co2paintballer

I have an 87 Turbo, and im planning on getting a downpipe/midpipe and a couple of mufflers, maybe the N1's, anyway i definitely want to keep dual exhaust....so my question is, can i buy the mid/downpipe and mufflers and have a shop weld a Y pipe from midpipe to mufflers? I am very curious about the size of tubing, i wanted to go 3" all the way from turbo, but then would i want it to split into 2 3'' pipes or somewhat smaller? My friend told me something about having 3'' would make me lose a lot of backpressure but i think it would be fine. Please help me out, any help is appreciated, thanks in advance.
-James

co2paintballer

Would i benefit at all from 2.5" piping instead? Anyone?

rotary>piston

the loss of backpressure is what makes it faster. With that kind of piping (the 3") you'll need a new fuel pump at the bare minimum, and an FCD (fuel cut defender) to avoid detonation. You'll probably be pushing 11+ psi, and you're going to need to port the wastegate to avoid boost creep.
In other words, the piping is the least of your worries. But hey, if you set it up right you'll probably be able to beat FDs.

co2paintballer

Wow, sounds good, i knew i would need a fuel cut defender, but would i really need a new fuel pump? Since i do plan to make this car considerably fast in the future, is there some type of fuel pump i can buy that can be adjusted, so that it is sufficient for my new exhaust, but that i can step up once i get bigger turbo/ported etc? Basically i want something good so i wont have to upgrade again in like a year or so. Thanks for all the help!

dr0x

www.sportcarmotion.com has good prices on a walbro 255lph pump (if its not listed just email him). Dont cheap out on it, it is one of the most important parts on your car. You would never have to replace it with a bigger pump down the road either.

Your friend is thinking about NA cars when he says there would be too great of back pressure loss. Which is some what true. However, on a turbo car that rule is totally irrelevant. 3 inch pipe will work fine for you. When you are installing your new downpipe, I say take the time to pull off the wastegate cover and port it.

rotary>piston

my friend with only 2.5" piping starts running lean in 3rd gear, so a new fuel pump is a must. he's only running about 8-9psi.

Bigretardhead

actually, the most boost I've ever seen is 8. never went above that. so why would it run lean in third, with the boost not going any higher?

ponykiller

it would run lean because of the load and boost. Usually max boost is made in 3rd and 4th gear because of the increased load on the engine which is what really determines boost.

co2paintballer

Walbro 255lph high pressure intank fuel pump

Is this the one i want?

co2paintballer

I found one for $105 shipped, anyone know of a place that can beat that?

rotary>piston

As the rpm increases, more fuel is required. I was watching the meter, you were getting leaner and leaner as you went up.

mr_vaughn

iTrader: (1)

I had a 3" Racing Beat down pipe and Racing Beat Mufflers and a shitty 3" main CAT. and was only getting 4.5 #'s but noiw after chanig the CAT with a Racing Beat presilencer i am hitting 12/14 #'s now.
i have to now turn it down
here is my setup
Walbro Fuel Pump
Mariah Cold Air Box
K&N FIPK
Greddy Type S Blow off Valve
Catrol 20w-40
Center Force Dual Friction Clutch
Racing Beat Turbo Catback Exhaust system.
3mm Apex Seals
Street ported on exhust and intake ports
new engine wire harness
Braided Stainless steel oil cooler lines
Lightened Steel flywheel
Magnecor 8.5mm Sparkplug wires
NGK Platium Spark plugs
Silcone Vacume lines
Custom Turbo Inlet duct

mr_vaughn

iTrader: (1)

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Haltech , 1000cc injectors , greddy front mount intercooler and the radiator