Help me choose the right turbo

[Frank@AMS]

Another thing I forgot to mention, I saw a few people recommending re-grinding your cams. I would steer clear of this. I believe you will see great results with the stock cams.

[polizei]

Originally Posted by Frank@AMS

Andy,
As others have mentioned, to achieve your goals your looking at a GT35R with a T4 housing.

Hi Frank! Thanks for your input on this thread. I've read all I could find about what you guys did for Tony on his car - SO awesome. That car is a monster!

What size turbine and compressor housings would you recommend for my setup? Do you have a specific model number? Is that something I could purchase from AMS?

Originally Posted by Frank@AMS

The new Precision Turbo ceramic ball bearing center sections no longer need water for cooling so you'd only need to run the oil line which is nice.

Is this Precision turbo different than the GT35R?

Originally Posted by Frank@AMS

Also, I would steer clear of the air to water intercooler for a street car, its just not necessary. If you run a well designed air to air intercooler, you should be perfectly fine.

The problem is that I can't fit an air-to-air I/C under my stock Carrera whale tail. I'd like to maintain the stock narrow body look, so I'm looking into a water-to-air I/C.

Thanks for the plug on the Carrera Cams!

[Frank@AMS]

I'd recommend a turbo we call the 850R. It has a 62mm compressor wheel and 62mm turbine wheel with a .68 T4 exhaust housing. This is just a minuscule amount larger than a 35R and has no difference in spool. It also has a billet compressor wheel and the oil cooled center section. This turbo I'm mentioning is built completely built by Precision turbo in house. We have run these on hundreds of turbo kits and can honestly say that they reliably make consistent power.

[polizei]

Originally Posted by Frank@AMS

I'd recommend a turbo we call the 850R. It has a 62mm compressor wheel and 62mm turbine wheel with a .68 T4 exhaust housing. This is just a minuscule amount larger than a 35R and has no difference in spool. It also has a billet compressor wheel and the oil cooled center section. This turbo I'm mentioning is built completely built by Precision turbo in house. We have run these on hundreds of turbo kits and can honestly say that they reliably make consistent power.

Frank, is the 850R a ball bearing turbo? Also, will the .68 exhaust housing allow the turbo to breath enough at high RPM to still make 500 HP? On that note, what RWHP range do you think I could achieve with my setup and this turbo?

[Frank@AMS]

Originally Posted by polizei

Frank, is the 850R a ball bearing turbo? Also, will the .68 exhaust housing allow the turbo to breath enough at high RPM to still make 500 HP? On that note, what RWHP range do you think I could achieve with my setup and this turbo?

Andy,

The 850R is a ceramic ball bearing unit. The .68 T4 housing will be more than enough to achieve the power you're looking for. I dont think you will have any trouble making 500WHP at 1.0-1.2BAR.

[RarlyL8]

We just finished a custom T4 setup and I set it next to a standard T3 to emphasize the difference. Both of these flanges shown are split plenum. You can see how much larger the T4 is and how sizing will affect velocity and flow. You need a pretty high output engine to properly utilize the T4 flange.




This is the T4 system. Fully split system with a waste gate for each bank and 1.625" primaries will support big power.

[911st]

That is a nice one Brian!

[polizei]

Originally Posted by RarlyL8

We just finished a custom T4 setup and I set it next to a standard T3 to emphasize the difference. Both of these flanges shown are split plenum. You can see how much larger the T4 is and how sizing will affect velocity and flow. You need a pretty high output engine to properly utilize the T4 flange.

Hi Brian, I'm not trying to be a pioneer, here. Tony (YermanCars) worked with AMS to do his Carrera turbo conversion a few years ago, and he was laying down more than 500 rwhp with the headers and turbo (T4) provided by AMS. What concern would you have with a T4 as opposed to a T3? I suppose the pressure would less with a T4, causing the spool time to be pushed farther up the RPMs. But then again, he's recommending a .68 A/R turbine housing, which is a bit smaller than the .82 A/R housings that a lot of folks run on their p-cars.

I'm curious to hear your thoughts. I'll ask Tony when he reached full boost.

[Frank@AMS]

The T3 vs. T4 debate has been going on for a long time. You have to understand that you're working with 6 cylinders that produce a lot of exhaust flow. Utilizing the .68 T4 hot side, you would see almost no difference from a T3 housing in spool time. You would however see considerable gains in the upper RPM range. Also, with the new technology being incorporated, you are able to see improved spool time a bigger HP numbers. Billet compressor wheels are not only lighter, which helps quicken spool time, but they also have superior aerodynamic profiles that compress more air efficiently: less heat = more power. Ceramic ball-bearing center sections are more durable, have less friction, and don’t require coolant unlike the original traditional ball-bearing units.

[911st]

What he said!

Also, I suspect that with a T3 the tubing area cross section leading the turbine on the aftermarket headers can be quite a bit larger than the T3 inlet's cross section area.

Thus, the tubing has to taper down significantly before the turbo and very quickly.

On a T4 the taper and acceleration of exhaust gasses happens more in the turbine housing and in a more orderly manner.

This is a guess.

[RarlyL8]

It is not complicated but rather a simple matter of economy of scale. A high output engine blows a lot more air than a lower output engine therefore needs more room to do it while maintaining similar characteristics of flow and velocity.
Your 500+WHP engine can well utilize the T4 flange and larger piping in order to flow well on the top end.

[polizei]

I was just over on the Honda Tech forums, and they were saying that these new ceramic ball bearing turbos (such as the AMS 850, aka Precision HP6262) are actually considered air cooled, since the water inlet and outlet have been removed. Here's a quote from Precision:

"Precision Turbo Dual Ceramic Ball Bearing Turbocharger
These units feature an air-cooled, ball bearing center housing rotating assembly. Dual, angular contact ceramic ball bearings are utilized for maximum durability and an increased thrust load. These units require the use of a 1/8” NPT to -4 AN male fitting on the oil feed side, which can be purchased separately from Precision Turbo (PFT047-3039). At this time, we do not feel it is necessary to use an external oil feed restrictor fitting. At the minimum, we recommend the use of a -10AN oil drain flange/line. This flange can be purchased separately from Precision Turbo (PTP074-2008). Water cooling is not required on these units.
***This unit has been sealed for quality purposes. Do not remove the factory oil feed restrictor fitting, or damage may result***

I've never heard of an "air cooled turbo". Does this suggest that the turbo should see forced air? Or that an air duct to the turbo needs to be fab'd?

[polizei]

Originally Posted by Frank@AMS

The T3 vs. T4 debate has been going on for a long time. You have to understand that you're working with 6 cylinders that produce a lot of exhaust flow. Utilizing the .68 T4 hot side, you would see almost no difference from a T3 housing in spool time. You would however see considerable gains in the upper RPM range. Also, with the new technology being incorporated, you are able to see improved spool time a bigger HP numbers. Billet compressor wheels are not only lighter, which helps quicken spool time, but they also have superior aerodynamic profiles that compress more air efficiently: less heat = more power. Ceramic ball-bearing center sections are more durable, have less friction, and don’t require coolant unlike the original traditional ball-bearing units.

Hey Frank,

What turbo was installed on Tony's car when he was running the single turbo setup? In talking to Precision it sounds like there is a whopping $600 difference between the journal and ball bearing version of the 850R. Is there $600 worth of difference? When do you think full boost would be achieved on carrera cams with ball bearings versus journal bearings?