hey guys..im currently building my true street car 67mm turbo...im wanting to go 9's, and im pretty settled on the billet 6765 but not sure wut .ar would be good..i was thinking of going with twinscroll topmount with 1.15 ar divided 6765, would this spool better than a t3 .82 ar? would the twinscroll be worth it? i kno ima have to rev to aorund 9k or more and dont mind it, but want somthing that spools a lil sooner...im shooting for around 700 whp...does anyone have personal experiece from the t4 divided 6765? i kno its not a true twinscroll turbo, but divided is pretty close... ive researched alot and havent found much..thanks guys!!my build consist of

MOTOR
84mm aebs lsvtec
manley tt rods
9:1 cp pistons upgraded wristpins
arp main studs
arp headstuds
acl race bearins
skunk2 valvetrain
supertech valves
skunk2 pro series intake manifold
70mm throttle body
gsr cams

TRANNY
b16
quafie lsd
stock gears

FUEL
stock lines for now
gonna try the new walbro 400 intank
have precision 1000cc injectors but going bigger
c16

 

Spool isn't going to be of a concern if you're "running 9s". You'll have other methods that are needed to get the turbocharger to make boost before the light turns green ON THE DRAG STRIP

If this were a street/strip car, Just stick with the T3 .82A/R and be more realistic with your goals outside of "running 9s"

 

Im very interested in this thread

 

Get a victor x manifold instead of skunk 2
And the b16 tranny no good for turbo.. Oh those injectors might be maxed out before u hit "9s" and the list might go on and on. Just my 02

 

yea i kno im needing a better fuel system, but my turbo is the key point right now because i wanna make sure i get a turbo thats gonna supply the power when i do upgrade fuel and some other things...i heard that an .82 ar t3 6765 would work fine cuz of the smaller exhasut wheel opposed to the 6768...i wouldnt rele need a t4 twinscroll to push that 6765 into the 9's, as long as i had other supporting mods of course

 

Please clarify. this does not make sense, really.

 

Negative. If he has the mph and rpm and can get it to the ground, the shorter geared trans is going to accelerate quicker. For his setup, he might need more gearing but for 700whp he can use the B16 gearing.

 

My car will be on the dyno next week with the t4 divided 6765, 1.32ar hotside, H cover. I'll post results.

 

yes im sure i can get into the 9's with a b16 tranny..maybe not the prefereed tranny for high hp, but will work...i will accelerate faster...at the 1/8 i was going 7.4 at 99 mph with 400 hp with b16 tranny..a friend with same hp with ls tranny was running around the SAME TIME but at 104 mph...please racer323 keep us updated on ur results..thumbs up!!

 

I finished my tune this morning with the t4 6765 1.32 ar.

Setup is the 6765, E85, 10:1 compression B18C(stock port), BC3 cams, s300, 2 boost solenoids, 5lb springs in 2 Tial MVS 44s, id2000s

It made great power with lower boost also
319whp @ 5psi
420@10psi
500@15psi
597@22psi
803@35psi

 

sweet made great power...wonder if that t4 divided is better or worth over the cheaper t3...t4 divided for the street is awesome and would spool good..using the t3 for drag might not be bad cuz with antilag and launching it in powerband, car would not need t4 divided...but looks good man, would like to see sum sweet vids

 

You won't really see a "spool" difference in your large 1.15 T4 divided turbine housing compared to a T3. The volute of the turbo is just too damned big. (yes, even with twin wastegates). Think about what you're trying to do with this car. You're under 3 litres (with a highly efficient cylinder head), it will just suck. Use a simple T3 in a .82A/R (since you're using the 65mm exducer exhaust wheel) and drive the car. No need to over think.

 

Nice man! Post some pics of the car and dyno. I am interested to see how well it did with that large of a housing. I also just finished installing the fuel line kit you sold me and it is awesome! I will be contacting you about getting more work from you soon.

 

why not go for the 6766? more efficent turbine wheel. But I would have went with the 1.15 housing in my opinion. On something under a 2.4L i dont think the 1.32 housing is necessary but its all dependant on back pressure.

 

1.32 A/R? Do you have any back pressure data on this car at 35psi?

 

I will try to post some pics of the graph later, I still need to get them from my tuner. Glad to hear you like the fuel lines, hit me up anytime

 

I do not have any back pressure data. According to my tuner, the 1.32 behaved in the same manner as the 1.15, no real difference in lag or power. In my opinion, the 1.15 may have been the better option. For the exhaust, I just have the 3" vband expanding to 4" for the downpipe, and it exits near the crossmember with a 4" burns muffler.

 

The turbo was purchased before the 6766 was out

and yes, the 1.32 is too big, agreed

 

Did you make any pulls in the range from 22 to 34psi?

 

1.32 is quite big, what RPM the engine spool please?

Do you think you will lose many HP with a .81 AR?

 

Not for a street/strip car no. A 1.32 is a serious size. Asking for "spool" would be silly, nor would it matter because he's looking at top end power with that turbocharger.

"spool" questions are for time attack, circuit and street use. Not for the Drag strip at these power levels.

 

Yes we made some pulls in that range, I'll have to look at the graphs to see what the power levels were.

 

Yes okay I know, but wondering if when he changes gear the RPM down in Turbo spool, because if you get a long gearbox you can down to low.
What is the maximum RPM on the car? 8900RPM? or more?

 

Not the best pic but here you go

 

what manifold u running?
I'm running an AFI top mount and the dbb 6765 t3 .83 a/r
83mm 9:1cr b18c1 with LS crank and bc stg 2 n/a cams and I made 547whp 340tq @21psi on 94oct. cams un touched but was spiking and creeping alot, I'm using a turbosmart 45mm wg with the 7psi spring. did you have any spike or creep issues? what kind of tq did you make at your 22psi?