Lost my turbos

[GJF]

Had a bad popping on high boost. I thought it was ignition related and started diagnosing. Found both E Core coils were way out of spec and replaced them with new MSD TFI units. Plenty of spark but still popping. I started thinking possibly a boost leak and started to test. I pulled off the intake boot off the drivers side turbo and low and behold the shaft play is way too much!! Looks like the impeller has dug into the compressor housing as well. So one turbo for sure is done. I still need to pull the passenger turbo and check it’s end play. The big question is since these are older technology turbos, I would have to upgrade both. So do I stay twin turbo or reconfigure to a big single? Chris any input?

[RarlyL8]

I'm not Chris but it seems like a lot of work, parts, and $$ to change from twins to single turbo. I'd have your turbos rebuilt or take the opportunity to upgrade. Either way I'd stay twin.

[Rawknees'Turbo]

Big, twin turbos are a euphemism for what your car has swangin', so best to keep the deuce!

[Tippy]

Are you trolling us???!!! GJF asking for advice having the highest hp car in the forum. What is this world coming to?!?!

I vote for twin GT35R's like Bello.

Or twin Precision 6262's?

[GJF]

Trolling naaaught! Just throwing out ideas. With the new GTX turbos being able to hit 1K with quick spool it had me thinking. Even F1 turbines with 60mm wheels sound appealing.... I still am leaning forwards the twins. I really don’t mind the fabrication if stay twins there will still be some fab work as I will probably go v-band on everything🤪

[Pat RUFBTR]

I would stay in your place with both turbos and I would put the best of the planet! V-band, hot body in stainless steel and the reel fastest possible, In brief the best turbos.

[quattrorunner]

I like twin too

[turbobrat930]

If you are used to the older turbos, you will LOVE the new GTX versions!!! You need to water cool them though.... I learned the hard way.

[Pat RUFBTR]

Thus just two small GTX3584RS on each side!

[turbobrat930]

I have one GTX3584RS on my engine... I can not imagine having two of them!!! good grief!! LOL

[Tippy]

Originally Posted by turbobrat930

If you are used to the older turbos, you will LOVE the new GTX versions!!! You need to water cool them though.... I learned the hard way.

Yeah, but doesn't the whallop, sledgehammer to the back sensation go away?

That's been my experience with newer designed turbos.

[Pat RUFBTR]

Originally Posted by turbobrat930

I have one GTX3584RS on my engine... I can not imagine having two of them!!! good grief!! LOL

I know it, this is why I made this remark!
Two GTX28RS then!

[turbobrat930]

Originally Posted by Tippy

Yeah, but doesn't the whallop, sledgehammer to the back sensation go away?

That's been my experience with newer designed turbos.

No, that is not what causes that.. going EFI makes the engine and power delivery more linear. That is why you do not get as much on/off feeling as the older CIS cars.
But, rest assured that if you were to ride in GJF's car, I would bet that you could definitely feel the G forces during acceleration!!

[Pat RUFBTR]

Mine is always in CIS and nevertheless my felt with the new turbo precision 6766 is more the same than with my former k27/29, it looks like almost an atmospheric big atmo to low rpm.

[TurboKraft]

Originally Posted by GJF

The big question is since these are older technology turbos, I would have to upgrade both. So do I stay twin turbo or reconfigure to a big single? Chris any input?

Happy New Year!
Stay twins for sure! Your engine setup is too trick to revert back to single, and the fabrication necessary to go with newer twins won't be too involved.
Email me specifics on the engine (bore x stroke, CR, cams, redline, headers size, etc) and I'll reply with suggestions.

[Ken911]

Since i now live in town i would love to come by and see that beauty some time.

[Tippy]

Originally Posted by turbobrat930

No, that is not what causes that.. going EFI makes the engine and power delivery more linear. That is why you do not get as much on/off feeling as the older CIS cars.
But, rest assured that if you were to ride in GJF's car, I would bet that you could definitely feel the G forces during acceleration!!

I don't think EFI has much to do with it. I think it's the difference between open turbine housings with low PR compressors (sledgehammers) vs divided turbines with high PR compressors (linear).

The low pressure ratio compressors put out maximum flow at low boost levels whereas high pressure ratio compressors put out maximum flow at high boost levels.

It's all in their efficiency islands.

My car has always been EFI, and the old school 60-1 HiFi (60mm) hit like a sledgehammer to your back at only 1 bar.

My Holset HX40 (58mm) and Borg-Warner S366 (66mm) don't hit near as hard even at 1.4 bar.

[Rawknees'Turbo]

Originally Posted by TurboKraft

. . .
Email me specifics on the engine (bore x stroke, CR, cams, redline, headers size, etc) and I'll reply with suggestions.

I've heard that GinormousGerry's engine is only producing 167hp (per cylinder )- hope that helps!

[GJF]

Dug in her a little more tonight. The passenger side turbo is damn near perfect. All within spec. I’m going to pull both turbos this weekend and box them up for F1 turbines and 60mm compressors. Just need to do some math and calculate air mass and flow rates off the head data.

[Tippy]

What size wheel? I looked up F1 and seems to be Turbonetics designation that covers nearly all their wheel sizes.