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Hi everybody. After installing free flowing intake and exhaust, Red Race chip from Marcus, electric chargecooler pump, etc., to my '90 SE I think my turbocharger itself is becoming a limiting factor. After some spirited pulls, my boost level gets cut of or drops, so I think my inlet temp. is getting to high from the turbocharger working to hard, eventhough my chargecooler stays cool to the the touch with my electric pump. What would you guys recommend to do to the turbocharger to get longer sustained boost? Or any other recommendations? Thanks!
 

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You may want to read some of what John Welch has written on this subject before just throwing money at something. Good stuff, and John has real world experience. Alunox markets, (or they used to ?), a double size chargecooler. Some have made their own over sized chargecooler. It's a deep subject. You can go as far as you want and pretty much spend as much as you want!

WC Engineering : Comparing Turbo Specs

Uprated Charge Cooler for Lotus Esprit Turbo
 

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Welch recommends the GT3071R, at least when I bought one 5 years ago. The new Gen2 GTX3071R is probably a better choice now that it is available. If you are still using the stock ECU, even chipped, you won't get much benefit other than faster spool though. John walked me through the order via phone while I was online ATPturbo.com. The GTX series has integrated surge protection. Yeah give him a call, its well worth it.
many owners also use the GT3071R.

PS he doesn't sell that old BB refit anymore
 

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GT3071r is the best aftermarket turbo choice for our cars. GTX3071 won’t be of any more (relevant) benefit. The GTX wheel takes longer to spool up and it’s gains are (very), marginal over the GT wheel. Specially because of our limitations on boost amount. So if you are chasing the fastest spool and the most gains GT3071R. Adding a Alunox header and twin scroll turbine with dual Waste Gates will be the very ultimate. Of course at that point adding a bigger watercooler will be the next reasonable step.

Good luck!
JG
 

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Twin Scroll option

I wanted a twin scroll, internal wastegate turbo on my '85 EFI setup and all I could find was the Borg Warner EFR 6258 unit. Boost response is fine with an Alunox exhaust manifold and 2.5" exhaust, with 10 psi (all I'm using at present) on hand about 2750 rpm. The compressor map looks to be biased a bit towards higher pressure ratios so probably plenty of headroom for those so inclined and maybe not the most efficient at lower pressures. I really don't know how the A/R on the turbine side compares to a single scroll, the numbers look bad but it spools great with the light weight wheels and ceramic bearings. Never been on a dyno, can't give any numbers, just throwing it out there for folks to look at-

The draw back is that it uses a T4 turbine flange inlet and a 3" V-band turbine outlet and would require an adapter for most manifolds and a different down pipe inlet. Far from a bolt-on unit, but did not matter to me as I was re-working everything to go from cast iron and carbs to stainless and charge cooled EFI anyway, and liked the built in BOV and boost solenoid, and a stainless turbine housing just looks cool.

http://www.turbos.borgwarner.com/files/pdf/dimensional_reference/efr/EFR 6258-G.pdf
 

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How about Garrett G25-550 or G25-660?it should be better than 3071, but the downnpipe and turbo flange have to be modified.
 

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Hi everybody. After installing free flowing intake and exhaust, Red Race chip from Marcus, electric chargecooler pump, etc., to my '90 SE I think my turbocharger itself is becoming a limiting factor. After some spirited pulls, my boost level gets cut of or drops, so I think my inlet temp. is getting to high from the turbocharger working to hard, eventhough my chargecooler stays cool to the the touch with my electric pump. What would you guys recommend to do to the turbocharger to get longer sustained boost? Or any other recommendations? Thanks!
Are stainless steel ball bearings up to the heat on the exhaust side of the turbo as ceramic ball bearings?

You are right! Ceramic ball bearings are much better.
Also, step further, triple ball bearing design takes care of the axial loads. https://www.compturbotechnology.com/turbo-technology

Stay away from ChiComNetics = non-reliable duplicates, sub-standard materials.

