp i still cry when i think about it!

Have you really thought about a 4-5 hours drive to somewhere else?

I mean for the sake of a good tune it might really be something to think about, i sure would be too.

[The Mafia]

hehe sorry, full boost - between 14 and 16 psi.

I am going to go to townsville and give it a good tune, but I don't know when I'll be able to make the trip. Might be heading up with a mate cause he needs to tune his beast too.

Going to be a bit of a waste of money but I guess if I want to get anywhere I will have to just do it. Surely he'll only need it for an hour to "touch it up" so hopefully I'll get away with $100 or so.

[Bl4cK32]

Questions about the RB30de that sky30 dropped in cubes - Having that low of Compression, was it a dog off boost?

<{POST_SNAPBACK}>

Your forgetting about the snot load of extra torque the motor has. You wont notice any off boost lack of performance, only more.

I can take off in second and still spin the wheels

[paulr33]

in your case it would be better to make more power on less boost due to your fuel situation so the rb30 block may be a good solution. you wont need to run as much as boost as youll have more torque and bottom end.

cubes

whats the rough price for block swap to the rb30 bloc (maybe just a quick clean and machine)

[Guilt-Toy]

This is a awesome idea - when i had my rb25 with the vg30 housing my boost did not come on till about 3500. Installed the rb30det and i could get 5 6 psi at 1500rpm and full boost at 2600rpmish.

Its a completly different car to drive.. dont have to change gears soooo late in the rpm

My suggestion.....

Don't waste money on fitting other turbo's etc just yet.

Pick up a running with good compression RB30e, don't rebuild it but simply drop your head on it. The comp ratio will drop to around 8.2-8.3:1 which will help with the 95ron fuel you are running.

See how the turbo goes then. Spool should drop 600-700rpm or so.

Thats if you can get away with doing the labour your self.

Sell off your good condition rb25det bottom end and you should break even.

Sky30 has done this... Picked up a good condition 270,000km RB30E for $50, dropped it in his R32 with an rb25 head, pushed some boost in to it via his rb20t high flow turbo and made 240rwkw, drove it like that for 1 year,  pulled the turbo off dropped on a gt35r with a .82 machined up diesel internal gate housing, dialed in 19psi and made 312rwkw which has since been running for another year. In total he's racked up 40,000km's, he only rev's it to ~6500rpm.

<{POST_SNAPBACK}>

[Cubes]

My main point was the lower comp ratio the motor (rb30det) will have is much better suited to the 95ron fuel.

BUT.. The smaller turbine housing machine up is the cheapest option. If it doesn't work well.... RB30DET, vg30 turbine back on and enjoy.

[Cubes]

I've just had a thought... hehehe

You could do this before or after you decide to play with the rb25 turbine housing in an attempt to improve spool.

You could post the turbo over to me.. I throw it on the rb30det, give it a quick wot tune that will cost me $100. Rip it off and post it back. I send you little video of its response, power made, ignition and fuel maps, datalogit logs the whole lot.

You will then know if its worth the hassle of the rb30det and so will I.

Edited December 31, 2005 by Cubes