I know there are a million of these "what turbos?" posts but I need a little help in the right direction. I am building a twin turbo setup and need to pick a set of turbos.

This is going in a 4,000lb Jaguar XJ6 with a 4L80E transmission and an independent rear suspension. I can only run and 8.5" wide rim and the IRS is not ideal with a high torque setup, so I know traction will be an issue. The rear end is a Dana 44 2.88 and will not break... however I have been considering moving up to a 3.08 or a 3.31. The 4L80E has a shallower 1st gear than the 4L60E (2.46 vs 3.04, I think) so 1st gear could be a dog if I don't do this right.

The car is heavy, the trans is big and and traction is going to be less than great. I want something that will be able to pick it up from a stop and still pin you back from a roll. The car will be a weekend driver. I will sacrafice a little performance for some reliability. I have heard the stock 4L80E should not be reved over 6000-6200k RPMs so that will be a limiting factor.

Here is my engine so far:
Aluminum 346 w/foged rods and pistons at 8.5:1 CR
317 heads w/polished chambers, 918 springs and hardened pushrods
Z06 intake manifold
Stock 98-99 F-body cam
Cadillac CTS-V cast iron manifolds flipped forward
2-bar MAP sensor
No fuel system yet, but plan on upgrading to billet rails and bigger injectors
All piping will be custom fabricated

I don't have tons of room up front, so I would prefer a physically smaller turbo. I will more than likely run an A2W intercooler setup and no meth. I would also strongly prefer water cooled turbos. I am thinking something with a T3 exhaust side might be good and probably internally gated. I am looking for between 550 and 700hp to the rear wheels... or whatever it takes to make this car really fun to drive.

Any suggestions? Not trying to break the bank here, so ball bearing are probably out!! I have been waiting for 2 years to buy these things and finally have the engine done and the cash in hand.

Thanks, -Dave

 

Here's my opinion,

For twins that are small in actual size ( and also cheap)
I like Garrets. I'm sure there are a lot of good brands but for the price of a new turbo around 650 to 700 (Ive seen these turbo that Im telling you on ebay for 590 shipped) Go with:
A t3/t04e hybird is a great setup

Turbine: t3 .63 a/r stage 3 wheel external wastegate with a 4 bolt discharge this housing is not very big.

Compressor: T04E (the E is very important) .60 or .50 a/r
and 60 trim wheel.

 

Cool, are there any twin kits that come with T3 turbine housings? Is anybody running twin T3 exhaust side setups?

Looking at the maps is good and all, but I would like to back it up with something that someone already tried.

 

Well,

I am in the process of a twin rear mount with two of the turbos exept with an .48 a/r turbine (because of the rear mount). I have tested the combo in a single verson on my cousins 2.8 vr6 jetta. It was rear mounted and full boosted in first gear by 3k rpm (7 psi). In a cruise mode 4 gear lugin around at say 35 mph it takes about 1 sec for boost to start and by 4 or 5 seconds its full boost. the math is not perfect for double the engine double the turbo but I think it will perty close. I will soon find out. I would love to show the pics but can not seem to figure out how to post. If you call an actual Garrett distributor from garretts web site the are great help. I questioned the performance of the t3 also. I thought it was old technology..........they say no way the t3/t04e is among the top performer for the money and a very efficient turbo all money aside. I too would like to see some post from others runnin t3 hybrids

 

I looked at the maps and from a compressor standpoint, the 54mm looks the best. I will probably buy through Forced Inductions so I am going to give them a call to get their opinion, however I would like to see if anyone else is running T04E compressors with their 346 LS1 twin setup.