Running a HUGE turbo-concerns about weight?

[TR Custom Parts]

Got a customer who has a 42-76 ball bearing air cooled turbo who wants to use it with our 4 bolt headers. He is concerned about the thickness of the flanges on the headers as he has 14 bolt heads and has to trim the flanges for clearance to the extra bolts. Says the turbo weighs about 40 lbs and the headers might not be strong enough to support the turbo. SHOULD he be concerned about this? Flanges on his set of headers is about 3/8" thick.

When running this big of a turbo is there anything special that needs to be done to support the weight?

 

[its2qik]

Got a customer who has a 42-76 ball bearing air cooled turbo who wants to use it with our 4 bolt headers. He is concerned about the thickness of the flanges on the headers as he has 14 bolt heads and has to trim the flanges for clearance to the extra bolts. Says the turbo weighs about 40 lbs and the headers might not be strong enough to support the turbo. SHOULD he be concerned about this? Flanges on his set of headers is about 3/8" thick.

When running this big of a turbo is there anything special that needs to be done to support the weight?

I wouldn't run that turbo without it being supported somehow. Eventually it will crack the headers like that.

 

[Squid4life]

I forget how much a regular turbo weighs in comparison, but if he/you don't trust the single reinforcement rod on there, you can always weld something a little more on there from the forward-most flange are to the turbo mount to help with the weight. He may need to improvise a little whether on the headers themselves or some engineering bracketry to make him feel better. I will have to dig up the 4 bolt S2 headers I have in the garage to see how the reinforcement is on those. It is pretty substantial, but can't picture it in my head right now...

 

[Squid4life]

Not a 3.8, but I like this bracket. Might be able to do something like this.

 

[TR Custom Parts]

Not really sure if thicker flanges would even help this situation then??? Since all that weight is hanging off the front of the header he is going to need to fab up something then. Obviously he probably can't even use the stock "question mark" stock turbo bracket right???

 

[bison]

Got a customer who has a 42-76 ball bearing air cooled turbo who wants to use it with our 4 bolt headers. He is concerned about the thickness of the flanges on the headers as he has 14 bolt heads and has to trim the flanges for clearance to the extra bolts. Says the turbo weighs about 40 lbs and the headers might not be strong enough to support the turbo. SHOULD he be concerned about this? Flanges on his set of headers is about 3/8" thick.

When running this big of a turbo is there anything special that needs to be done to support the weight?

There are hundreds of guys out there still running the stock engine mounts that have removed the factory lead donut/elbow assembly and basically have the exhaust post turbo working against the header as the engine torques over under power. GM and all manufacturers used those for that reason. They knew the engine was going to move and needed an area that will allow some movement. The amount of movement in the stock mounts is extreme when viewed on a chassis dyno. If they arent cracking headers then a 40 lb turbo isnt going to do ****. The bracket like the one in the pic just adds more resistance against the type of torquing i explained. I doubt this customer is still running a stock set of mounts and most likely has an engine plate in between the frame and engine to hold everything in place.

 

[Blazer406]

IMHO the large weight way out is a pretty good moment load...... and you combine that with hundreds of trips up to 1500+ degrees in the header pipes..... it is a big load no doubt.... the dynamics kick in when the engine torques over.... that big turbo wants to keep going in the direction it was thrust or accelerated from the engine movement. The header has to take that load..... and stop that heavy turbo and bring it back the other direction.

IMHO the big turbos do increase the stress on the header considerably.....

 

[Alky V6]

Use a tripod support with a swivel link to allow for expansion and movement. If positioned correctly the tripod could be over or under the turbo. A solid mounting, such as suggested in the pic that was posted, does little to allow for expansion and movement. Easy to fab, but is not the best solution.

 

[DR BOOST]

more than likely, the header will have to be reworked so that the turbo will clear the hood and the water pump nipple removed.

support bracing is a must.