Quick OBD1 Convervsion Question

[tjcm3]

I'm in the process of collecting all the recommended parts for an S52 swap into my '88 M3 including the OBD1 conversion. My question is with regard to the required OBD1 Throttle Boot. From photos it appears the difference is that the OBD1 boot has two vacuum ports while the OBD2 (non-ASC version) has only one.

Why the need for two ports? What gets connected other than the ICV hose?

[mentaleeill]

crankcase breather. you can just run a filter and catch can though if you already have the boot with 1 hole.

[ZiMMie]

on the obd1, the other hose comes from the crankcase.
on the obd2, the crankcase hose goes into the top of the ASC-T thingy.

[tjcm3]

Thanks guys - nice to have options.
Speaking of crankcase breathers has anyone used expensive Plenum Adaptor sold by Bimmerworld? I appears to be a very clean way to adapt the OBD2 PCV system to the OBD1 intake manifold, but definitely a little pricey.


Sorry couldn't post an image. Here's the link (item is midway down page): http://store.bimmerworld.com/shared/...t=products.asp

[BigD]

You don't have an OBDII E36, don't waste your time with that stuff. These kits are for people with 96+ E36 who want to put in the M50 manifold - it's not that simple for them, unless they wish to convert to OBDI, which is a step backwards.

My PCV "adapter" is a chunk of coolant hose.

[tjcm3]

I am converting an S52 to OBD1 but I will likely go with the hose and 'T' fitting approach. I really like this machined adaptor for how clean the installation would be, but it would need to be more like $200 to be tempting.

[BigD]

I am converting an S52 to OBD1 but I will likely go with the hose and 'T' fitting approach. I really like this machined adaptor for how clean the installation would be, but it would need to be more like $200 to be tempting.

Once you put the motor in and see how cramped the intake area is, you'll be happy you didn't spend $200 to have a bunch of extra shit hanging there.