I was discussing these Turbos with a friend of mine and he said that these GT35 Ball Bearing Turbos will spool at 2500 rpms with a 1.06 AR. My question is why aren't people using these Turbos. The large AR will help to prevent backpressure and the ballbearing characteristics allow a 20% quicker spool time. Just thought I would pose the question. What are people using for ARs with ballbearing turbos? These also come in an .82 AR.

 

Aren't those what Incon used on their stage one kits? I am not really sure of the AR though.

-Geoff

 

White_Hawk - Is your 451hp with the Powerdyne?? Also, is that from Gregs mustang Dyno?

just curious

Great numbers!!

 

Price and availability. They used to be about twice as much as a comparably sized T series and were hard to get. As people start using them price will drop and the lead time won't be 3-4 months.

Gary

 

The wheels, both compressor (2.41/3.22) and turbine (2.45/2.68), on the GT35 complete turbocharger assemblies (600+ hp) are a tad bit larger than the incon turbos were. I think you would be lucky to see full boost around 4000 rpm with the 1.06 A/R and maybe 3500rpm with the .82. I see full boost at 2600rpm with the standard incon turbos, compressor (2.09/2.80) and turbine (1.85/2.12) and .86 a/r on my car and have seen full boost at 2200 rpm on a car with .64 a/r. The larger Incon turbos, compressor (2.17/3.00) and turbine (2.11/2.22) were closer to 3000rpm with .64 and 3500rpm with .86 a/r.

 

You say you see 2600rpm spool with Standard Incon Turbos, with a .86 AR. Are you running twins? Also the DUAL ball bearing not the single ball bearing have a faster spool than the standard journal bearing 20% faster. So with twin turbos and twin ball bearing GT35s with 1.06 ARs I am wondering if boost would be present at 4000rpms? I was really hoping to hear from somebody who has experience with these Turbos...I think the Turbonetics are a Single Ball Bearing which is not as efficient as the double ball bearings. I want to know if these things will make boost at 3000rpms and not be fininshed until at least 6500 rpms. I am dismayed at all these turbo graphs I see where the boost and power is only made from 2600-5500rpms and then it all disappears. A properly sized Turbo matched with the correct plumbing should make boost and power to max rpm. What do you think? Maybe the Garrett tech was just trying to make a sale. I was thinking GT30R's with a .82 AR originally.

 

Yes, all Incon turbos are garrett dual ball bearing turbos. The GT35 you are looking at is just a larger variant. The relevance of the rpm and boost is not as much of an issue as what hp you are at. The GT35 in twin format will produce upwards of 1200-1400hp depending on A/R and they really do make that much power. The standard Incon turbos were 760-800hp, depending on A/R, and the upgraded incon turbos were 950-1000hp. I don't think you will have a problem with the GT35's at 6500rpm unless you happen to max the turbos out at 1400hp at 6000rpm.

 

I have the standard Incon's.

I see 5psi by 2,200, and 8psi by 2,400.

My power graph looks exactly like stock except for the 3/4psi spike which, on the dyno, occurrs in the 3,500 ish range. If the rollers put more load on the car, this would not happen that high.

You would not be dismayed at the graph. Once boost settles in, it's not distinguishable from stock...(stock cam)...unless you look at the numbers.

 

Incon Stage II actually used GT25R Wheel.

 

The incon stage one and two both used the same turbo which is based on a GT25 cartridge. The stage three "larger turbo" kit used a GT30 based cartridge as listed above.

 

So maybe a set of GT30R with .82 AR is the real deal. I don't think anything in the stock drivetrain on F or Y Body can handle 1400hp. Just was curious about helping my friend match the right Turbo that builds boost about 30% of redline and holds through to redline 6500rpms (would allow to hold 4th through the 1/4 on a 28" tall tire). I don't want to see any back pressure or running out of Turbo complications. So it sounds more like a GT30R with a .82 AR.

 

Don't belive everything you hear. Going from T66's to ceramic dual BB T66's on my old car only sped up spool by about 300 RPM's.

 

So is it consensus that the 1.06 AR is to large?

 

What power range is he looking for?

 

Thinking about 750rwhp +/- 50rwhp. Looking for boost about 2800-3300 rpms.

 

GT30R's are very nice and should spool very nicely. I had a set of them come through, and they were impressive units. Big output for the size.

Jose

 

I'll be able to report on the on the GT series turbo very soon now. I am still using a single but am installing a Garrett GT42R series turbo with a 1.16 AR housing. My new motor is now a 9:1 compression 389 (nice famous Pontiac number ) with a 4" bore with a Callies 3.875 crank. The car should make great power and I'm very interested to see where boost comes on. ARE is also building up a 355 LT1 with a GT35R turbo, smaller but similar setup as mine.

As I said in another post the new kit uses forward facing headers, retains the AC and fit isn't an issue on either car. Both kits use stainless exhaust and aluminum intake and should make for a sweet kit

 

damn....that GT42 is going to rock in your car....I would think with the AR being 1.16 that the car will see full boost by 3500 rpms.

 

I take it your using the T6 flange version, or did you opt for the T4 flange version?

Jose

 

I'm using a 4 bolt, tangental housing. Does that answer the question, because Garrett didn't specify T6 on the specs?