87 GNX turbo

[83rampage]

Although I'm sure this has been asked before, I did a search and didn't find much.

Found a good deal on a rebuild 87 Grand National turbo. How would this turbo work on a 2.2 hybrid with a 2.4l head/forged pistons, with a 5 speed Rampage? Maybe 15 psi boost max. (300 flywheel hp) with the possibility of more in the future. Don't really want to go Holset, but I do want more turbo than a stocker T2 Garrett.

[turbovanman²]

I think its a 70 trim in a T3 housing, stage 1 wheel. Slasky comes to mind.

[tryingbe]

Won't work without machine work. Turbine housing flanges are unique. Turbine wheel itself is unique and won't fit the standard turbine housing without the housing machined.

[cordes]

If I'm not mistaken the actual GNX compressor wheels were a little larger than the GN wheels.

[BadAssPerformance]

88_pacifica in 3... 2... 1...

[j4278h]

"Modifications included replacement of the stock turbocharger with a special Garrett “hybrid” unit that features a very lightweight ceramic impeller. The decreased impeller weight allows the turbocharger to spin up much faster, dramatically increasing performance while decreasing the turbo lag or “spool” time inherent in turbocharged engines. Maximum boost was set at 15 psi and the turbo also incorporated special dynamic turbine shaft seals in the center housing rotating assembly to reduce drag on the shaft. The turbine housing was redesigned to include a contamination trap to keep solid particles away from the turbine wheel and help prevent excessive turbocharger wear."


If its truly a gnx turbo with the ceramic wheel and cheap. Buy it and sell it to a GNX owner and just get a normal GN turbo if thats what you want.

[contraption22]

I remember a few years ago real GNX turbos were fetching HUGE dollars.

[Vigo]

If it was really cheap, id buy it and machine a stock garrett turbine housing to fit it, and keep the GNX compressor cover if possible. The compressor should be able to make 400hp at the crank if desired, but i doubt you could flow that through a stock-style .48 housing. 300whp would not be a problem, though.

[83rampage]

I checked the ad and it didn't say anything about a ceramic impeller. It has been for sale for a long time, so it probably isn't a GNX. I didn't realize they were so special.

Anyway I came to my senses and realized since I need to fab up a bunch of stuff to make the hybrid, I need to keep the exhaust more generic, and not build it for a specific oddly flanged turbo that may not even live past 1000 miles (if the rebuild was crap). Keeping it based on a T2 Garrett is a better idea since I have 4-5 sitting on my shelf right now.

Anyway thanks for the comments.

[88_pacifica]

88_pacifica in 3... 2... 1...

HA! I was sleeping at the wheel JT...

"Modifications included replacement of the stock turbocharger with a special Garrett “hybrid” unit that features a very lightweight ceramic impeller. The decreased impeller weight allows the turbocharger to spin up much faster, dramatically increasing performance while decreasing the turbo lag or “spool” time inherent in turbocharged engines. Maximum boost was set at 15 psi and the turbo also incorporated special dynamic turbine shaft seals in the center housing rotating assembly to reduce drag on the shaft. The turbine housing was redesigned to include a contamination trap to keep solid particles away from the turbine wheel and help prevent excessive turbocharger wear."


If its truly a gnx turbo with the ceramic wheel and cheap. Buy it and sell it to a GNX owner and just get a normal GN turbo if thats what you want.

I assure you this is NOT a GNX turbo and if it were, it would be at least $1K BEFORE being rebuilt. A GN turbo can support up to 350 hp and on the ragged edge, 400 hp. My recommendation would depend on what you paid for the thing. If it is less than $200 REBUILT, then I would sell it on a GN site. Any more than that, you will only break even or probably lose $$ reselling it. I would probably sell it versus trying to make it work, but it all depends on your budget...

Do you have a link to the ad or what was/is done to it(what type of rebuild)?

[Vigo]

a 60 trim or s60 t3 comp wheel will get to your power goal. You could also use a GN wheel (s70). Or, for overkill, you could do a t4 compressor side.

[83rampage]

I think getting a hybrid from TU or FWD is money better spent.

