BMW 328 Throttle body mod


Torque Junkie
vw t4 caravelle 2.5
Has anyone heard of the Big bore throttle body and M50 manifold modification that you can get for the BMW E36 328I ??

I always wanted one on mine but never got round to it. Cost effective it's well worth it as it costs about £500 fitted.

Basically, the 328i M52 engine was restricted by stock with a small throttle body to comply with certain Tax laws.

How to get round this ?? . . Make it bigger :D. This with the addition of the M50 manifold, a modified ecu and a decent air filter and the '28 will be pushing 230/240 bhp compared to standard 192bhp.

anyone that has driven a standard 328i will notice that although the car pulls well and has tons of torque it feels strangled and held back.

I'd like to drive one with the mods done. :D
Re: just out of interest . . .

I'm not that familiar with BMW's but this sort of trick is common. Ford did something vaguely similar with the first Mondeo - the 1.8 was gutsier than the 2.0 so they dropped the gears on the 2.0 which made it quick but also very loud.
BMW put a smaller throttle body into the 328 to get more torque in the mid-range of the revs with a little sacrifice of top end horsepower.
Interesting. So which would be better for the daily drive?

It would be cool if you could switch between the 2.
I think the smaller would be better for the daily drive as the torque is higher in the rev area where you drive usually. what do you mean exactly to switch between the two? If you want to change one it takes (I would assume) at least an hour to change. I could be wrong. it might take even longer.
I was thinking of having a twin pipe system with servos that alternate the air flow between the different sizes before the MAF sensor.

Another gimmick might be to have a servo driven aperture inside the air intake to restrict the air flow.

I think TVR, Aston Martin or Porsche developed something like this for the exhaust where the exhaust bore effectively increases at higher RPM.
That would probably be an amazing system. But I personally wouldn't do that to my BMW because I don't have the time for that. But if you want to you could probably do it by playing around for awhile and fabricating something. It would be a cool system to have.
Quite a common mod for 323's and 328's. Quite restrictive manifolds and throttle body at stock. Costs about £400 fitted and I have yet to hear of someone who has done this mod who doesnt love it. Finds a good 20-25hp.
the m50 manifold swap is a cheap and cheerful mod that will gain you 12 bhp alone it is basicily of the 325 model ther is a site out ther and the bloke charges bout $300 it cost me £90 but i choose to have ago my self and yes love it but you do lose your bottom end torque because it moves it to top end power the solution underdrive pulleys best of both worlds .back to the swap once i had the manifold and few bits of hose i was of the best site i came across was emotors but even that was bit tricky in sum stages . but got ther in the end next time my engine in bits i will take a video of the install .
That sounds pretty good. I'm going to do that to some day. It's a pretty good mod to get started with. Even the M3 came with the smaller throttle body. Which is stupid in my opinion. Where did you get that manifold for 90 Pounds? is that in england?
Hi is there a need for a remap with this mod,as i have just got a inlet and throttle body from a 325, for my 328 or will it run ok. Can anyone help thanks.
No you dont have to have the car re-maped just yet i think you should leave it till last because then you will no the difference from the mod . the car will run fine next i would recomend a set of under-drive pulleys to really notice the manifold and throttle body swap hope this helps every one tunning up e36's.
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