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Discussion Starter #1
whats the largest t4 based turbo that will fit on a on3 kit for a foxbody 8.2 deck. alternator will be moved to drivers side.
 

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Not sure if its the largest T4, but its up there. Im sure the downpipe and charge piping would not line up.

VS Racing
 

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B&G says in their kit a PT-78 is he largest that will fit. I only mention because I believe the On3 was a copy of that system. With that being said I believe their are companies that can build you a custom turbo of you need something bigger.
 

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what good is a "largest" turbo when you're limited by the downpipe size...
 

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I had a S480 on mine for a while
There is no reason with a good turbo like the PT 7675CEA I used, as long as the engine can take the power, a person couldn't get well into 5's with the ON3 plumbing. My first pass with the PT7675CEA was a 5.40 in a 3200 pound car with full exhaust.

I had an S480 82mm for a while with a 4 inch downpipe. It broke every month from the heat and weight, but it was already pretty well cooked from a year or two of 55 psi drive pressure.

I'd watch the turbo weight, based on how mine always cracked.
 

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Discussion Starter #9
tom i ave a 7675cea now and it made great power on my 306 was just thinking with the larger 363 larger victor jr heads i would benifit from a larger turbo. what was your combo for your 7675? this setup may have to do till i can afford a better hotside.
 

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My 72mm Magnum compressor housing nearly touches the alt with it pulled in as far as possible. Idk how you'd get something much bigger in there.
 

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I have a Precision T88, T-4 .96a/r on my on3 kit.
what size downpipe were you able fit with it? or are dumping through the fender?
 

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There is no reason with a good turbo like the PT 7675CEA I used, as long as the engine can take the power, a person couldn't get well into 5's with the ON3 plumbing. My first pass with the PT7675CEA was a 5.40 in a 3200 pound car with full exhaust.

I had an S480 82mm for a while with a 4 inch downpipe. It broke every month from the heat and weight, but it was already pretty well cooked from a year or two of 55 psi drive pressure.

I'd watch the turbo weight, based on how mine always cracked.
Yea the s480 weighs about 15 lbs more than most of the smaller offerings from on3. Its one heavy bitch.
 

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what size downpipe were you able fit with it? or are dumping through the fender?
I’m running the 3.5” one that comes in the 351 kit. It necks down to 3” at the turbo, so I cut that off and made it 3.5” the entire length. It would be tough to fit anything bigger in that location.
 

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^ smart move getting rid of that 3" section

with that said it sounds like the 76 is probably as big as one would want to go.
although other units "fit" who knows what's going on with the back pressure and EGTs which are two words that many forget or ignore. it goes back to guys in the road racing section posting "how big of a tire can i fit on a 9" wheel", or something along those lines, and then sooner or later someone jumps in says that they were able to get a 305 to fit... i'm sure you can get a 345 to fit... so what. fit and performance are two different terms.
 
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