E36 328i throttle body conversion....
Discussion
....anybody done it? Is it worth it in terms of increased power Vs worse economy/insurance etc?
I'm in two minds. On the one hand I drive quite hard as it is and I'm starting to notice I make overtaking manouvres I wouldn't dream of in most cars, so on the one hand more power would reduce that time exposed to danger.....or it might mean I start to drive on the right. To do or not to do...
I'm in two minds. On the one hand I drive quite hard as it is and I'm starting to notice I make overtaking manouvres I wouldn't dream of in most cars, so on the one hand more power would reduce that time exposed to danger.....or it might mean I start to drive on the right. To do or not to do...
Have you already removed the restrictor in the air filter box? That's the best place to start.
Throttle body conversion is cheap and easy, so why not do it. For best results also consider replacing the inlet manifold for the 325i one or, even better, the one from the E36 Alpina B3 3.0
Throttle body conversion is cheap and easy, so why not do it. For best results also consider replacing the inlet manifold for the 325i one or, even better, the one from the E36 Alpina B3 3.0
I understand the 325/525 inlet manifold has a very positive effect on the M52 2.8 engine. I presume this is what you mean? I know several people who are very happy with this conversion as the 2.8 was strangled by the factory to differentiate with the 3.0 M car.
There's also quite a lot of stuff about 'foggin' intakes (named after Sean Fogg IIRC), but i'd go for the throttle bodies and a chip as a fisrt tentative step.
I'd also recommend a supercharger conversion on this motor too, but for the extra you could look at a lot of trade ups to standard motors too.
There's also quite a lot of stuff about 'foggin' intakes (named after Sean Fogg IIRC), but i'd go for the throttle bodies and a chip as a fisrt tentative step.
I'd also recommend a supercharger conversion on this motor too, but for the extra you could look at a lot of trade ups to standard motors too.
The airbox restrictor can be taken out by yourself in approximately 60 seconds!
Slide the air filter and it's carrier out of the airbox. On the inlet side of the 'box you'll see a plastic restrictor; simply unclip it and pull it out.
As Stu says, this (great) engine has been strangled to keep the BHP down. This modification allows the engine to suck in more air.
Don't know what gain you can expect; I'd say a couple of horsepower. The induction noise is slightly more sporty, too
Slide the air filter and it's carrier out of the airbox. On the inlet side of the 'box you'll see a plastic restrictor; simply unclip it and pull it out.
As Stu says, this (great) engine has been strangled to keep the BHP down. This modification allows the engine to suck in more air.
Don't know what gain you can expect; I'd say a couple of horsepower. The induction noise is slightly more sporty, too
Hereward said:
The airbox restrictor can be taken out by yourself in approximately 60 seconds!
Slide the air filter and it's carrier out of the airbox. On the inlet side of the 'box you'll see a plastic restrictor; simply unclip it and pull it out.
As Stu says, this (great) engine has been strangled to keep the BHP down. This modification allows the engine to suck in more air.
Don't know what gain you can expect; I'd say a couple of horsepower. The induction noise is slightly more sporty, too
I'd interested to hear from anyone that has tried this - I've heard that by doing this, the balance of the airflow into the engine can be upset, and can cause the car to stutter when cruising along the motorway (i.e. engine at low revs/minimal effort)
turbo tim said:
The airbox restrictor can be taken out by yourself in approximately 60 seconds!
Slide the air filter and it's carrier out of the airbox. On the inlet side of the 'box you'll see a plastic restrictor; simply unclip it and pull it out.
As Stu says, this (great) engine has been strangled to keep the BHP down. This modification allows the engine to suck in more air.
Don't know what gain you can expect; I'd say a couple of horsepower. The induction noise is slightly more sporty, too
I'd interested to hear from anyone that has tried this - I've heard that by doing this, the balance of the airflow into the engine can be upset, and can cause the car to stutter when cruising along the motorway (i.e. engine at low revs/minimal effort)
Yes, I'm a bit wary about that one myself. Sounds TOO easy
My friend here has an E39 528i and we're going to investigate next week.
The 328i power was kept low NOT to differentiate it from the 3.0 l M car but due to the then current German Tax laws. Notice how all Kraut motors from that era, were around 192 Bhp, including the Merc and the Audi.
This is why the inlet system is not only deliberately restrictive but a common part with the 320i. It seems plausible that there is a restrictor in the air box, if the BM engineers couldn't get the power down enough and/or if they were trying to get rid of an intake "boom" (which us enthusiasts would probably love anyway), they probably had a job trying to get this 24 valve motor down to the 12 valve specific motor output levels of 68 Bhp/litre anyway!
