My question is this i have been for the past few months buying parts for a twin turbo set up i have a 350 Tpi forged crank and pistons, 8.3 compression, chromemoly pushrods, gasket matched heads, roller rockers, boosted application cam with matched lifters and heads. I have the crap ssautochrome T70 turbos just for mock up right now. a twin turbo intercooler, all the piping, RFL blow off valve, msd ignition, 50mm wastegates, custom exhaust manifolds, everything i need except the oil line fittings. Here is my question i have been looking at times for twin turbo fbody's and they are not as fast as i thought, should i sell this whole kit i got right now and supercharge it? or should i keep going and see where it goes. Need some inoput on this but please dont jump on my case about ssautochrome i know i know.

 

i think that most of the turbo charged F bodys are actually held back by the car not the engine... it takes a pretty good chunk of change to make these cars handle 600-700 HP day in and day out and get that power to the street... and BTW it would be the same if not slower with a supercharger do to the parasitic losses of spinning a blower

 

thats a good point i didnt think about that, im making the car handle also with roll cage and unibody ties, rear suspention upgrade, so i know that it should take around 600-700 hp i just dont know what way to go.

 

You can go just as fast in a single turbo setup as you can in a twin setup if it is built right. What it comes down to is what your willing to spend and what you want. The twin kit has more lines to run and double the expenses (turbo's, wastegates,more piping etc), but usually a twin setup will spool sooner than a single setup that makes same peak HP (let's say a twin T70 setup makes a peak 650hp, it will usually come into boost sooner than lets say a single GT45 etc, this also dpeneds on the turbine housing/wheel size, flange/port size, and how much heat you hold in the piping). The supercharger comment is true but a properly built blower setup won't see the power loss that people think due to parasitic loss. Plus depends on the blower you use (the step ratio's are different depending on brand, model etc). So what it comes down to again is, what do you want? If you already have the stuff for the twin turbo kit go for it. And like the guy above said, alot of the times depend on the car. If your running a twin turbo LS1 @15psi with stock suspension and street tires your not going to have very good times lol. I'm building a Twin setup on my 69' not because I want more power (I would go with a single GT45 but decided on twin H1C's), but because I can use an off-the shelf 3.5in dual exhaust system with race-pro mufflers and x-pipe with cutouts from Pypes. Saves a TON of time and money from fabbing my own setup and will sound and work great.

On a side note, 99% of the guys on here and other boards that talk crap about the XS-Power turbo's have never used one. There was a thread awhile back about a glued together compressor housing and it was a hoax, the housing wasn't like that from the factory, the guy bought it used, dropped the turbo and cracked it. He tried fixing it with epoxy and the result was the pictures and the stuff everyone talks about. If you check out www.turbomustangs.com, there are more than a few guys who have put these to the test just for the hell of it and haven't had a problem (a few guys have had them well over a year, one actually drove it for a year and a half, sold it, and the guy who has it now still hasn't had a problem). The big things with those turbo's is sometime you will get one with an oiling issue (that one is rare). The common problem (if there is one), is the balancing. A couple guys here in town and others that do rebuilds say the ones that come in are usually out of balance. If you wanted to be safe you could take the ones you have down and have them balanced at reputable shop and you'll probably be safe. I have a friend on the fuelslut board who bought one for his pOS escort project (it's a joke build lol) and he's a professional diesl mechanic. He took it apart at work and thinks the quality of parts is as good if not better than the garrett's and Holset's he deals with on a daily basis. He hasn't put his on yet but alot of guys on the mustang board and some of the honda boards have and actually have success so don't let the hype always fool you. Now if you have the money for a better turbo with a warranty and customer service backup GO FOR IT, but if your on a budget and not building a super build, these "can" work

 

twin t70's is good for 1000+hp, 600-700 each. use smaller turbos or a single mpt70.

 

I agree with RamairZ. Keep the turbos and use them! If they were manufactured within the last year, they should be balanced. The difference between the balancing from the SSAC and Garretts is that Garrett balances the wheels individually (neutrally balanced) and the SSAC (which should be Chinese Brand because you can buy them wholesale yourself) are balanced as a unit, in other words, you can't remove the comp wheel on the CB turbo and put it in another turbo without having it re-balanced. The other difference is the oil passages in the Garretts have a patented design that creates better flow (discussed before here at TGO by JYTurbo, IIRC).

Also, RamairZ is right about most people who knock these turbos have no experience with them. JYTurbo does, read some of his posts, Daves12secV6 does, read some of his posts - you will get two different opinions.

 

It looks like you have invest a lot of time and money on the twin set-up already it would be a shame to try and sell it and get a new SC.....

 

Thanks first firebird! Ya the T70's (depending on the size) can support 600-700 each as stated above, your's are probably around the 600 mark. Since you could still use the T70's but I would suggest running some smaller ones as well, the T70's from XS-power/SSAC/Chine love the 10-15psi marks. Much below that and they are near there surge area which is not good. You would most likely be running 4-6psi a piece which might put these into surge depending on your motor build. I would probably go with twin 50trim turbo's in your app if I was staying twins. Even a smaller 60mm would be good

 

thanks guys for all the input im going to look more into the ssautochrome stories... i m going to just twin turbo it see where it goes and if the numbers arent where id like them to be ill just use a little spray lol.....anyway thanks for all the help and when the motor is fully built and the turbos are on ill post some pics......some of the other stuff that i have bought is a serpintine belt conversion, edelbrock torque arm, hotchkis rear suspention kit, fbody motor sports front end rebuild kit, i have a firebird wing, stock body kit, proform light weight valve covers, 8pt roll cage, unibody ties, rci fuel cell, shaved gas door, still dont know tire size or color its just primer right now.....any input on tires or color drop some ideas....thanks again