throttle bodies , dblias

[themaverick999]

Hi

Found some dblias throttle bodies for sale and wondering do they need megsquirt etc or can I retain the air flow meter as they go into a airbox?

Thanks guys

[themaverick999]

Just like the sound tbh any extra info appreciated

[reggid]

can use factory setup but standalone is better.

is it TB's only or whole kit?

[themaverick999]

It's the, manifold, bodies, Plenum and filter, so can just attach my filter and airflow meter to it?

[themaverick999]

What bhp gains too roughly?

[reggid]

It's the, manifold, bodies, Plenum and filter, so can just attach my filter and airflow meter to it?

yeah but you need to make sure you sort the Throttle switch, vacuum lines and ICV hoses throttle cable most solutions should be with kit you can buy parts separate from dbilas. there are some fitment issues to the thermostat housing and heater hoses but nothing that cant be solved.

not much hp gain unless your a massively modded, the runners are too large for anything south of 320bhp. should be nice and responsive

a good writeup (may need to register to see?)

http://www.e30clubsa.co.za/forum/index. ... -m20-325i/

[themaverick999]

Hmmmmmmmm well over my head, just they are cheap, is this a right mission?

[themaverick999]

Read it and kind of makes sense, cable and studs worries me but not the grinding etc, don't want to buy them then have to spend hundreds getting to fit

[jmc330i]

If its just for the noise, really don't bother. You will get just as much induction sound from one of those expensive (but less than itbs) carbon air box things or a generic cone filter with a decent heat shield to enclose it - drilling the bottom of the standard airbox will also give a deep and loud induction noise!

All of those options cost much less than an itb setup and will produce just as much power (or not) as the itbs on a standard or mildly modded M20.

If its for power gains, I'd not bother again.
For some reason, the M20 doesn't really respond well to itbs, so really need to be running a highly modded M20 (2.7/2.8, lairy cam, headwork etc etc) to get any gains from an itb setup and even then, any gains you do get will be right up the rev range, so would only really be suited to a race/track car that will spend a lot of time screaming its nuts off.

There was a member on here years back that ran the dblias itbs on a highly modded (read expensive) 2.9 stroked M20, iirc it managed to make 250bhp.
Personally I'd rather turbo an M20 or drop an M52 in and be happy with 30 odd less bhp but more money in my pocket to run the thing!

[themaverick999]

Some valid points to be Fair, bad idea then?

[themaverick999]

Also new to BMW's so m52? There is a Turbo motor I have seen too, guess would need cat cams at Least with itbs?

[reggid]

If its just for the noise, really don't bother. You will get just as much induction sound from one of those expensive (but less than itbs) carbon air box things or a generic cone filter with a decent heat shield to enclose it - drilling the bottom of the standard airbox will also give a deep and loud induction noise!

All of those options cost much less than an itb setup and will produce just as much power (or not) as the itbs on a standard or mildly modded M20.

If its for power gains, I'd not bother again.
For some reason, the M20 doesn't really respond well to itbs, so really need to be running a highly modded M20 (2.7/2.8, lairy cam, headwork etc etc) to get any gains from an itb setup and even then, any gains you do get will be right up the rev range, so would only really be suited to a race/track car that will spend a lot of time screaming its nuts off.

There was a member on here years back that ran the dblias itbs on a highly modded (read expensive) 2.9 stroked M20, iirc it managed to make 250bhp.
Personally I'd rather turbo an M20 or drop an M52 in and be happy with 30 odd less bhp but more money in my pocket to run the thing!

ive only seen one or two setups that was ever matched to the engine and about 10 or so poorly mtahced hence results are disappointing. its nothing to with the M20 really just about building engines with everything matched i.e head, intake, exhaust and cam.....

most people are building 250hp engines with the iTB setup capable of 380bhp (i.e. 45mm throttles) hence they never get a benefit and only get an M20 with no midrange torque and no additional peak power

[e30topless]

What bhp gains too roughly?

None ! you will only gain space in your wallet !

but they do look cool

[jmc330i]

If its just for the noise, really don't bother. You will get just as much induction sound from one of those expensive (but less than itbs) carbon air box things or a generic cone filter with a decent heat shield to enclose it - drilling the bottom of the standard airbox will also give a deep and loud induction noise!

