Turbo Guru Required...

[omi]

I need to work out the best turbo for a specific application - I've already checked the Ray Hall calculator, but that only shows turbos he sells and I'm hoping to avoid £400+ for a ball-bearing custom GT if there's a £150 solution in the local scrapyard.

I'm converting my NA BMW to FI, with the cunning use of mirrors and magic... Before you call me nuts, it's perfectly reasonable and a good way to essentially double power while keeping the same great car and handling and without dropping another unsuited engine in there.

Engine is a BMW M42. 1796cc originally, slight overbore for pistons.
Going 8:1 compression with custom JE forged pistons.
Forged crank as standard.
Forged rods as standard.
Solid lifters off M3 S52 engine.
Cosworth/Mercedes intercooler.
Custom tubular manifold.
Megasquirt n Spark Extra ECU, with MAP, TPS, Knock and Wideband O2 sensors.
Custom Blue Flame exhaust.
Uprated fuel pump and 50lb injectors.

According to my calculations I'm looking at reliable boost of 14-17psi, which translates to 260+bhp.

Looking for the best turbo to handle that boost all the way to the ~7000rpm limit, with lowest boost threshold possible.

Might need my head examined too.

Thoughts please gentlefolks?

Omi

[stevieturbo]

Given the small engine, a Mitsubishi TD04 as fitted to most UK Imprezas would suffice, and spool pretty quick. At a push it will make 280bhp, although thats it.
The bigger TD05 has seen around 350bhp on plenty of cars ( in straight entry form, not the 90deg elbow it us usualy burdened with )

You should be able to buy these pretty cheap.

Even if it isnt enough, having that fitment opens the door to quite a few other possibilities at fairly sensible money.

And BTW, you havent a hope in hell of buying a real, new BB turbo for anywhere close to £400.

>> Edited by stevieturbo on Tuesday 31st January 18:07

[eliot]

omi said:

I've already checked the Ray Hall calculator, but that only shows turbos he sells

Was that the online version? - Click on the free downloadable PC based one that includes all the old skool turbo's. (not that you will easily find one in the uk though)
td04's are usally to be found on egay.

[stevieturbo]

TD05's will be pricier, as they are a well proven turbo for Subarus.

Or there is the IHI range, but again, these tend to be dearer, although are same fitment. single BB turbo.

TD04's are nearly throw away items for a lot of Subarus.

[stevieturbo]

TD05's will be pricier, as they are a well proven turbo for Subarus.

Or there is the IHI range, but again, these tend to be dearer, although are same fitment. single BB turbo.

TD04's are nearly throw away items for a lot of Subarus.