Tma twin viper kit nearly finished

[Andy@TmaTurbo.com]

Originally Posted by JuniorGTS

Dont you think you will run into problems running low boost with the 38mm Gates and those tiny back housings? Its 4.0ltrs you will be pushing through each of those tiny housings and gates..

I've ran low boost built up 4.2L v6 engines all day long on low boost with no problems on a single 38mm wastegate. Thats 6 cylinders feeding a single 38mm wastegate and not even a single boost creep.

With the way my wastegate is free flowing vented to atmosphere I have no doubt in my mind the 38mm can do the job.

Those back housings aren't exactly tiny Eaither. They are T4 .70 turbine a/r. These are much larger then the GT35/40R T3 housings.

I've also seen SVS and underground racing using 38mm wastegates on their setups vented back into the exhaust dump pipe. Worked fine for them.

[The Former PFR]

.70 is too small. I would go at least one size bigger.

[Andy@TmaTurbo.com]

Originally Posted by The Former PFR

.70 is too small. I would go at least one size bigger.

The intended purpose of this car is for road racing. Your mostly in the 2k-4k range around the corners. I feel the .70 turbine a/r is a good choice for all around power and good for the twisties. I don't feel in any way my turbine is a restriction since it uses a T4 footprint with 3" dual dumps And again SVS is using T3 turbos on their side mount kit so mine is huge in comparison to theirs.

But ya whats good about the kit I built is that the turbos can be swapped out for some PT67 .96 turbine a/r ball bearings. Should be good for 1400 hp. For those that want more of a street/strip/drag setup.

[davem_f1]

Originally Posted by Andy@TmaTurbo.com

Hey Dan. I had a few more questions. I just want to make sure I do it right. I was afraid of using oil restrictors b/c i've heard they starve journal bearing turbos oil and may damage the turbos. But I think I will be okay to use restrictors since the viper has a high flow oil pump.

Why do you have a check valve before the turbo? The turbo is always fed with high oil pressure on the feed side so i don't see why a check valve before turbo is needed. Since the oil is at 60 psi+ on the feed side why would it ever see back pressure?

Also why a check valve on the drain side. If the turbo is above the oil level no oil would enter back into the drain line.

I'll do it and get these parts but it has to make some sence to me

Im guessing you get the supply of oil right at the oil filter unit. I have to unplug the brass plug? Thats how mustangs are must making sure its the same for vipers.

Alright Dan thanks for your help

You do need a restriction and check valve on the feed side, easily done with a T into the oil pressure sending unit, and put the sending unit on the turbo side after the restriction, that way if you get a piece of crap in the restriction, you will see it on the stock gauge and save the turbos. This is how I run mine. I found with the shurflo pump you do need a vented oil pan (possibly because I run ball bearing turbos and the seal is not as good), but don't need an exit check valve if you dump back into the oil pan above the fill level, or into the valve covers. Mr Turbo has a very nice scavenge pump that he uses on his bike kits, it is very small and a lot cheaper than the shurflo. I've had very good luck with them, and I've used both types of pumps on my viper.

-Dave

[davem_f1]

Originally Posted by Andy@TmaTurbo.com

This kit was originally built for my dad. After completeting this kit i can see why other companies charge the prices they charge. Its a lot of work and a lot of labor. Took a tad bit longer then building turbo kits for mustangs.

But ya if I were to sell it I would sell it for around $9999 complete to tail pipes. Subtract $800 if you already got a cat back system. The other good thing is that you don't have to wait month's for it to get build and this kit is a true weekend bolt on intended for the DIY crowd.

My dad and I are going to run just 3.6 psi of boost on stock fuel stuff. My dad is starting to realize he can't afford to complete this project so we're stuck in low boost mode or we're going to sell off the kit.

If you pick up a bunch of Subaru STI side feed injectors, I can mod them to flow approx 80lb/hr. These will fit in the stock manifold, you do have to change the injector connectors. This would save you the cost of fuel rails and is a cheap way to run higher boost.

-Dave.