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

 

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

 

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.

 

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

 

2002's are awesome 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.

 

I thought he has an inline 6.

 

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.

 

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

 

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

 

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....