BBTB?

[SilverShadow]

Where can I buy one for my M20 engine?

Wiki says you can buy from the zone but can't seem to find a thread on it?

[jimbom30cab]

Pm to maggspower

They work well in a m20

[JungleGus]

http://www.e30zone.net/modules.php?name ... highlight=

it's just attached to an Engine =)

[pony]

How much is BTB ?
How much bhp does it add ?
Does it add 14 bhp ?

[bhups]

LOL

[Grrrmachine]

Pony, BTB is an exhaust stysem. BBTB is a big bore throttle body.

Together, with the right chip, they might add 15hp.

[SilverShadow]

Does anyone have to hand the diameter of the bore on a standard throttle body and a BBTB?

[jimbom30cab]

The BBTB makes it fell much more responsive and probably doesn't add any bhp

with a light flywheel it really livens up the m20 lump

well worth it in my experience

[pony]

Barry has BTB
Factory output he has dynoed his at 171bhp
With BTB 184bhp

[pony]

The BBTB makes it fell much more responsive and probably doesn't add any bhp

with a light flywheel it really livens up the m20 lump

well worth it in my experience

The e30 I drove of yours has super light flywheel
Felt linear and smooth
Quicker than mine albeit mine needed downpipe gasket replacing

[reggid]

Doubt a BBTB adds any Hp, it is more responsive due to a higher exposed area for the air to flow through for a given throttle angle input, but this at the detriment to throttle resolution i.e. effective WOT at low rpm is even further below true 100% WOT than it is with the standard throttle.

BTB is much more worthwhile but you will be selling a kidney for one especially if no GB

[zaust]

This is providing you match the inlet on your manifold to match the tb, if not that nice extra surface has air rushing down the out side lip Then hitting a wall and vortexing towards the center and would slow you down if anything. Especially if you were say doing 40 mph and wanted to get to 60 you would feel the nothingness of torque. If you were at stand still and floored it through the gears it would work.

[jimbom30cab]

Zaust, i hear what you say and respect you have a lot more experience with these cars than me

However, an BBTB on a M20 makes a very noticeable difference at any RPM,

I've got 4 BBTBs on M20x2 (2.5 AND 2.7) M30 and M52 and experimented with and without them (as the only mod)

They make a very noticeable difference to the pick up at any RPM on an M20 in fact the 40 to 60 shove in 3rd gear is MUCH more responsive.

To be honest it didn't make much difference on the M30.

[zaust]

I have had them on all my cars mostly m20 and currently on my m30. I have matched the inlet mouth and there was a big difference in pick up with all.

With the flow of the air lets say 4th and 2500rpm or so and put your foot down, there will be a back log of air until the swirl finnishes and the rush starts. if you went hard from 3rd to 4th you won't notice due the air already flowing at a much greater force.

Not saying they don't have any improvement in genreral but you need to match the inlet to see a real gain in response. It's like putting on b12's and fitting ecp springs with them.

[jimbom30cab]

I see, yes that makes good sense

[ross_jsy]

Would be interesting to see a before and after dyno run, not for peak power but power delivery and the torque curve

[zaust]

I was just having a search for eta's one, but the pic's of the graph no longer show.

He was down 18hp after the bbtb was fitted but had air leak problems.


Would be good to see a fresh one though. Ross the peak power should not change but yes the torque will.

[daimlerman]

Does anyone have to hand the diameter of the bore on a standard throttle body and a BBTB?

A standard T/B is bored out to form the BBTB,so the increase in thottle area is limited to the amount of material that can be safely removed from the body's bore,go too far and the thing collapses.

Other thing to watch for is to make sure that the butterfly is fitted correctly,there should be no gaps around the edges.

I noted a 5% improvement in fuel economy with mine.

[SilverShadow]

Thanks daimlerman, I wanted to check the current bore size on my TB to see if it has not already been converted.

[daimlerman]

Thanks daimlerman, I wanted to check the current bore size on my TB to see if it has not already been converted.

Easy way to check;

At the lower r/h side(from memory!)there's a bit sticking out,no idea what it's for,this gets removed when they are over-bored.

[zaust]

60mm not and 64mm max bored on m20, also from memory.

[jimbom30cab]

yes, i saw an improvement of 2mpg over a couple of tanks when i put one on a M20B25 with no other mods.

Has anyone got any experience of before and after M50 BBTB on a M52B28, i've never had a normal TB so just wondering if it makes a difference or not.

[daimlerman]

60mm not and 64mm max bored on m20, also from memory.

Standard one in my parts stash measures 63mm,without getting the cabbie out and stripping the thing I cannot give a measurement for the over-bored one that I have fitted.
('er indoors has a line of washing across the workshop door ATM!)

[reggid]

the bore at the throttle is 60mm stock the entry and exit is more like 63/64mm so its tapered in and out.
With a BBTB usually the bore is 63mm but this can differ depending who does it and the entry is 65 but made into a sharpish edge and exit 65mm.

[maggspower]

As above, the standard throttle is tapered. The size of its butterfly across the line of the spindle is 60mm.

My ones are then bored out to 64mm, and the taper is then reinstated on the AFM side of the throttle.



There is a lot of other info on the group buy thread:

http://www.e30zone.net/modules.php?name ... 70&start=0

I have 2 enquiries for throttles at the moment. If there is any one else that wants one I would do a mini group buy, and it will come in a bit cheaper, 5 people needed.