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Posted: Tue Sep 04, 2007 7:23 pm
by rodavo
Its been a while since I last posted so heres the latest news....

Motec has been on for over 6 months now and is going great. So good to be able to tune absolutley everything about the engine. I am running a wideband air/fuel ratio meter and have done all the tuning myself. Needs to go on the dyno to do a little bit of fine tuning but being able to log in the Motec makes it alot easier to tune on the road.

I blew my VF8/Piazza turbo about 2 weeks ago. Turbo was just old and had so much shaft play that it could not be rebuilt. The centre section of the turbo was ruined. Couldnt find another VF8 quick enough so took the leap and after talking with GCG turbos have upgraded to a custom turbo. Its a Garrett GT28RS (disco potato) centre and wheels then GCG manufacture custom adapters to mate the VF8 compressor housing and Piazza turbine housing to it so the end result is a ball bearing turbo which bolts straight onto the standard piazza exhaust manifold. With a bit of fiddling with the oil feed and water lines the turbo is a direct bolt on.

[thmb]http://ozisu.com/photobucket/DSC00829.JPG[/thmb]

[thmb]http://ozisu.com/photobucket/DSC00823.JPG[/thmb]

[thmb]http://ozisu.com/photobucket/DSC00828.JPG[/thmb]

The result is very impressive. The turbo has totally changed the engine characteristics. It pulls so hard in the midrange now, and once I get the 3 inch dump and and exhaust on it should go well up high as well.

Havent had the car on the dyno yet, waiting for some time to finish off my exhaust and start on the intercooler project.

Dave

Posted: Mon Sep 10, 2007 11:07 pm
by Bugle
Does it matter much not having the original disco potato compressor housing? Couldn't have been too hard to adapt the intake piping to it?

Posted: Tue Sep 11, 2007 12:09 pm
by rodavo
No, it probably wouldnt have been too hard to use the disco compressor housing, the only problem I can see is the clearance between the compressor housing and the exhaust manifold cause the VF8 goes very close to hitting it at the moment. Also would have to modify the mount for the wastegate actuator. Plus there would be an extra cost on top of what I paid to then get the housing.

GCG said that the way my turbo is now it would be rated at around or just under 300hp. Thats a bit of a guess though. The surprising thing is the piazza turbine housing is quite large even though it doesnt look it.

Posted: Thu Sep 13, 2007 7:45 pm
by Bugle
Oh ok thought the turbo would've come with the housing already and cost more to adapt the IHI one to it.

Yeah the original turbine looks pretty big similar in size to the Skyline T3's, compressor is tiny in comparison though.. I probably could've made an adaptor myself to get the T3 mated to a standard exhaust housing rather than go to all the trouble of making a new manifold!

btw how was the all holden day?

Posted: Thu Sep 13, 2007 10:11 pm
by rodavo
Yeah, you can actually get the turbos without the compressor and turbine housings because you get to choose which size housings you want when you buy a new turbo.

The All Holden Day was really good, heaps of cars, over 700 they reckon. I didn't see another Piazza there and when I drove in I got a fair few looks from people and I was asked if it actually was a Holden when I was entering. Alot of people came and had a look at it, the most common comments were "Haven't seen one of these in years" or "what is it?". Pretty funny to watch people expressions as they try to get their mind around it being a Holden!!!

Posted: Thu Sep 13, 2007 10:16 pm
by rodavo
Also forgot to mention the other upgrade that I have done. I am now running a Procomp CDI ignition unit which gives huge spark. Worthwhile upgrade for under $300 and makes then engine run heaps smoother and start better. Should also be able to see a power improvement in the higher revs when I test it on the dyno.

Posted: Sat Sep 15, 2007 5:56 pm
by Bugle
hehe were you running Isuzu badging to confuse them even more? I think i'd have to put all the Holden stuff back on if I went.

