Turbo 525 Conversion?

[Spasso]

Hi guys,
Being relatively new to the site and mostly lurking, I have seen mention of the 745 turbo conversion for the 535 engines. Is there a similar conversion for a 94 525?

I am mainly curious if a moderate boost system is available, 6 psi max or thereabouts..

Most of the searches I have done have netted information on 10 to 18 psi with massive intercoolers. Not interested in that.

Thanks,
DJ

[RobPatt]

think your sig or whatever says you have a 530?

anyway w/the 94 engine inyour 525 you got vanos... so limited in the rpm dept... your sig also says you have an auto trans, another limfac depending on how much torque that thing can take.... my M50TU w/EAT is I guess about 200hp and 200torque (foot pounds)... meanwhile the stock GM tranny takes only like 3.1 or 4.1 (forget but its the BMW nomenclature for the transmission) Nm of torque, which calcs to about 225ft/lbs... so no turbos for me with that stock tranny in there...

JonK on the board here is the FI guru having supercharged and turbo'd M50 engines, but think the latter was a non-vanos....

guess you could do low psi 6-8 but will the tranny last?

Hi guys,
Being relatively new to the site and mostly lurking, I have seen mention of the 745 turbo conversion for the 535 engines. Is there a similar conversion for a 94 525?

I am mainly curious if a moderate boost system is available, 6 psi max or thereabouts..

Most of the searches I have done have netted information on 10 to 18 psi with massive intercoolers. Not interested in that.

Thanks,
DJ

[Spasso]

I have a stock 530ia.
I am looking at a '94, 525iT. I was looking at the possibility of mild boost to improve the overall performance of the car without over stressing the engine and transmission. Maybe a net HP in the 230/240 range.

Nothing really radical...............................

[SnakeyesTx]

I'm pretty curious why vanos is limiting the rpm range effectiveness of a turbo. Isn't Vanos is basically just variable valve timing like the Honda Vtec? This is supposed to get more air/fuel into the mix which you can noticably feel around 3400rpm. What's wrong with putting a little boost in there too?

[Spasso]

Good question.

[jjdickm]

I've heard of people using the manifolds from the turbo diseal on the m20. I would just make my own low boost kit you can just find a manifold and a small turbo slightly larger injectors and possibly a new ecu and your good to go. I would suggest running an intercooler it just better for you engine. I actually setup a 745i kit on my 535i and was not satisfied with the inefficiencies with the components. I would suggests going custom and you can get much better result. Have tou looked up TCD they make bolt on kits if you would rather do that.

[Jon K]

I'm pretty curious why vanos is limiting the rpm range effectiveness of a turbo. Isn't Vanos is basically just variable valve timing like the Honda Vtec? This is supposed to get more air/fuel into the mix which you can noticably feel around 3400rpm. What's wrong with putting a little boost in there too?

I can't write too much here, as I am packing to go home on turkey break. But, one thing to keep in mind is that a VANOS motor and non VANOS motor are different in more ways than just VANOS control. The VANOS motor is 10.5:1 compression, making it less happy when it sees boost. Its still doable, but that extra .5:1 compression works against you. Additionally, VANOS motors have a 228 profile cam, while NON VANOS has a 244 - more ideal for boost. Again, the VANOS has 6mm valve stems vs NON VANOS having 7mm stems, and most importantly, the VANOS has single valve springs while the NON VANOS has double valve springs which help the car rev MUCH higher - I've had my motor up to 7500 rpm.

The harder part is controlling vanos - unless you know how to program the stock motronic DME, you need an aftermarket ECU. I am running full fuel and spark control on MegaSquirt EFI, and don't have VANOS to worry about trying to control. Its tricky - though its just a on/off solenoid, it makes your timing figures and VE table tricky.

Do not expect to just bolt a turbo, exhaust, and charge piping up on these cars and using the stock ECU and upping the fuel pressure. It's more complex than that and you will not have a well-driving car should you do that. It takes a lot of work and a lot of thought - both of which I can share later when I get home from school, but for now I will leave that for you guys to consider.

a '92 525i is probably the best platform to start this on other than a 535i or something without VANOS worries.

[Spasso]

Thanks for the insight Jon. I hadn't considered the aspect of how Vanos would affect the difficulty of installing a set-up. That's probably why a search didn't yield much info on it.

[RobPatt]

Yeah, thanks Jon, I learned all that from following your S/C and Turbo exploits.

Thanks for the insight Jon. I hadn't considered the aspect of how Vanos would affect the difficulty of installing a set-up. That's probably why a search didn't yield much info on it.

[Jon K]

No prob guys - its not that it can't be done, its just that if you want to retain the factory ECU, it isn't the cheapest.

As for hardware, the new versions of SS Autochrome manifolds can be had on Ebay for like $150 - I am running one granted I have an "up pipe" from it to the turbo, but so far so good. The exhaust will have to be custom made most likely unless you buy a TCD M30 exhaust and modify it to fit whichever turbo you go with.

If I were you, I'd not even bother looking at kits because nothing is goign to fit an E34 525 properly. You'll need custom charge pipes, exhaust, intercooler. Then, you'll need big injectors and some sort of standalone. Not to mention wastegate, turbo, BOV, etc. It can be done for cheap, but not easy. Or, easy but not cheap.