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Discussion Starter #1
This will be an interesting thread....

Got my motor basically all wrapped up (3.4L + VVTi + 10:1) time to pull the trigger on a turbo setup and I want to experiment with a big twin setup as I'm that kinda guy that likes to think outside of the box and single setups just don't excite me visually.

Twin Turbo setup will be a twin t4 with QSVs, so my turbo options are ones that must be T4 divided, and brand preference is Precision only.

As far as my goal with the car, I would like a turbo setup that can provide as much HP as possible without needing nitrous to get the car to move out of its way on the street/highway.

Precision turbo options I am considering:

Twin 6062
Twin 6466
Twin 6870 (yes I did go there)

The three of those can all be offered in .84ar divided T4 housings and SP compact compressor covers, so essentially they are all the same physical dimensions for fitment purposes.

The 6266 I left out as I feel that if I am going with a 66 back wheel, mine as well go 6466.

The 6766 I left out as research proves a 6870 to spool nearly identical to a 6766. Even did some research digging up dyno threads on 4cyl forums such as evos and Hondas sine my 3.4L will essentially become a 1.7L

After researching a lot on 911 turbo forums, plenty of 3.6L 911s making great power/spool with low 60mm range turbo setups. Mind you they are not using quick spool valves either which from my personal experience with QSVs is that they absolutely rock and work as advertised.

I got the twin 6870 idea from Amit's big red build from back in the day. That car was a 3.4L with 9.5CR, but no vvti, no QSVs, and old school PTE 6765 turbos which I would bet the house that a newly designed 6870 will spool identical or faster.

The 6062 option would be a safe bet, and the one I am leaning more towards, as correct me if I am wrong, the HKS GT3040 twin kits found on supra builds back in the day are 60mm compressor inducer turbos, and those worked well on several cars on here.
 

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It's all about area under the curve not just peak ... I would lean to the smallest you have selected
 

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I'm curious what could be done with twin efr 8374's. Optional built in wastegates could save you some space maybe. I think those turbos are in the 62ish mm range.
 

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Good luck with your twins project! Of course I'm also a fan of twins though my tastes run different than yours.

^ there's a few twin EFR setups built or being built now that look very interesting to me, too.
 

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I used to run twins and loved them. The sound and the powerband was unlike any car I've had. With that being said I would run the smaller turbos on the side of the spectrum you're looking at. They are going to make dumb power you will still be able to use on the street and make it in a meaningful way.
 

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you could even look into twin 5862's.
Couple questions
-How high are you planning on revving this engine?
-Is there any sort of power goal in mind?
 

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Discussion Starter #8
Plan on revving no higher than 8.5k rpms

Power goals would be 4 digits, anything over 1000whp is a plus. 6062 seems like the ideal fit for that power goal, 5862 would probably spool the same as 6062s as its the same exhaust wheel, similar to 6266s vs 6466s.

Im thinking two 6062s will make 1200-1300whp all in with respectable response
 

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Plan on revving no higher than 8.5k rpms

Power goals would be 4 digits, anything over 1000whp is a plus. 6062 seems like the ideal fit for that power goal, 5862 would probably spool the same as 6062s as its the same exhaust wheel, similar to 6266s vs 6466s.

Im thinking two 6062s will make 1200-1300whp all in with respectable response
Man,3 out of my 4 turbocharged cars are twins and I love it.
The most exciting is my 3Rotor with 2 PTE6063.its a blast.
 

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I love my 6466... I can only imagine two of them.

Although my concern is having lag with such big twins. A friend of mine has an HKS twins setup on a stock bottom end and doesn't get good boost past 5500rpms. I know it's apples to oranges but still..

If I would go twins, I think the best pair would be the new gen 2 6062.. or max gen 2 6266...

Ryan
 

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No need to rev a stroker to 8500. I made 1110 whp at 7200 rpm 12 years ago almost to the day (SILV2004). This was/is a non vvt-i motor, with stock compression on gas (C16), twin HKS 3240s mounted on an HKS 3.4L stroker. As I am sure you know, the whole idea behind a stroker is to make power more accessible. You have a high compression vvt-i motor and, I assume E-85. All of these things should make the power you make very accessible. You already have higher piston speeds and a poorer rod/stroke ratio with the stroker. No need to exacerbate those issues with revs sure to be well past your power peak, assuming you go with the smallest turbos that will allow you to meet your power goal.

Ken.
 

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Have you taken a look at the new Garrett GTX29xx series? Might be worth taking a gander at...the 2967 is good for 500hp...
 

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My prediction more and more will be looking into building cars with twins especially after Twins Turbo twin efr car was off the charts with power all around (iirc 1000rwtq?)
 

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Love hearing your considering this! I too would like to go this route but on my built 3.0, VVTi, blah, blah, blah... I'd lean towards the usable power end and more street friendly, 6062's or 6266's.

Subscribed!
 

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Imagine that twin EFR kit, with the SupraSport(?) head they just released....OMG
Or 2-5yrs down the road when someone steps up and makes a taller deck billet "street" block 3.6L paired with arnout's billet head and twin efr's running around on E98. At that point I think the getrag trans will be in the danger zone unless some new options come out for it as well like albins
 

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For reference, the HKS 2835 twins had 51mm compressors, and used very small T28 exhaust housings. True, turbo technology has come a long way since.

Even the smallest one's you listed (6062) would need T3 exhaust housings. You have 1.7 liters spooling each turbo. No way around at least some lag.

Won't this be like the 5th different turbo setup you used in only a year and a half you've been a member here?

Al
 

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For reference, the HKS 2835 twins had 51mm compressors, and used very small T28 exhaust housings. True, turbo technology has come a long way since.

Even the smallest one's you listed (6062) would need T3 exhaust housings. You have 1.7 liters spooling each turbo. No way around at least some lag.

Won't this be like the 5th different turbo setup you used in only a year and a half you've been a member here?

Al
I don't believe the HKS GT2835 used T28 housings. They were T25 flanged, but I believe they were more T3 sized, as HKS' T2x housings were internally gated. I could be wrong though
 
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