Shownomercy

iTrader: (1)

Crossover is currently 3 inch, and wanna neck it down a foot before turbo to 2/2.5 stuff.

76gts T4 turbo, undivided flange

Poor choice?

svslow

The 3" would be the poor choice here.

Shownomercy

iTrader: (1)

Its already there, seems to work just fine.

svslow

Got any pics?

Shownomercy

iTrader: (1)

svslow

Where on that are you wanting to make it smaller?

Shownomercy

iTrader: (1)

The single large section on right side. Would chop it, transition down, then run a 2.5/2 Vband to work up front to turbo

JoeNova

If it was fine, you wouldn't be wanting to reduce it.

Shownomercy

iTrader: (1)

Long story short, caught a manhole cover with hotside and it bent/crimped a lot of the pipe after that vband. So redoing that part and figured 2.5/2 is easier to work with and route.

rpturbo

iTrader: (47)

I wouldn't go to 2, maybe 2 1/4, but then again, I wouldn't do 3. I think either way, it all works, but I would think it will spool quicker with 2 1/4 -2 1/2. It's about velocity, just like a carb, bigger isn't always better, but that doesn't mean it wont work.

Depending on how long it's been together, and if you have any data logs, I would love to see some data once you change it.

chiaj144

iTrader: (4)

Not sure I understand what you're wanting to do. What size of pipe do you have off the manifolds? I went 2" off manifolds to 14" of 3" and I start to see positive pressure at 1800 rpm.

RealQuick

iTrader: (14)

Sounds like he is redoing the 3" pipe that connects to the pipe in the pic. The pipe in the pic is the crossover where two 2.5" pipes merge into a single 3" pipe. From there, the 3" pipe on the crossover connects to a 3" up pipe with the T4 flange.

Since he is redoing the up pipe, I think he just wants to know if there is a better size to reduce down to before the T4 flange.

IMO, if it spools fast enough as is, then leave it. If it take a little time to spool up, reduc it down to 2.5". I would leave it at 3" personally, but I'd be interested in the results.

Jon