F/I engine build help....

[B7 Quattro Man]

I have 90% of the needed gaskets to fully rebuild my 3.2, I had the walls finish honed, the heads decked about a year and a half ago. If I take the block and heads back in and everything specs out, would it be ok to use the stock pistons when wanting to run a turbo?

I have, rod, main, thrust bearings, valve stem seals, 3.2 head gaskets, full upper and lower 3.2 gasket sets sct. I will buy all the still needed parts when I figure out what they are, soon hopefully, and buy sensors as needed.

TIA

 

[twr]

How much boost do you plan on running? I would think 9psi or less would be safe with a turbo, you might be able to push a few more psi with charge cooling.

 

[B7 Quattro Man]

When I left the SHO game a little over a year ago, there wasnt too many FI SHOs, maybe 15 combined Turbo/Supercharged, and about the same with HC engines. Just from looking on the forum for 2 days, the number has increased dramatically. So, I do not know how much I want to run.


Are the pistons my limiting factors? I take it the tranny is still the big one? or has the T-5 come to save us? I plan on doing everything new, gaskets, bearings, seals, but dont plan on doing valve jobs, or anything like that.

You have seen what I have, I plan on cleaning everything, replacing every seal, gasket, bearing, adding sensors when needed. If I can get buy with stock pistons, I will. I plan on doing BBB's, researching gasket matching and port and polishing. But if i remember correctly, most said, gasket matching, EH runners, and so on are over looked when you are using a big turbo, yeah it will help, but not a bunch.

400hp would be nice, crank. 350-400 wheel hp. I would prob do an undetermined turbo, intercooler with custom piping.

 

[Jarrod]

A T-5? I'm assuming you're planning on throwing this in a RWD vehicle if you're planning on a T-5...

 

[B7 Quattro Man]

See, I still have some research to do, I just read one post, and I guess I skimmed over the RWD part. That makes sense.

No, sticking with the SHO body, just got confused for a sec.

 

[twr]

Right around 300 foot pounds of torque at the wheels is where 3rd gear starts to break. Not a question of if, but when.

Edit: It's torque at the wheels, not crank, my bad.

 

[somedude_001]

http://www.shoforum.com/showthread.php?t=62625

I am running 10psi on a engine with 219K on it, all I did was replace the rod and crank bearings (rod bearings were worn beyond belief) and I have BBB's and extrude hone intake. I also gasket matched the heads to the intake. based on what other people are seeing i'm right at 400whp on my ATX.

 

[B7 Quattro Man]

I guess my main question isnt the transmission, its if I can and should use the stock pistons?

I dont want to build a "refreshed" engine with stock internals and have it blow a year later right? I have a totally stripped block, honed cylinder walls and new caps. Looks like first step is to take block, heads, crank and pistons to the shop and see if everything is still in spec.

Would you guys recommend balancing the pistons? crank?

could you guys give me a little more info on gasket matching....

 

[CerberuS]

dont throw away your money on pistons. spare that money on useful mods instead.

 

[whiteman_01]

http://www.shoforum.com/showthread.php?t=62625

I am running 10psi on a engine with 219K on it, all I did was replace the rod and crank bearings (rod bearings were worn beyond belief) and I have BBB's and extrude hone intake. I also gasket matched the heads to the intake. based on what other people are seeing i'm right at 400whp on my ATX.

Hey, do you have a video of your car on streetfire? If so your car rocks. What turbo are you using?

 

[yamahaSHO]

Right around 300 foot pounds of torque at the crank is where 3rd gear starts to break. Not a question of if, but when.

I thought it was about 300ft-lbs at the wheels is what was in 3rd gear breaking territory.

 

[sho_sc]

dont throw away your money on pistons. spare that money on useful mods instead.

Whoa! I disagree. Just one lean condition while running more than 9-10 psi of boost, a ring landing will break on the stock pistons ... keep the boost in the 8-9 psi range and a 'good' tune, then it "maybe" o.k.

 

[yamahaSHO]

Hehe... I'm glad I have water injection, I've gone lean a few times because the SS MAF placement sucks. My pistons were fine and they're sitting in a box waiting to be given to Pat just in case he breaks some ring lands on the street SHO.

 

[B7 Quattro Man]

So its sounds like you guys recommend getting low comp pistons. I prob will go this route, just sucks because I am getting antsy. I wanted you all to say that I will be fine with stock pistons so I could start my build now, but looks like I will have to wait a while until I can afford pistons, wrist pins, and balancing.

Thanks all for your help. I am sure I will be on here shortly with another question that will stump me.

 

[Jarrod]

You don't have to go with low compression pistons if you're running a mild amount of boost...

 

[Geek SHO]

I thought it was about 300ft-lbs at the wheels is what was in 3rd gear breaking territory.

That would be my guess. If it was at the crank, everyone running the Zex kit would be mowing down transmissions. With a Y-Pipe, those cars are making somewhere around 315 at the crank.

 

[twr]

I thought it was about 300ft-lbs at the wheels is what was in 3rd gear breaking territory.

Yeah, your right. It is 300 at the wheels.... don't know what I was thinking