Overspooling smaller turbos?

[JantzenOKC]

Is it possible to overspool a turbo by not having enough backpressure? I have a V6 and am running two garret gt28 journal bearing turbos. The reason I ask is I just picked up a brand new factory V8 LS3 full exhaust(for a good deal) and thought I'd try it and see how quiet it Is. It's setup exactly like my factory exhaust was except 2.5" instead of 2.25" so hopefully it will be drone free. Might have to replace the hpipe with the magnaflow resonated xpipe to get it to sound good. If I like it I'd like to put electric cutouts in it and have a two way exhaust. I've been told dumping the exhaust too close to smaller turbos like these can overspool and damage the turbo. But have also been told that it wouldn't. I figured I'd get some good opinions in here.

I could either put the cutouts at that first bend in the exhaust about 16-24" from the turbos(not sure what that would sound like) or maybe at the rear right before the mufflers. I just want to be able to drive around drone free but then have good flow when I need it. Plus the trash can mufflers will add to the sleeper effect.

These are the turbos I'm running: http://www.atpturbo.com/mm5/merchant...egory_Code=TBN

Any opinions are appreciated.

[stevieturbo]

Really havent a clue what you're asking

Is it possible to damage a turbo from over spinning ? yes.

Will fitting cutouts cause this ? no.

Can poorly sized turbos for the application be overspun and be damaged ? yes.

[JantzenOKC]

Sorry I could have been a little clearer with my question just trying to give a little info of what I'm doing. My question is if the turbos are properly sized to the application and work well could there be any harm in installing cutouts too close to the turbo? If it's a stupid question then forgive me as I've never had a turbo car until now so not a lot of experience with them.

The only reason I want the cutouts is because I imagine the factory mufflers will choke off some power. So I want to be able to open it up at the track or when needed.

[Unreal]

Factory mufflers are great, and I seriously doubt they are hurting at your level. I run 100% OEM mufflers/axle back on my car making 1200rwhp, and friend runs the same on his car making 1460rwhp. If the only reason to do cutouts is to bypass the mufflers for power, I would seriously suggest spending money elsewhere.

[JantzenOKC]

Originally Posted by Unreal

Factory mufflers are great, and I seriously doubt they are hurting at your level. I run 100% OEM mufflers/axle back on my car making 1200rwhp, and friend runs the same on his car making 1460rwhp. If the only reason to do cutouts is to bypass the mufflers for power, I would seriously suggest spending money elsewhere.

I assumed all the camaro trash can mufflers would flow bad. But now that you said that I started googling muffler cutaways and I was surprised that the LS3 mufflers are straight through. So youre right they prob don't create any backpressure. Also might not be as quiet as I'm hoping, but I think a resonated x-pipe might help. Also found a cutaway of the my v6 mufflers, there is a lot going on in those!

Thanks man, appreciate the reply.

[stevieturbo]

Originally Posted by JantzenOKC

Sorry I could have been a little clearer with my question just trying to give a little info of what I'm doing. My question is if the turbos are properly sized to the application and work well could there be any harm in installing cutouts too close to the turbo? If it's a stupid question then forgive me as I've never had a turbo car until now so not a lot of experience with them.

The only reason I want the cutouts is because I imagine the factory mufflers will choke off some power. So I want to be able to open it up at the track or when needed.

How much power they might reduce, will obviously depend how much power you have in the first place.
IMO those small turbos will be a limiting factor before needing cutouts with almost any exhaust.

[SSE 4 2SS]

It's entirely possible to over spin a turbo or twins, ask me how I know since I have a trail of broken parts to prove it.

However, the back pressure reduction from opening your exhaust up a bit is minimal at best. Why not just put the LS3 exhaust on and forget about the cutouts... What size are your downpipes and are you going to change them to match the exhaust piping or just cross it over right at the connection.

[JantzenOKC]

Originally Posted by SSE 4 2SS

It's entirely possible to over spin a turbo or twins, ask me how I know since I have a trail of broken parts to prove it.

However, the back pressure reduction from opening your exhaust up a bit is minimal at best. Why not just put the LS3 exhaust on and forget about the cutouts... What size are your downpipes and are you going to change them to match the exhaust piping or just cross it over right at the connection.

I guess I just had it my head that even the stock ls3 mufflers would be restrictive but since they aren't I really would have no need for cutouts. Whether this will be the sound I'm looking for or not I don't know, but it was only a $80 investment so it's worth a try. My down pipes are 2.5" and hook right up to the factory exhaust. V6 exhaust is 2.5 in front of the hpipe and 2.25 everywhere behind. I'm still running the stock 2.25 between my xpipe and muffler delete so this might actually be an improvement.

[Stitch]

Turbos are most efficient with zero back-pressure. Any back-pressure creates resistance against the rotation of the turbine.

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