All of those options cost much less than an itb setup and will produce just as much power (or not) as the itbs on a standard or mildly modded M20.

If its for power gains, I'd not bother again.
For some reason, the M20 doesn't really respond well to itbs, so really need to be running a highly modded M20 (2.7/2.8, lairy cam, headwork etc etc) to get any gains from an itb setup and even then, any gains you do get will be right up the rev range, so would only really be suited to a race/track car that will spend a lot of time screaming its nuts off.

There was a member on here years back that ran the dblias itbs on a highly modded (read expensive) 2.9 stroked M20, iirc it managed to make 250bhp.
Personally I'd rather turbo an M20 or drop an M52 in and be happy with 30 odd less bhp but more money in my pocket to run the thing!

ive only seen one or two setups that was ever matched to the engine and about 10 or so poorly mtahced hence results are disappointing. its nothing to with the M20 really just about building engines with everything matched i.e head, intake, exhaust and cam.....

Sorry, I should of said a standard, untouched M20.
People see Vaux 16v red tops or the Pug 106 GTis make good gains with itbs on an otherwise standard engine and assume the same can be done on every engine.

You can build an M20 to make good power on itbs, but as you say, you would need to match everything to get the best. The only issue is, the engine would pull well at either low or high rpms, not both - depending how the engine was built (size of throttles, headwork etc).
To get the best from itbs, you would ideally have variable valve timing. That way the timing/duration of the cam can be such to produce the low down torque, and then altered to make the most of the better breathing itbs at higher revs.

Another issue I've seen (not necessarily with the dblias itbs) is that people over size the throttles for the M20. I think people forget that the cylinder capacity of the 2.5 M20 is the equivalent of a 1.6l-1.7l 4 pot engine. People try to use the E36 M3 itbs on the M20 forgetting that the M3 has a cylinder capacity of a 2.0l 4 pot - might be great for a high revving built monster M20, but shite for a mildly tuned road going M20.

I once had some itbs from a 106 GTi that I was going to experiment with on my M20, but a lack of time, money, enthusiasm (and the fact I only had 4 itbs for a 6 pot lump) meant I never did anything with the idea
I'm sure it would be perfectly possible to make an itb setup for the M20 that would work on a fairly standard/mildly tuned engine - but, if the only upsides are improved throttle response and a lovely noise, I can't see it being worthwhile pursuing.

[HairyScreech]

Also adding to the party is the fact the m20b25 has mahooooosive ports for its air consumption which adding ITBs to only really compounds the issue with a short intake length.

[reggid]

on a standardish M20 you wouldn't bother the factory ALu job is capable of 260bhp but not much more, another advantage of ITB is you can run much bigger camshafts without as much compromise to idle and low speed drivability since you don’t get all of the cross talking happening and possibly the throttle blade produces nice fuel mixing close to the valve.
There was a 2.7L maybe it was oakeys that had a ITB setup (somewhere around 36-38mm from memory) with nice torque curve a lot better than with the factory manifold.
i would always look at hp/cylinder for sizing throttles since hp is basically airflow and airflow /area is velocity. There are certain velocities that make the best volumetric efficiency it is neither slow nor fast but just right but still some compromise need to be made to make good torque from 2000-6500.
A 3.2L S50B32 uses 50mm IIRC and can make 450-500bhp with that size. On a 6cyl 3.2L M20/M30 engine only making 300bhp you would not use 50mm something closer to 40mm will have the same velocity
50mm* [(300hp/450hp)^0.5] = 40mm and for a 250bhp engine 37mm
Since the inlet tract ideally tapers the close to the head the smaller the throttles so this is a consideration to. You don’t much taper on a low rpm engine a couple of degrees is plenty.

[themaverick999]

This has been a real help and learnt quite a lot about the engine configuration Thanks guys

[Steven320]

hee guys, a frend of my is building for me a slide itb's, but i cant find where i can calculate the ideal distance between valve and center of the tb, can some one help me with that.

greetz

Steven

[reggid]

tell him to buy a set from e21JPS

http://www.e30zone.net/modules.php?name ... c&t=245031

[steve_k]

Also have a look at bullet rides "I can go with the flow" thread as he's building an ITB set up for his m20.

[NoTurbo]

very cool thread guys..