turbo sizing...for a 2liter BMW engine
 

I am a newbie to the world of turbos but have been reading and learning a lot.

In the process of building a turbo engine for a 1970 BMW 2002...it is a 2 liter engine, 8.5:1 compression, and a 292 cam.

I am wondering what size turbo I should run. Just a t3? maybe a/r .48 range or should I be running a hybrid t3/t4 style turbo.

I am looking for around 190/200hp (car stock is about 110 at the crank) with redline at 6800. I don't plan to run HUGE boost, probally in the 7-10psi range. If 200hp is not achieveable with that I will be ok with less power....looking for smooth reliable power.

I would like a nice smooth power band, 3k(2500ish) to redline would be great.

I will be running megasquirt with edis igition...so I will have full control over fuel and spark. Also will be running a air to air intercooler (15" x 13" x 3" range...)

What would you all suggest? I am interested in both new/rebuilt and used. If anyone has something that fits my motor please contact me.

TIA,
Jake

'70 BMW 2002
'89 BMW M3

Re: turbo sizing...for a 2liter BMW engine
 

is it an inline 6? and that compression ratio is made for boost. t3/t4 sounds good but your hp goal is low so a t3 is alright and btw, read this https://www.homemadeturbo.com/forum/...?topic=37464.0. now post pics of what you're working on

Re: turbo sizing...for a 2liter BMW engine
 

Nope...this is a 4 cylinder...
RWD...

info on the car...
1970 BMW 2002
H&R sport springs
Bilstein sport shocks
adjustable front camber
...coming soon
new engine
bigger sway bars
front strut bar
5 speed trans
3.91 lsd rear end upgraded from a open 3.64
oh yeah...a turbo!

So it should be fun.

Thanks for the link...I will read and do some math.

What are the advantages between just a t3 and a t3/t4?

Jake...

here is a picture of the car before the suspension changes.
This car also went through a 16 month body restore.

http://theguestroom.net/car/11-07-04/02right.jpg

Re: turbo sizing...for a 2liter BMW engine
 

its a four cylinder, my old neighbor has one. T3 42/48 would be a good match. T3/T4 ?? i think that would be way to big.

p.s. i love how the exhaust is in the middle

Re: turbo sizing...for a 2liter BMW engine
 

2002's are awesome :y For your setup a regular cheap T3 will work well and the .42 .48 would put you near your spool up times.That or a DSM T25 will def spool that quick and probably hold on till 65-6800.The T3 is nice as a upgrade in the future means just swap out turbos and not changing flanges etc.

Re: turbo sizing...for a 2liter BMW engine
 

I thought he has an inline 6.

Re: turbo sizing...for a 2liter BMW engine
 

Sweet car. I love old schools my neighbor had one and I wanted to buy it when they were moving out but he brought it with him. Its funny how you mentioned it went through a 16month restoration and I just noticed the driver side door iswaay off. t3/t4 turbos are hybrids which have a t3 exhaust housing and a bigger t4 compressor housing.

Re: turbo sizing...for a 2liter BMW engine
 

The hood was open a little in that picture....the reason the door looks "off"

So just a standard t3 would fit what I need?

jake

Re: turbo sizing...for a 2liter BMW engine
 

the hood was open? how does it open back to front? looks like its shut to me.

Re: turbo sizing...for a 2liter BMW engine
 

Perfect turbo setup would be anything from a 1986-1993 Saab 900, which had similar stock CR. Try to find a water-cooled turbo from the later years, because regardless of what you'll see here, you WANT the extra cooling capacity. (I'm not a believer in the whole cheap-as----- ghetto turbo philosophy. I like to do it once and do it right.)

You should have enough room for a smallish Saab Blackstone intercooler too....

Good thing is that these are REALLY plentiful.

You can run a bit more boost than you think with that low CR, so a T25 might be perfect...A T3/T4 hybrid has more top end, but takes longer to spool.

Since you have to fab up oil and water lines anyway, you might consider a later Mitsu unit, a TD04HL that spools even faster than the Garretts.

You'll have the ultimate sleeper....