AlexLSx7

I have a pair of Precision 6766 turbos which have 3" outlets on the compressor housing. I have a badass custom dual inlet intercooler which I bought a while back but have just realised that the inlets on the intercooler are 2.5".

Is it going to severely restict the turbos going from 3" to 2.5"? The intercooler piping will be very short as well. Probably just a 90 degree bend from the turbo to a small bit of aluminium to another 90 to the intercooler.

It doesn't really look like there is much room to increase the size of the intercooler inlets either.

I'm looking at running 800-900rwhp.

Forcefed86

iTrader: (4)

It'll be fine.

AlexLSx7

Thanks mate, its actually going in an LS3 FD as well

stevieturbo

Enlarge the cooler to 3" then ?

Or just buy new covers that are 2.5" outlet ?

And whether anything restricts...depends at what level you might be at or aiming for. A pair of 6766's seems a tad on the large side for only 900hp
They should be good for near 1500hp, so absolutely no issue with a pair of 2.5" pipework.

AlexLSx7

Thanks for the reply.

I don't think there is really much room to get a 3" inlet fitted either side but I may take it to a welder I know as I will **** it up and see if he can do it for me. Hopefully won't cost to much

DBRODS

iTrader: (1)

You could put a pair of ported S covers on or just reduce the H covers from 3 to 2.5". It wont make a difference.

roastin240

iTrader: (13)

If I had the room, I would weld 3 inch inlets on the intercooler and run 3 inch plumbing, then 4 inch to the throttle body. But for simplicity you could just run a silicone reducer right off the compressor outlet and then 2.5 inch plumbing, or run 3 inch plumbing and reduce at the intercooler inlet. Either one of those will support 900 HP.

For reference I made 480whp and 532wtq on a shitty poor flowing v6 from the early 80s with a single 2.25 inch intercooler pipe at ~21psi

stevieturbo

3" is overkill for your needs.

As already said, if the visuals are important then buy a new pair of covers with a 2.5" outlet. They probably wont be that expensive.

How will you be exiting the turbo ? Straight ? silicone ? alloy bend ? other ?

The cast alloy bends tend to be thicker than tube, so a 2.5" ID bend wouldnt look so out of place welded to the 3" discharge, but would then lead you into your 2.5" OD better ?
Yes there would be a step inside...but not the end of the world.

Or just use a silicone reducer somewhere etc. Lots of options

And plenty have made 1000hp through a single 3" pipe, some more, some less. They've probably done it on 2.5" too, although I'd think that is pushing a single pipe a bit far.

So I wouldnt worry either way. Do whatever is easiest, looks best, fits best etc etc. But 2 x 2.5" pipes will cover anything you'll ever throw at it.

AlexLSx7

Visuals arent particularly important as it is all low mount, you wont see the intercooler piping at all.

I will probably be using a 3" silicone 90 degree bend into a small bit of ali pipe, then into a 3" - 2.5" reducer to the FMIC. If i cant get the 3" inlets on.

This is the intercooler. It has made 1200rwhp on the car it was made for which had GTX35R's with 2.5" covers.






I just want to make sure i get it right the first time as i have killed myself spending money on this car already and i still need to throw about £2k at it!

stevieturbo

Ahh right, it's Craigs old setup ?

You can buy 90deg silicone reducers too so you can stick it straight onto the turbo with no steps

http://www.ebay.co.uk/itm/Silicone-H...-DMPK7EEeVCrVw

Or run 3" to the cooler then just a straight silicone reducer at the cooler inlets.

Whatever is handiest really.

stevieturbo

And if you can weld, these can be good value for lots of alloy bends to cut/adapt to form the pipes

http://www.ebay.co.uk/itm/Universal-...gAAOSwA4dWM1F9

The clamps they supply are ***** so just throw them away, and the silicone not usually the best, but they can be used ok.

But if you are unsure of what bends you need, rather than buying lots of separate bends and pipe...these do work well.
I got one a few years ago from Toyosports on ebay, was even cheaper back then and it really was a bargain, was able to make all my turbo to IC pipework from the one kit and still bits leftover. Your pipe runs look to be a lot shorter than mine

AlexLSx7

Its only the intercooler from Craig's car, unfortunately he sold his turbo kit on or put it on another car .

Thanks for the links!

Yeah i can tig weld but not amazingly, i only just started when i started turboing this car. i might buy that pipework kit just to keep in case i want to make some more bits up though.

So the two reducers i would need for either side will be about £40 so i will speak to the welder and see if can add the 3" inlets on as i have loads of 90 bends in 3" already.

Thanks for all the info, much appreciated!