See one of my older threads on the subject. Stay away from resalers, deal directly with Manufacturers, like Turbonetics, BW, Garrett or Comp Turbo.
Insist on 2 years warranty.

Here is something to ponder: Comp Turbo is the most innovative turbo maker, always on the leading edge of technology https://www.compturbotechnology.com/technology

https://www.compturbotechnology.com/our-ct-r-line

P.S. It is prudent to discern between the mere hear-say sound bites and actual empirical impressions of the end user!
 

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Twin-Scroll Turbo options (new)

I wanted a twin scroll, internal wastegate turbo on my '85 EFI setup and all I could find was the Borg Warner EFR 6258 unit. Boost response is fine with an Alunox exhaust manifold and 2.5" exhaust, with 10 psi (all I'm using at present) on hand about 2750 rpm. The compressor map looks to be biased a bit towards higher pressure ratios so probably plenty of headroom for those so inclined and maybe not the most efficient at lower pressures. I really don't know how the A/R on the turbine side compares to a single scroll, the numbers look bad but it spools great with the light weight wheels and ceramic bearings. Never been on a dyno, can't give any numbers, just throwing it out there for folks to look at-

The draw back is that it uses a T4 turbine flange inlet and a 3" V-band turbine outlet and would require an adapter for most manifolds and a different down pipe inlet. Far from a bolt-on unit, but did not matter to me as I was re-working everything to go from cast iron and carbs to stainless and charge cooled EFI anyway, and liked the built in BOV and boost solenoid, and a stainless turbine housing just looks cool.

http://www.turbos.borgwarner.com/files/pdf/dimensional_reference/efr/EFR 6258-G.pdf
I was looking for this post for a while. I'm glad I found it.

This is FYI only: Great article explaining advantages of the twin-scroll turbos

https://dsportmag.com/the-tech/twin-scroll-vs-single-scroll-turbo-test-the-great-divide/

https://zilvia.net/f/showthread.php?t=460807&page=8

IN ADDITION: there is a new T-S BW Variable Scroll turbo on the market (although too "big" for our Esprits)
EFR7163-J(VTV)
It may be too big for street, but it suppose to have much better low end performance!

This technology (variable turbine geometry) has been around in the OEM and diesel industry for years, but never had a huge presence in the aftermarket.

What does it do?
When the valve is open, it forces exhaust gases/pulses into one of the scrolls of the turbine housing.
When the valve closes and returns to center (after peak boost is achieved), it allows exhaust gases/pulses to free flow and utilize both scrolls of the turbine housing ? much like any current twin scroll setup.

What does it yield?
By effectively reducing the turbine housing A/R when the valve is closed, you can expect quicker spool and TQ gains at low engine speeds.
There should be no downsides or losses at higher RPM's as it retains same split pulse volute design of current EFR turbine housings.

For 4cyl Esprit EFR6258-G map looks right on the money.
https://www.jegs.com/images/photos/100/156/156-179150turbomap.jpg

If you want to run higher boost EFR6758-G is right for you
https://www.jegs.com/images/photos/100/156/156-179388turbomap.jpg

.
FYI: Sale here. https://www.turbokits.com/Turbo_Cha...8_T4_.80ar_Twinscroll_IWG_Turbocharger/11455/
 

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Integrator
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You are right! Ceramic ball bearings are much better.
Also, step further, triple ball bearing design takes care of the axial loads. https://www.compturbotechnology.com/turbo-technology

Stay away from ChiComNetics = non-reliable duplicates, sub-standard materials.

See one of my older threads on the subject. Stay away from resalers, deal directly with Manufacturers, like Turbonetics, BW, Garrett or Comp Turbo.
Insist on 2 years warranty.

Here is something to ponder: Comp Turbo is the most innovative turbo maker, always on the leading edge of technology https://www.compturbotechnology.com/technology

https://www.compturbotechnology.com/our-ct-r-line
Comp Turbo has a great technology, but their sales department is very difficult to deal with. In last 5 years they went trough 3 sales reps and...
they still suck!
 
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