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all of this on a stock bottom end?

I'm running 14psi.. Tuner says there is a big difference between 14 and 19 psi, and like 50rwkw worth, but there is also a difference in the bottom end staying together and going bang...

Got me scared...

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well, I have a heap of logs that you can analyse.

All recorded in datalogit, and easy as

Open FC-Datalogit

Window

Mapwatch

File-> Open

Select one of the log files

Log_20051219_1747.txt

Log_20051219_1752.txt

Log_20051219_1756.txt

Log_20051219_1757.txt

Log_20051219_1758.txt

Log_20051219_1759.txt

Log_20051219_1801.txt

Log_20051219_1805.txt

all of this on a stock bottom end?

I'm running 14psi.. Tuner says there is a big difference between 14 and 19 psi, and like 50rwkw worth, but there is also a difference in the bottom end staying together and going bang...

Got me scared...

I wouldn't worry too much - it's not so much the boost that kills engines it's pinging. It'd be interesting to back off the timing a bit, make sure the AFR's are right and do a few power runs with more boost.

You'll definately have to run more boost if you want to make some decent power - there's a bloke on these forums with a gt30 internal wastegate on a rb25 - I think the one with the small rb exhaust housing who was making over 250rwkw with the stock bottom end. (horsepower in a box kit)

Now he's installed cams and is making more - all depends on whether you want to take the risk - if mine goes bang I'll go a rb30 bottom end.

My adjustable nismo FPR is set at 45 psi at idle.

How does the car drive? Does it feel faster than when it had the stock turbo?

Maybe the dyno wasn't reading right?

Cheers

well, the car drives ok...its very laggy. Doesn't come on hard until 4000rpm, which I am not impressed about.

Its a Stock sized ex housing for hells sake!

I don't really know.

Car pulls A LOT harder up top, as the dyno figure shows 460nm of torque or about that. I don't have the chart because the tuner reckons his printer is buggered. I think his whole set up including him is buggered....

I thought I posted again but it must have got lost .

That TO4S wheel is probably not helping much but the GT30 turbine in a non native VG30 housing is almost certainly causing some restriction . That housing was intended for a much smaller ceramic turbine and in low boost form (7-8lbs?) good for 190Kw on a 3L V6 . I know the high flow makes more but its 76T XXXX turbine is of lower tip height than the 84T GT30 and somehow works . Its 71mm XXXX compressor is smaller than the 76mm TSO4 so it is better matched to its turbine . Actually for its age its compressor is quite efficient .

I can't emphasize enough that its the TURBINE/housing combination that drives a turbocharger . The best car in the world is stuffed if the engine is a dog and the same is true for turbos if the turbine/housing combination is not sorted . This is always the hardest part to get right and often OEM mounting flange / integral gate convienence brings it all undone . This is why firms like HKS go to the trouble of making model specific kits that bolt on . Yes its expensive but it BOLTS in reasonably quickly and easily and is generally a known quantity . Mafia , I dare say you found out the cost of many fiddly one off bits adds up to a tidy sum and on top of the turbo price could be reaching up to that of a complete kit . I think you're choices are limited to fitting an exhaust housing that works or changing the turbo for something more suitable .

At the end of the day even if you can get around the detonation dramas its doubtfull if it will reach your power goals . It sounds like the exhaust restriction is causing heat probs within and detonation . An easy way to find out is to connect your boost gauge to somewhere on the engine side of the turbo (exhaust manifold or turbine housing before the turbine) and check the pressure . Don't be surprised if its double or triple that of you're inlet manifold pressure under boost . Waste gates generally "blow open " because exhaust manifold (turbine inlet) pressure is much higher than boost pressure . If you have three + times the boost pressure acting on the flap valve and one times boost pressure acting on the actuator I know who's going to win every time .

Out of time again , cheers A .

Before I give my opinion on that we need to know what the original goals were .

Where you wanted it to go from and how much top end .

For fast road you probably want it to go from ~32-3300 rpm and have good mid range torque .

GT30 turbines really need GT30 turbine housings to work properly - the nossle area of the housing needs to suit the exducer tips of the turbine blades . Garrett make turbine housings to suit in .63 / .82 / and 1.06A/R - external gate T3 flanged . As far as I know only HKS make propper integral gate GT30 T3 flange turbine housings that work . These are intended for HKS's bolt on version of the real GT30R , they call it GT3037 Pro S but it uses the identical cartridge (700177-7) as the real GT30R (unit no 700382-12) does .

I think you have 4 choices here as usual based on cost .

1) Buy and fit the HKS Pro S integral gate housing in .68 or .87 , it would need

the HKS or copy dump pipe to suit .

2) Buy/fit the HKS cast manifold and external gate and use a Garrett housing .

3) Buy/fit HKS 2835Pro S or 3037Pro S kit .

4) Get your original turbo Hi flowed and fit it back in with the standard fittings .

People say it works well with the VG30 housing but you'll need another as your

one is machined out differently but check it out anyway .

