Ive got a LY6 with ls3 intake and 4l80e tranny.. I've done some research on turbo setups and just can't make up my mind so I need some help. I love the idea having them spool around 2500-3000 rpms so Ive been thinking twins but how small of twins could I run to get around 600hp? I also like the idea of twins because I could save a little money on my stall instead of blowing 800 bucks on a high stall converter? Im set on around 600 bc I don't want to stress the motor too much.. Plus I when I have the money to strengthen the engine I will upgrade the turbos. Or should I just go with a single 76mm? TIA

 

600 is a laughable goal for an LY6. If money is your worry, grab whatever is cheapest.

 

Couldn't agree more. My 6.2 cam only with a carb made 480/470 to the tire. A single would easily make well over 600.

 

since your ly6 is a V engine i would go with a twin setup because it will be cheaper and probably fit a lot easier under the hood. While it would seem like twins would be twice as expensive as a single, there would be a lot of money spent on piping the exhaust around and it would probably be a similar price

 

$70 worth of crossover piping isn't the same price as another turbo, extra oil feed and drain setup, another downpipe, and an extra turbo flange and another wastegate. Not even close.

You can get enough 2 1/4" mandrel bent piping to go from one side to the other for pretty cheap. I'm not sure where you're thinking thats going to offset the price of twins?

Btw, this is a stock LY6 with a cam and a pair of $320 On3 turbochargers.

The car has since made over 1000whp through a TH400 on the same setup.

600 HP could be done with a sub-$500 single turbo on that engine.

 

I realize I could easily make over 600hp with the motor… Thats why I asked what the smallest turbo setup I could run to reach that because I don't have the money to go into the motor at this point and don't want to stress it too much until I have the internals built..

 

Joe Nova wow that is impressive on stock internals! Could I run stock injectors? Im gonna throw the ls9 cam in it.. May not be the best but for 100 bucks Ill take it

 

Stock injectors? Cmon

 

How about a set of 58mm turbo's? They would be at full tilt at a very low rpm...may even do better than a supercharger...all at a very low boost psi, and the units are real small and will package nice. Any if you want more at a later date, the same units will deliver. I've been thinking about this myself...smaller turbos, tighter converter and better street performance.

Read the description on this kit using 58mm turbos:

http://uppturbo.com/parts/upp-05-06-gto-twin-turbo-kit/

 

I'm really not sure what you're worried about with the motor? As others have said, 600hp is pretty easy for a SBE LY6. But you said your set on that HP so lets roll with that.
You're main concern sees to be cost. So you need to ask yourself where youre going to end up with this car. What are you using it for? Im just going to assume this is not a dedicated track car and will be used primarily on the street with the occasional trip to the track.
With that in mind, youre realistically only going to be able to use around 700-800hp on the street unless you have some real seat time behind the wheel of a turbo V8 already or you spend coin on more advanced boost control (and traction control) and you learn how to set it up properly. Even then, more than 800hp on the street is pretty crazy unless you're into roll racing and you're seriously into the whole street racing scene and youre super competitive.
That all being said, the cheapest route for 600hp is a single chinese turbo set up. It will be cheap and make that power no problem. That motor will make over 1000hp no problem on a single. The only reasons i would go with twins are:
1. you just really want twins - thats fine but it will cost you more money and there is a slightly greater chance for problems simply because there are more moving parts.
2. The engine bay youre putting this motor in is very restrictive and you just don't have the room for a crossover for some reason. I would find this very hard to believe but I have seen one or two instances where a front or rear crossover just wasn't feasible.
3. you want to make over 1000hp. This isn't the case so...yea.
4. you find a twin set up for super cheap. Like less than the cost of a single set up.

Fast forward a year or two from completion of this build. You want more HP, right. Unless you want more than 1000hp (on your street car) upgrading your single set up will get you there with out much issue. And at the end of the day you've spent less money than a twin set up and made the same HP. Since you spent less money up front you might be able to upgrade everything for more HP sooner.

EDIT: Oh and you will not be able to use your stock injectors or valve springs FYI. The smallest turbo isn't necessarily the best either. You want it to light off quickly but you don't want too much back pressure either. And if you're expecting to make more hp down the road, if you size the turbo to make 800hp and light off quickly, you can dial it back to 600hp until you can forge the motor (which isn't really necessary at 800hp IMO) and still have solid performance.

 

I'm in about the same boat, OP. With an LS9 cam in a LY6 you should be well over 400BHP NA. All you need if set up right is about 7-8psi of efficient air to make 600BHP.

You could get by with a 76, but an 80 in a larger comp. housing would make more sense compressor wise. If you spoil a typical 76 too fast they don't like it. Most 76's are more of a higher pressure ratio turbo where the new 80mm+ in large housings flow copious amounts of air, efficiently, in lower pressure ratios.

For twins a pair of twin 66 or 67's would be pretty well matched.

 

600 easy peasy goal!

Good luck

-CE

 

Thanks for all the info! SenorThumpy yes its going to be just a weekend street car with the occasional track run for about a year or two.. I was also thinking the comp cams trunion upgrade.. thoughts? With twin 66 or 67s wouldn't they max out too quickly? Also what injectors would you guys recommend?

 

Jenna above your post has twin 67's on a 6.0. 800RWHP @ 14psi. I think he has stock heads... He can answer that aspect.

Twin 67's will generally do about 1200HP+ on the right engine. A cammed 6.0 is that engine.

If you only want "600" BHP, then 60's would work but most run 80's.

 

Yes twin 67s here on 14psi did 800rw (first dyno after 3yr build wasn't on kill)
I also do have a sbe and stock 317 heads

Twin anything can make huge power, mine isn't a good example this was the "get going" tune up.

FYI I added a few psi and the car went from a 10.1 to a 9.1 so these things are just getting happy! The sky is the limit with twins, but sadly I don't have the motor to support much more.
Rods n Pistons are needed!!

-Chris

 

This is what I was thinking for my build also. Twin 58 mm turbo's should do the job to get to the 600rwhp goal?

Would a pair of 54mm result in spooling much sooner than the 58mm? or is it a minimal difference...something like this
http://realstreetperformance.com/Tur...bocharger.html

 

it would probably be a similar price

 

I started out with twin turbonetics 61-65's on my L92 and it made 600 on 9#'s through a 4l80 and unlocked converter. I now have a bw S-480, but I'm thinking about going back a twin setup. It's a lot easier to package and it spooled very quickly.

I see you're in Macon, where about? I grew up there.

 

408GT, was the difference very noticeable between the big single and the small twins? Would you go back to the same size twins or bigger/smaller? Thanks!

 

Don't make the mistake of thinking smaller is better in this regard.

It is entirely dependent on how much flow you can have at what pressure ratio at what RPM.

Here's the thing, on a stock 6.0, yeah a set of twin 57/58mm comps would do fine if say limited to 5,500RPM. But throw in a bigger cam & rev to 6500 & those turbos could start blowing hot air at 80lb/min. That doesn't leave a lot of headroom for growth later, but it's up to the end user.