[88_pacifica]

<P>I checked the ad and it didn't say anything about a ceramic impeller.&nbsp; It has been for sale for a long time, so it probably isn't a GNX.&nbsp; I didn't realize they were so special.<BR></P>
<P>Anyway I came to my senses and realized&nbsp; since I need to fab up a bunch of stuff to make the hybrid,&nbsp;I need to keep the exhaust more generic, and not build it for a specific oddly flanged turbo that may not even live past 1000 miles (if the rebuild was crap).&nbsp; Keeping it based on a T2 Garrett is a better idea since I have 4-5 sitting on my shelf right now.<BR></P>
<P>Anyway thanks for the comments.</P>

Gotcha, I wasn't sure if this would be reconsidered later. By chance do you still have the link to the ad(for my own interest)?

[83rampage]

88 pacifica sent you a PM

[88_pacifica]

88 pacifica sent you a PM

Got it...

Thanks for the info. I am an addict for these cars.

[Vigo]

I think getting a hybrid from TU or FWD is money better spent.

Depends on your power goals. If you are ACTUALLY only shooting for 300chp, anything much bigger than an s60/stg1/.48 combo is just adding lag, not performance.

A hybrid turbo will certainly work, but a lot of them would would be major overkill for your mild power goal and you'll have the lag to show for it. Even the smallest to4e wheel has a 76mm outer diameter vs the s60's 60mm. That larger exducer diameter is going to take longer to rev up, and that's not to mention the increase in lag from the stg2 turbine or .63 housing you might buy on a hybrid.

There some to4b wheels with a 69.XXmm exducer diameter, but at that point you are basically looking at something very similar to an S70/GN wheel anyway.

[2.216VTurbo]

Got it...

Thanks for the info. I am an addict for these cars.

I thought about putting a post in yesterday and give it the 'In before Nate' title but that seemed silly and juvenile. I guess that does kinda describe me

[83rampage]

Depends on your power goals. If you are ACTUALLY only shooting for 300chp, anything much bigger than an s60/stg1/.48 combo is just adding lag, not performance.

A hybrid turbo will certainly work, but a lot of them would would be major overkill for your mild power goal and you'll have the lag to show for it. Even the smallest to4e wheel has a 76mm outer diameter vs the s60's 60mm. That larger exducer diameter is going to take longer to rev up, and that's not to mention the increase in lag from the stg2 turbine or .63 housing you might buy on a hybrid.

There some to4b wheels with a 69.XXmm exducer diameter, but at that point you are basically looking at something very similar to an S70/GN wheel anyway.

Thanks for the wisdom.

I haven't really spent much time really understanding turbo lingo, so most times when I read anything in this section it was greek.

At this point, the engine is literally a few years away yet, but I really am trying to nail down what I want and start collecting parts.

My goals have changed considerably, with only a few years ago when I got the Rampage, a stocker T1 log intake was all I wanted. That went to stock T2, and about a year ago I decided to just bite it and go hybrid.

I would love a turbo that may be a bit big so I can expand a bit, but I really don't see ever going past 300-350 at the wheels.

I need to get myself schooled keep my eyes open. All your expertise will come in handy.

[Vigo]

If you are EVER shooting for 350whp I would just bite the bullet upfront and buy something like a 50trim or s50/stg2/.63 hybrid from one of the vendors. It will be laggier than the smaller turbos you could run to make 300chp (~270-280whp), but if you are buying new you would end up buying twice to get to 350whp unless you just bought the bigger one first.

I dont know much about spool rpm but im guessing an s50/stg2/.63 on a 2.2 wouldnt spool until 3500-4000 rpm.. there are lots of people who have run them, so hopefully someone will chime in on that.

[88_pacifica]

I thought about putting a post in yesterday and give it the 'In before Nate' title but that seemed silly and juvenile. I guess that does kinda describe me

Yeah... I feel the same way when I see a Masi thread start running. Maybe I SHOULD be juvenile and use the 'In before Alan', but man I just don't hawk this site like I used to. It seems to come and go in waves...