They already run a tiny 228 duration inlet cam, but the cylinder heads flow really quite well (about 200 CFM at peak valve lift at 28 inches of water).
The 328i power was kept low NOT to differentiate it from the 3.0 l M car but due to the then current German Tax laws. Notice how all Kraut motors from that era, were around 192 Bhp, including the Merc and the Audi.
This is why the inlet system is not only deliberately restrictive but a common part with the 320i. It seems plausible that there is a restrictor in the air box, if the BM engineers couldn't get the power down enough and/or if they were trying to get rid of an intake "boom" (which us enthusiasts would probably love anyway), they probably had a job trying to get this 24 valve motor down to the 12 valve specific motor output levels of 68 Bhp/litre anyway!
They already run a tiny 228 duration inlet cam, but the cylinder heads flow really quite well (about 200 CFM at peak valve lift at 28 inches of water).
you will get tons of feedback from people who have already done this mod on www.e36coupe.com plus great advice on where to source the best parts.
I,m thinking of doing it myself
I,m thinking of doing it myself
turbo tim said:
I did this on my car and had no probs over 30,000 miles.
Didn't change the throttle body or manifold, though.
Did you disconnect and then reconnect the battery after you had done the work to reset the airflow meter thingy?
Without consulting my manual, that in itself isn't as straight forward as it sounds is it?
turbo tim said:
I did this on my car and had no probs over 30,000 miles.
Didn't change the throttle body or manifold, though.
Did you disconnect and then reconnect the battery after you had done the work to reset the airflow meter thingy?
No I didn't. Damn; did I miss a trick?!
I thought the MAF sensor would self-adjust the various settings to cater for the increased air volume.
Hereward said:
I did this on my car and had no probs over 30,000 miles.
Didn't change the throttle body or manifold, though.
Did you disconnect and then reconnect the battery after you had done the work to reset the airflow meter thingy?
No I didn't. Damn; did I miss a trick?!
I thought the MAF sensor would self-adjust the various settings to cater for the increased air volume.
The MAF sensor will self compensate for air flow changes and the Lamda sensors will ensure the AFR is kept correct.
Every car that rolls off the production line has a tolerance band in terms of how much power, and therefore airflow/Volumtric efficiency at top end each car makes. This mod is likely to fall well within that band so should be fine.
Its been nearly 24hrs now since I removed the restrictor and I have come to some conclusions;
1) The difference in noise when you plant your right foot is unbelievable. The only way I can describe it is that it now sounds like a touring car above 3500rpm. Theres a proper hard edged yet musical induction boom. It sounds like the engine has grown in capacity.
2) There is no difference whatsover in noise in normal relaxed driving.
3) It does feel like there is a bit more midrange and certainly top-end power. This could simply be down to the fact that it 'sounds more exciting'. Hard to be sure without figures.
4) That flat-spot at 2500rpm is still there
5) There are no problems with running at all. No stuttering at low revs. It drives exactly the same. The difference only becomes apparent above 3500rpm, and its a positive difference.
6) If you have a 328i you MUST throw your restrictor from the nearest cliff.
THANKS GUYS!!!!
1) The difference in noise when you plant your right foot is unbelievable. The only way I can describe it is that it now sounds like a touring car above 3500rpm. Theres a proper hard edged yet musical induction boom. It sounds like the engine has grown in capacity.
2) There is no difference whatsover in noise in normal relaxed driving.
3) It does feel like there is a bit more midrange and certainly top-end power. This could simply be down to the fact that it 'sounds more exciting'. Hard to be sure without figures.
4) That flat-spot at 2500rpm is still there
5) There are no problems with running at all. No stuttering at low revs. It drives exactly the same. The difference only becomes apparent above 3500rpm, and its a positive difference.
6) If you have a 328i you MUST throw your restrictor from the nearest cliff.
THANKS GUYS!!!!
apache said:
To really get rid of the flatspot bung in a Viper superchip, it made a hell of a difference to my old banger. The info about putting the 325i manifold on is good advice as well
The thing is I'm not entirely sure I want to completely eliminate that flat-spot. Strange as it may sound. I don't want to alter the character of the car much, and I quite like the feeling of the shove when it comes on-cam at 3000rpm.
Gassing Station | BMW General | Top of Page | What's New | My Stuff