f20b turbo build

[fstacrd]

Here is godspeeds website...http://gpopshop.com/products-page/al...g-turbo-stock/

[deevergote]

Where did you hear that internal wastegates are more reliable? That's not true at all. Quite the opposite, in fact. A quality external wastegate is always superior.

[91kid]

Im in the process of building a boosted B18 in my civic, and the GT2871 has been recomended a few times, BUT i have also been told that being the small size it will be pretty much pegged at 300-320hp and this is on a motor that only revs to 6800rpms, with the extra displacement and the fact that the f20b is more rev friendly I WOULD AVOID this small turbo as it will run out of breathe a ways before your redline and will not support 400hp

i would look into a gt3071 with your goals

copied from ATP's site

This turbo is great for small displacement engines up to 2.2L and has the ultimate spool up time compared to other units. This turbo has a flow capacity of about 400HP. The external packaging of this turbo is identical to that of the GT28RS and can be a nice stealthy upgrade to step up to 400HP of flow without much re-arrangement.

Turbine
-Wheel: 53.85mm w/ 76 trim
-Housing: .86 or .64 ar
-Maps

Compressor
-Wheel: 71mm w/ 56 trim
-Housing: .60 ar

[fstacrd]

I posted the other turbo on craigslist for what I bought it for so soon it will be gone and will be buying something else. thanks for letting me know this info and I will look into the turbo that you recommended.

[fstacrd]

Ok.. I did some more pricing today and I need advice.. is 1500 a good price for a shop boring 1mm over, 3 angle valve job, doing all the valve train, and micropolish the crank?

also need someone to tell me a good size turbo to go with that will be within 450 bucks just for the turbo.. thanks

[Joey GT-R]

$1500 seems fair for you machine work if it includes a re-honing of the cylinders with the bore.

For $450 all you're going to find is that chinese knockoff "Garrett" you're trying to sell. The best "entry level" turbo IMHO that will meet your needs can be found here, but you'll need to save up a bit more.

[deevergote]

$450 will likely get you a decently sized used turbo. Of course, used parts come with their own risks. You could end up spending a chunk of cash rebuilding it right off the bat.

[Joey GT-R]

Unless it's a turbo off a drag car that ran for a couple passes or was a dyno tune test mule I'd leave used turbos alone. Even if he found a used Garrett that had some shaftplay/leaking seals/etc, the rebuild kit and labor would run him the price of the PTE I suggested, but that's my estimate.

[fstacrd]

the precision turbo sounds nice.. and the price did include hone.. where should I run the wastegate dump tube to?

[deevergote]

Into the exhaust piping is most common.

[fstacrd]

Into the exhaust piping is most common.

so if I am doing the h22 t3/t4 cast iron manifold, then I run the top mount wastegate dump tube to the downpipe?

[Joey GT-R]

Either that or have it vent out to the air. Some people cut holes in their hood so the outlet can sit flush against the surface; it can look nice if done right.

[Grumpys93]

i personally like having my WG dumped atomosphericly, since you don't have to worry about any kind of backpressure. Plus when the WG opens with a screamer pipe sounds pretty sick. You can run it up the hood or along your downpipe and out the bottom of the car or to the side of the front bumper.

as for turbo on my setup i plan to run the precision sc6262. Good size turbo and decently priced. You can find them for under a grand if your not looking for ball bearing

[fstacrd]

my thread kept getting deleted in the swap thread so i'll post it with my f20b turbo build.. to find out if you got the jdm f20b manual straight from the shipper, see if you have the manual flywheel on the motor as I did, which I luckily had one ..

[toycar]

Internal WG's do work better for the typical enthusiast.


Most guys don't setup an external WG to function correctly. Shit, most aftermarket manifolds just have the gate activated off of 1 runner. All the WG does is bleed off the pressure from the exhaust housing to slow down the compressor speed.



So, when the gate opens it effects flow on the runner that is now basically operating with a giant leak. That turbulence from the individual runner causes restricted flow at the collector and this is why internal gates operate the way they do. Running a y pipe for your WG to route into your DP is a good idea and helps with this flow issue, but does not solve it entirely. When flow is effected on 1 runner, it effects flow at the collector. When you dump to the atmosphere, you have nothing really to help maintain flow, its just wide open, and that drastically effects flow on the closest cylinder.


A quality external gate will releive pressure in the exhaust housing, and not effect flow in the runners between the port and the collector. How does this happen? Well, a quality external gate exits after the collector but before the turbo flange and MOST manifolds aren't designed for that. Few are. But as an example, look at the generic log manifold. External gate is directly on top of 1 cylinder so when the gate opens it effects flow in the plenum(log) of the manifold.


So, unless you are going balls out with a really nice manifold, you may as well run an internal gate. They ARE designed to be reliable. Most cars that have a turbo, have an internal WG. Those WG's see 100k miles usually w/out any problems. When setup correctly, an external gate works best. Setting one up correctly though, most people don't bother with that which then makes an internal gate better.