If given the choice between twin T3/T04B stage 3 with .82 AR turbos or GT30R's with .81 AR which would you choose? Keep in mind that price is an issue. The GT's are about $1200 more. Looking for up to 800rwhp with forged 402. I know the GT's should work well but would the T04B's?

 

The GTR Garrett turbos are dual ball bearing and will spool up faster. But they are also water-cooled. So you will have to plumb for that also. But that would be my first choice.

 

I've always been a big fan of Turbonetics, bought well over 100 T3/4 hybrids when my shop was open.

The above post is true but you can call Turbonetics and they will give you T3/4's that can be water cooled with any trim size you want.

I would go with Turbonetics and ask them to cermaic coat them as well.

 

I wouldn't bother with the water cooling. WIth a 402 it's not like you have to worry about lag. I agree about the ceramic coating too.

 

Not going to water cool.

So do you think those actual turbos (T3/T04B stage 3 .82AR) are big enough? Or are they going to choke it off more than the GT30R's?

The turbonetics turbos are going to spool really fast as well, but they will have a more abrupt spooling characteristic.

Looking to run about 14-15 lbs of boost max.

Hey Jay,
What turbos are you running? - or is that still secret

 

Put T350 (stage 5) or p-trim wheels into those turbines and use 60-1 hi-fi (if space is a concern) or full sized 60-1 or 62-1 compressors...cheap, and plenty of airflow for a moderate boost level 402.

 

Manifolds and space are setup for this style of turbo so my choice is between the two.

Keep the input coming

Thanks.

 

No secret they are Turbonetics T3/4 Hybrids. I don't know the trim size but it's larger than 58 trim I can tell you. George from TTi wouldn't tell me the trim size!
PM Phil AKA RoadRebel and he should let the cat out of the bag.

 

A lot of testing was done with different turbo combos on the X kit - I don't blame them for not wanting to advertise the recipe.

Mark

 

I agree Mark but it's real easy to figure out if you want to take a turbo apart.

I do not care to do such as this project is over.
Time to move on to the next one.

 

Not that ideas are not taken here and then claimed as there own.

That's why the great shops like LPE, MTI, Cartek, Vette Doctors and Synergy are now tight lipped.

 

You have no clue how many PM's I've gotten from people to shoot them some pics of one off things ECS did on my car.

 

It's one thing to be helpful and answer some tech questions, but it's quite another to give away the store. I'm surprised the vendors give away as much as they do considering how competitive the performance market is.

Mark

 

I have to agree with you Mark

Dan

 

Agreed the water cooling was to extend the life of Turbos by cooling the oil after shut down, and thus avoiding "coking". It follows the same logic as Turbo Timers. Although synthetic oil can "coke", it far exceeds the temperature at which organic oil will "coke". Not saying it isn't good to have water cooled bearing housings...its just not necessary.

In a T3 size turbo, there is no doubt I would go with a GT35R with a 402cid or a GT3031R with a 346cid. I would most likely take the GT35R with a .81 AR on the hotside with a 402.

However you can save yourself a lot of money and go with a 60-1 from Turbonetics. You can buy 2 turbos for the price of 1 GT series and get virtually the same performance...and you don't need liquid cooled bearing housings.

The 60-1 is basically what Paul is running in his Z06 if I remember correctly. It is the same wheel that is in my T4 PT52s.

Let me suggest something about spool up. I can run my car for the most part NA under 2500rpms. If I even try and launch at 2300-2500rpms on 335 size street tires...not even in boost will spin my tires off. I prefer to have my power from 3000rpms on up. It allows me to drive the car with traction and get it moving as the boost develops...making wheel spin managable. It still will burn the tires off but I have complete control and drivability on street rubber. This is also a benefit at the track. While the majority of my track time over the years has been NA/NOS, I never launched on slicks unders 3000 rpms, with slicks the car be launched right at the where boost begins to achieve max spool up. For example go watch the video posted between the NOS/TT C5s and listen carefully to their launch rpm. So consider this when examining what rpm you want your boost to build at.

An example of where having a benefit to building boost in the low-mid rpms (1800-4500rpms) is something like on my Duramax Diesel. It is beneficial to have the turbo spool in the lower-mid because that is ideal for towing. Corvettes are light and don't require a lot of power to get them moving at the lower rpm..and even the stock 346cid at a lower CR will burn the tires off if launched in 1st gear between 1800-2300 rpms (at least mine does).

Do you really want your max spool up to be at that rpm range??? Probably not..unless of course you have a trailer hitch on your Vette and need to tow the jet skis to and from the marina.

I have been averaging 19.5 gallons when driving around lately..and that is getting on it in 3rd and a little in 4th. I find 3rd gear to be the real go getter on the street...because once I am through it and shifting in 4th...there is no reason to be going over 100mph that much on the street....all that it does is increase my need to change out the rotors.

I provided this example because it applies to the spool up time based on your cid and turbo selection, AR as well. Remember that a 402cid has more exhaust energy then a 346cid..so if choosing a GT series Turbo go with a GT35, if choosing a non ball bearing turbo...go with 60-1 style turbo with a .8x AR in a T3. If you start talking T4 the AR is going to drop. An AR of .81 on a T3 is not the same dimension as a .81 AR on a T4...so you have to adjust accordingly.

Between the TTi kit and my PTK kit, there have been 6 different Turbos/housings on my car. So far I like a 60-1 or like wheel on my car. With a T3 flange a .81, with a T4..I think I have a .58 AR...dropping it from a .69 dropped the spool up rpm by 300rpms. The best part about all of this, is that there are options to customize turbos around the CFM output of your motor, spool, power, etc..