External gates vs actuator

[5teve L]

When do you go for external gates rather that actuator ?
I'm looking at turbo's at the moment & with the log manifold I'm a bit restricted for what size turbo I can fit, I know a 28RS will fit so was going to go up to the 2871 which will still flow enough for 400hp if I need it, thing is I'm not sure if the actuator will be ok as I'm not clued up as to why people go external gate, is it after a certain boost pressure ?
It's either that or I'll have to look into getting a manifold made so I can fit a larger unit like Robbie & Mark run from the off = more time & expence :scratch:

I'm prob looking at 300 ATW once mapped up maybe a little more if the box will take it.

[Andrew Cooke]

I don't think I'd use a 2871, it's quite a mismatch in wheel sizes. Go 28RS (with a 0.86) with an internal gate, or something bigger and external.

The reality is that you'll smash your box to bits, so you may as well stay smaller.

[5teve L]

I don't think I'd use a 2871, it's quite a mismatch in wheel sizes. Go 28RS (with a 0.86) with an internal gate, or something bigger and external.

The reality is that you'll smash your box to bits, so you may as well stay smaller.
Thanks Andy, yes I know the box will be the weak point, I'm hoping to put a diff in & have it rebuilt, at the very least it needs a rebuild with a new diff ring instead of the circlip :crap:

I'll look into the RS with the larger housing, never thought about that option actually. It's either that or tubular manifold & bigger unit.

[Andrew Cooke]

Thanks Andy, yes I know the box will be the weak point, I'm hoping to put a diff in & have it rebuilt, at the very least it needs a rebuild with a new diff ring instead of the circlip :crap:

I'll look into the RS with the larger housing, never thought about that option actually. It's either that or tubular manifold & bigger unit.

Throwing money at the box doesn't necessarily make it stronger, the only one I broke had just had 1500 thrown at it, 10 miles it lasted.

I bought 2 GT boxes as spares, they'd both blown the main shaft out of the end of the box.

The 28RS was designed with the .86. Do you have the space for the correct compressor housing, or are you using the T3 one?

[5teve L]

Throwing money at the box doesn't necessarily make it stronger, the only one I broke had just had 1500 thrown at it, 10 miles it lasted.

I bought 2 GT boxes as spares, they'd both blown the main shaft out of the end of the box.

The 28RS was designed with the .86. Do you have the space for the correct compressor housing, or are you using the T3 one?


Sorry Andy, no idea till I mock it up on the car, plus I have no clue what you mean by the above statement:ashamed:

RE the gearbox, well only time will tell I suppose, plus the extra spool time from the larger turbine housing should help a bit I suppose.