Is there a real benefit in going twin turbo? I know it'll cost more... but how much would it actually cost since my single kit is gonna cost me like $7500? I was gonna go with a T76 GTS-H with an 80mm wheel and a air to air intercooler.

But if I went with twin T67s or something to that effect... wouldn't it just be more efficient?

This will be a street driven car... looking for as much power as possible. haha

625whp on pump is the goal and 900whp+ on C16

 

With the right heads/cam combo and as much displacement as possible (396+) you shouldn't have a problem getting 625+ on pump gas. I think most people are going to tell you to go with the single turbo, but yes, two smaller turbos would be more efficient. One thing you have to remember is that if that T76 doesn't spool up till 2500rpm then you could drive it on the street with little effect on your gas mileage and driveability.

 

It's a 385 right now. Lloyd did the heads/intake and Nick from VRE will be doing the cam. I am just shopping around right now for what could be the best thing for me.

If two turbos would be more efficient... :-) Twin T67s just sounds pretty to me. haha

 

Twin T67's might be too big to be efficient. Granted you could make alot more power, but spooling those turbos would be difficult for you motor. I can't really tell you for sure, as I am no expert. I think the main concern with twins as opposed to a single turbo is cost. You'll probably be very happy with the results of a T-76 GTS, so why spend more than you have to?

 

>because he can

jk But seriously are you saying that a big single will make more power than dual smaller ones? just like a 3" single exhaust flows more than dual 2 1/2" exhaust?

I personally like the idea of having twin turbos on my Silverado, but a big YSi on my Camaro.

 

I do agree with you though, if he has the money, go for it. It's just cool to say "My twin turbo Camaro...."

Edit: and no, 3" exhaust has 7.065sq. in. opening, dual 2.5" has 9.8125sq. in. opening.

 

I don't think that is correct. It's the same concept behind 4 smaller valves as opposed to 2 big ones. Now if you look at the efficiency in terms of hp per $.....the big single has it beat by a long shot.

 

It's because i'm saving for a nice power adder either way. If i'm going to do it, I want to do it the way I want to the first time. Nothing is written in stone... this is just something I am considering because it's possible. Besides... if I can make more power on pump gas then I want too. I want 625-650whp on 93 octane.

 

Twin turbo's will make the same power as a single if they run at the same compressor and turbine efficiency. There simply is no difference as long as selection is equivalent.

All of the drag racing classes only allow 1 power adder and twin turbo's is considered dual power adders. For this reason, all of the serious guys just use 1.

If you are reaching the limit of the T-76GTS, then it would be beneficial to install a larger T-88 or T-91. In this case, you may not be able to fit a large frame turbo. However, as INTMD8 showed us, you can hide a couple of small ones down low and keep all the accessories. But, with the T-76 proven to 1000 rwhp, I don't think you'll be reaching its limit.

The one place where the twins will have an advantage is lag. If you install twin turbo's that are the exact equivalent to a single, then the twins will spool quicker because of the much lower overall rotational inertia. It is easier to speed up 2 small wheels rather than 1 big one because of where the mass is in relation to the centerline of the shaft.

Mike

 

Well you have to look at it this way. The amount of air that each turbo flows can be made into a graph showing size in mm, and flow rate in cfm. Now that graph is going to curve upwards and eventually level off. Let's say you have one big turbo flowing 1000cfm at 6000rpm, and 2 smaller turbos that flow 500cfm at 6000rpm. My guess would be that if the big turbo was a T-76, the smaller turbos would be T-35's or less. I'll try to get some hard facts to back this up. What I'm basically try to say is that if you have the same power goal, twins should spool up quicker with the same resulting HP. If you have a goal for spool time, twins should give more total airflow.

Let me get back to you with some facts.

Chris, if you have the money to spend, then buy exactly what you want. If you're like me and will always be curious about having twin turbos then go ahead and try it out. The truth is you will most likely achieve your goal of 625rwhp without any problems either way. I think you would be happy with either setup, just one will come out alot cheaper than the other, just won't look as cool

 

But once I turn the boost up to like 18-22lbs... wouldn't the twins (assuming I didn't choose IDENTIAL Turbos in theory, but better ones) make more power?

I guess another way to put it is that I want the ultimate goal to trap in the 155-160mph area. haha I want the most badass F Body for the street. I will of course have drivetrain mods. The suspension mods will have to be done individually to try to keep things level. I want a good handling car but a car that won't grab traction til 3rd-4th gear really won't make me happy either.

 

I wouldn't worry about "boost" in terms of psi. What you need to worry about is cfm at rpm. In reality you want to flow as much air (cfm) with as little pressure as possible (psi) because excessive boost pressures just create more heat.

I saw your other thread and think that is a great idea. Find out what other people are running, when they start building boost, max hp, etc. Someone is bound to have the same setup you want.

 

You'll be pushing the limits of the T76 if you want 155-160mph (high boost levels ~22-24psi). You might as well go twins or a T88 then.

 

Yea because the car will probably be @ 3500lbs with me in it. I want to keep the car pretty much stock... inside and out. The only things that would be different are the performance pieces

So I figured I could shrink the T76 to to T60s or whatever... T67s just sounds badass (Just an example though) and be able to reach my goals.

I think Jose uses a PT88 and runs 139traps on pump and 153 on C16. That is right around where I want to be but a little faster on C16.

 

I could be wrong, but I think those were his customer's #'s.