I thought the stock ignition gave a pretty good spark, I once started the car and was fine but went to take off and it started dying. Look under the bonnet and i'd left the lead unplugged from the coil sitting maybe 5cm away from the top of the coil and the spark was jumping the gap! But the only car i've compared it to is the Gemini with shitty points which won't fire if there's high humidity..

Posted: Sun Sep 16, 2007 8:22 pm
by Rodeobob
How much did the turbo set you back???

Ive got my eye on getting one of these turbos.

-->Link<--


Is there anything that can be done about the large pics??? makes the thread hard to read.

Bob.

Posted: Sun Sep 16, 2007 11:01 pm
by rodavo
That looks like a good turbo for the price. I wonder what that compressor housing and wheel is from? Other thing to watch out for on that turbo is if the wastegate port has been increased in size. If it the standard Piazza size then it might have issues with over boosting with the larger wheel and housing.

I paid $1400 for mine all up which was more than I wanted to spend but was the quickest way to get the car back on the road as it is my daily driver. Cant complain about the performance though!

As far as the pics, I am not sure how to reduce them, I think someone else on this forum reduced them last time for me? Not sure.

Posted: Mon Sep 17, 2007 5:30 am
by Rodeobob
Its all good, i just slide the thing across down the bottom.


I can do what you did which is pretty much whats on eBay i think. I picked up a good RHB5 and manifold off a guy on eBay. I spied what it was, he thought diesel, i knew different. i think i paid $240. Its a mint turbo looks like its done stuff all work, manifold and dump came with it.

Ive already got a Subaru one here i bought of someone ages back. Its the subaru core with the piazza exhaust housing on it but the other two came with it as well. I didnt have the Piazza shaft to use the exhaust wheel for a better fit. I was going to put it on my good car but then i got the new turbo. With that much exhaust clearance i doubt it would have worked that good.


Now i can pull the comp wheel off the good turbo ive got and put the Suby wheel and housing on it.
How daft am i?? I only just put 2 and 2 together then. Ive had the other turbo for at least 2 months. Doh.


How do your rekon it would go on a bigger motor??? 2.3L or a 2.6L.


I definately like the the way the plumbing works on the subaru. The way you did it. The way the Piazza is done is stupid.


Bob.

Posted: Wed Sep 19, 2007 1:31 pm
by Rodeobob
I fixed the pics, they are thumbs now.
Bob

Posted: Tue Mar 03, 2009 5:26 pm
by speedracerles
Wow I know this was an old post but I wanted to know if i just buy the disco potato turbo with all the things that I would need , would I just be able to bolt it right on? I mean with some playing around with it. I know someone who is getting reed of one from one of there old projects and they would sell it to for cheap. I just need to know if it is something that I should be looking at.... Thanks :prayer:

Posted: Tue Mar 03, 2009 8:13 pm
by rodavo
The standard disco potato wont bolt straight on. GCG turbos did alot of work to adapt the IHI housings to the Garrett centre. If you gave them the disco potato and the IHI Piazza turbo they will be able to do the job but I am not sure what they would charge. Would be worth talking to them.

If you want to make an adapter plate for the exhaust manifold then you could probably use the standard Garrett but still need to play around with the oil and water piping to the turbo to make it work.

Posted: Wed Mar 04, 2009 2:59 pm
by speedracerles
So what turbo is the best set up for this type of job, Im just trying to bolt on something thats going to give me a little bit more power. I would like to have a bigger turbo installed but I dont know the ends and out to go about doing such a job on my own....

Posted: Wed Mar 04, 2009 5:31 pm
by wedgenut
be careful you don't end up going backwards, if teh turbo is too large you could get shocking lag and poor top end performance. Mid range should be good but you may need to upgrade the Intercooler and injectors. You can't just add more blow in isolation. Go make friends with someone who has already made all the mistakes and learn from them or throw a bucket of money at a specialsist tuning shop. I prefer reliability over a hand grenade any day.