Turbo Spec?

[polred]

Hullo peeps,wee question for people in the know.I am currently going down the F/i route on my 1990 325i.

The turbo i am using i have had for a few years,its a Roto-Master which was originally used by Janspeed on there RRC single turbo conversions. This turbo is huge,AR 60 in and AR 69 on the exhaust,looks like something you would find on a lorry/boat! No water cooling either.

I am still at the stage i could change to a smaller turbo if this one is to big?

Saying that i dont mind a bit of lag,but not having to wait till 4k to turn on the Butt Meter,lol. Standard compression on an engine out of a 91 325i also. Thanks in advance Paul..

[toby]

I don't know the answer to your question but people are often referred to this book by those knowledgeable about such things

Maximum Boost: Designing, Testing and Installing Turbocharger Systems: Designing, Testing & Installing Turbocharger Systems (Engineering and Performance) [Paperback]
Corky Bell (Author)

[ross2009]

that sounds like some thing for up to and over 500 bhp to me that is rather big
thats bigger than mine

your on comp on that engine will be 8.8-1 also

mines on full boost at approx 3900 rpm
so some thing that big will more than likely come on boost higher up
what sort of power level you looking at ?

[polred]

Thanks for the replys,I had one of these turbos on a LHD Range Rover Classic 3.9 a few years ago. The Zytec ecu wasnt pulsing the injectors,so i was running the standard ecu at 4 psi. It certainly gave the Rangey some get up and go! Had actuator wound right off iirc.
What size of wastegate would i need? As the Janspeed one i have has a tiny hole around 30mm at a guess.
Power level 250+ for now,where i live we have only 95 ron at the pumps I havent touched Internals yet(m50 engine getting that treatment),done the oil return into sump,turbo is on,just waiting on adapter for oil switch/t-feed,and still to plum in cold side of intercooler to throttle body.Oh and squeeze a downpipe in somewhere,LOL.
Also got to wait for monthly pays which is a pain,but this pay coming is the one that will get me ecu,injectors and wideband kit.
Cheers Paul.

[Gunni]

Those turbo specs mean nothing without wheel size information.
A/R info is too vague

[polred]

Those turbo specs mean nothing without wheel size information.
A/R info is too vague

Got the wheel sizes today,the inlet is 60mm and ex is 70mm.Could you say roughly what it would be like?,thanks Paul.