ASC delete with 3.5 HFM, which elbow boot?

[M_Dudey]

so I just installed my m50 manifold and it's pretty easy to get rid of ASC. all I need is the 98 roadster elbow boot. I plan on doing the 3.5" HFM in the near future. will the 98 roadster boot fit the 3.5" HFM? if not, which one will? I'd rather get one that will fit the 3.5 HFM now than having to get another elbow boot later.

[TCG///M3]

You will have to get a reducer that goes from the HFM to the intake elbow. It is a plastic piece that fits onto the end of the HFM and then decreases in diameter to fit inside of the intake elbow boot. Eurosport sells the reducer you will need. www.eurosporthighperformance.com

[M_Dudey]

is there an elbow boot that is 3.5" that will work with the 3.5" HFM so that no reducer is needed? seems kinda useless to get a 3.5" HFM and big bore throttle body if the boot will remain the restriction.

[Serious]

none.

[jtgm3]

Where can i purchase a 98 roadster boot to delete the ASC? Is this the only year? I have a 99 M coupe and I believe it has the ASC. Anybody got pictures. Thanks

[djarum]

I'm planning the same install on my 98...I got the 3.5 hfm and m50 intake, I was wondering what software you were going to be running to handle the 3.5 hfm...
Thanks

[SG_M3]

If you have done the m50, get the 95 m3 boot. It has an extra hole to plug the sensor that gets left out during the swap. Makes it cleaner. Or you can use the 98 m roadster boot, and leave the sensor in the engine bay.

[M_Dudey]

so let me get this straight:

I did the m50 manifold swap on my 99 m3. IIRC, the elbow only has one hole for the hose that goes to the ICV to plug into. what sensor are you talking about? what does that sensor do?

[jtgm3]

I still don't get it either. The ASC is a metal piece, right? It's like a throttle body because it has a butterfly in the middle. Why would I need a rubber boot from a different year?

[M_Dudey]

the ASC is the traction control system, which includes that throttle body to close off air intake when you spin your wheels. the point of this mod is to get rid of ASC all together because

1) some people do not want traction control
2) the ASC throttle body gets in the way of air flow

with ASC throttle body, you'll notice that the boot connecting the MAF to the ASC throttle body is only 45 degrees. if you remove the ASC throttle body, you need a boot with a full 90 degree bend to connect the MAF to the actual throttle body.

that is why in doing this mod, you are replacing the metal ASC throttle body with a rubber elbow boot from a car that has the 90 degree boot.

[jtgm3]

Thanks, so it's just a longer boot. Got it. What about the holes underneath the boot? There's 2 instead of 1. What do I do with the second one?

[M_Dudey]

I'm wondering about the holes too. I swear on my 99 m3 with ASC, the boot had one hole that the hose to the ICV plugs into. I don't remember there being a hole for a sensor? so that's why I'm still trying to clarify between the 98 roadster boot (1 hole) and the 95 m3 boot (2 holes?). someone clarify please?

[jtgm3]

My 97 M3 boot is actually ripping because of my nitrous line. I'm thinking of taking the nitrous off, so I bought a boot on ebay for around $20. It came and had 2 holes. My stock had one hole. The boot came off a 92 325 I believe. I was pissed and didn't know about it. I guess I'm going to use it after all. I guess I'm just going to have to block it somehow, although that might be dangerous =).

[jtgm3]

doesn't the 98 M roadster have the ASC? I thought all 96 and up do. What would happen if the ASC is on without the butterfly in it? Would it throw a code?

[jtgm3]

http://www.bmwhow2.com/techarticles/ASC/first_modification.html

just found this.