Extrude Honing Intake & Big Bore TB

[winstontj]

Does anyone have the measurements of a stock intake bore?

I was talking to the PO last night about extrude honing and he mentioned that the PPO had done a lot of intake and exhaust work (heated wire MAF, e36 Ansa exhaust adapted) so I'm not sure if I need to worry about doing this.

Where can I get extrude honing done? What bigger bore TB do you guys use?

I know I have a stock TB but not sure about the intake. I don't want to spend the $ to get it done on a second intake if the one on the car is already done.

Thanks for any input.
TJW

[NC325iC]

IE does it but its expunsive

[nando]

there is really only one place that does extrude honing - they have a patent on it. everyone who "sells" this service is really just charging you to send it to them.

as far as the BBTB goes, there used to be a BMW guy who did this, but I don't think he's around anymore. any competent machine shop should be able to do it quite easily though - basically turn out the throttle body and make a larger plate to fit inside.

[Mystikal]

Extrude honing does wonders for the 5000+ power of these cars.

No idea on gains for the TB, but as nando said any machine shop can do it.

[NC325iC]

theres always the BBTB that budget beater was always talkin about

bmp used to have one

[Massive Lee]

Extrude Honing is a patented process that does marvel with intake manifolds where machining is not possible. For throttle bodies, you should simply have a machineshop bore it.

[winstontj]

How do I tell if this has already been done? I need to purchase a second stock intake manifold as a spare or incase I build another motor but if I pull the existing manifold on my car now will I be able to tell if something has been done to it?

Also the stock TB is pretty thin walled... How much do they gain when they bore it? I would have thought that you guys would make an adapter plate and fit a different bored TB that was stock and bigger from a 5,6 or 7 series...

[winstontj]

Here's another question regarding BBTB's...

Do you guys know what is done to compensate for the low end? Is there a different cam or lever system to control the opening at low end better/slower? I have a feeling that I could have a bored TB because it measures out almost 5mm larger than my other stock ones. Also the throttle plate is a little different. With that said my low end suxxx. Low end drivability is really poor. I'm wondering if there is a different cam profile that I can use so the throttle plate opens more gently to increase low end drivability. Right now the car drives like it has an ON/OFF switch. Either idle or WOT but very poor in between. If I can not change the low end I'll go back to a stock TB.

Also the intake was extrude honed and the TB was bored out. I wish I knew what all has been done to this thing... I have no idea who the PPO is/was and the PO has no idea. PO things that his "seat of the pants" dyno puts the car at over 200hp and at least 200 to the wheels. He's got an e36m3, an M5, M6 race car and is building an e36m3 track car as well. He knows what he's talking about but I just can't see 200whp out of a stockish (at least displacement) M20 can put out that much.

Thanks for reading... Any thoughts??