I found out the hard way years ago that expensive one off bits are a pain because they only suit one combination and if it doesn't work the doughs already spent .

Yours is an easy situation to get into and an expensive one to get out of - how expensive will depend on what you can sell the bits you don't want for .

Can the moderators make this a STICKY . Buy Garrett Ball Bearing turbos with 7 bladed TO4S compressors at your own risk . Nothing about these compressors is desirable and the results are bad . A propper version will have GT (Garrett Technology) turbine AND compressor and an "R" or rolling element ball bearing cartridge . The turbine housing should be a match with the turbine in one of the available A/R's .

Mafia - I had a VG30 rear housing into a rx7 core and rear wheel with a .60 at t4 front and the max power i was able to get was about 240rwkw.

The rear housing would get extreamly hot and it was just detonating on that power. We tuned it down to about 225 or so rwkw and it settled down a fair bit - this was on a rb30det.

Boost would come on at 1800rpm to 2100rpm and would fall off up top big time.

The VG30 rear housing is a good upgrade for the stock turbo but its not going to bag you alot of KW. (apparently they are .71 but when you start grinding them out to put a bigger wheel in them the AR ratio gets smaller and it becomes restrictive) i had to keep the boost at 9 or 10 psi to stop detonation and make the power - used lots of timing.

I have sold my turbo to a guy who has a relitivly stock car and got a top mount manifold and a GT3540 with ext gate. Car is not finished yet but it may be done by the end of the week.

Since the 230rwkw with vg30 housing i have got

forward facing plenum mod

top mount (ebay special with 10 hours spent on it to get it acceptable)

gt3540 .82 rear housing 70 front

genuine tial wastegate

Nismo 740cc injectors

Q45 AFM

300x600x100 fmic

Il let you know how i go with it once its going - but im expecting at least 300rwkw or more.

Man, this is a sad story about a mod that should have been THE duck's guts with the effort you've gone to.

discopotato03 given that these guys have both done a hybrid using VG30 housings and both ended up with what appears to be a choke in the turbine area due to the flow capacity of their compressors, can you see what similarity they have in the CHRA?

hhmm... Just thinking, I have a few ideas to try and make this a little better.

First I am gonig to install a spring on the wastegate flap to try and create a bit more tention, to see if its blowing open.

Second, I am going to do what I have been meaning to do for a while and get a better boost controller than a bleed valve - The powerFC boost control kit. My mate set up the Link boost control kit and his boost was hitting way harder, and much better and earlier. You could even hear the turbo work a lot harder.

The exhaust housing: Do you all think I should get the garrett equavilent .63 internal gate housing, or go a step bigger and get the .86 internal garret housing?

I'm a little confused. Will the specs of the turbo help? I'm going to get them and post them up

Edited by The Mafia

try pricing a HKS exhaust housing from greenline.jp or racetep.com

ps. Precision Turbos in the USA apparently also make internally gated GT30 exhaust housings.

Edited by wolverine

I'm not going to mess around with the VG30 now that I've seen a few have issues making close to 270-280rwkw.

GT30R + .87 HKS Turbine housing + HKS Cast manifold is my decision... for now lol.

I'll be happy with 270-280rwkw, more than enough in rwd 1300kg 3ltr mid range monster. :blink:

The GT35R would be nice BUT with the .82 it appears with cams its pretty much all in by 3500rpm. I really want it in by low 3000's.

Even if the HKS turbine housing ends up costing as much as an external gate setup I don't care, I want it looking stockish with a decent manifold (HKS Cast) and without a manifold and external gate hanging out everywhere.

Such a Pitty HKS didn't place the external gate flange underneath instead of on top.

Edited by Cubes

Ok Mafia has given me the numbers he's seen on the ID tag fitted to the core of this turbo unit.

He's read it as 700177-5011

Looking at available literature, I suspect it will actually be 700177-0011

check this site which gives specs:

http://www.turbomaster.info/eng/applications/bearings.php

For that CHRA number, it should therefore have

Compressor 76mm T04S, 55mm inducer, 52 trim

Turbine 57mm GT28, 54mm exducer, 90 trim

As previously noted, he has a 0.7A/R comp cover. Not sure of the specs on the cover (read: nozzle/tail sizes), but it clearly has a bloody big bell-mouth.

Hot side is the VG30 housing for which there have been a number of "guesstimates" on the A/R. Fact: nobody's (on this board that I'm aware of)actually sectioned either a VG30 housing or one from a RB20, 25, 25 Neo, so the A/R of each is not known. It does seem fair to say that the VG30 IS larger, but by how much we don't kow.

What would be worth knowing is whether anybody has easy access to a VG30 or 25 Neo unit so that they can accurately measure (using verniers) the size of the turbine impeller at the inducer and exducer. A reasonable computation of the wheel size can be made (max diameter + trim) so we can at least see what was matched by the engineers to that housing.

Until that is known I would not like to draw any conclusions or make assumptions about flow restrictions with Mafia's combination (even if they may be correct). :)

cheers

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