M20 ITB's

[e30leigh]

man wish i had itb's. these setups look awesome!

[mr ilia]

I'm using the same tbs on my m42 itb setup and s14 intake plenum. hopefully will done by spring. Everything is custom in my build and not all tools are readily available. It takes time to work out little things.

New setup in progess: 38mm BMW 1200RS Throttle Bodies






This is still a work in progress but I know another person on here has a completed setup using the same bits, and it's running well. 38mm should be able to outflow even a well worked intake port easily while still maintaining proper port velocity. Another plus is it allows the throttles to be placed very close to the head, taking up less space and allowing for a proper plenum.

[digger]

When you get a chance I would be very curious to see how 38mm throttles ~1-2" from the head would work on a 3.1L stroker, compared to 40mm or 42mm. Hopefully I didn't "choke" it down to much.

a 210hp M20 only needs 32mm diameter at port entry so the fact that the stock 885 is about 38-39mm at the port means it is too big already.

38mm would work fine and can support 300bhp which needs a head that flows ~200CFM @ 0.450-500"

[F34R]

That makes 2 of us then, I suspect there are many others that feel the same way. Comparing an S54 to an M20 is not really what the point of this thread is.

I went the built m20/boost route instead of buying a S52. So that is another loony person on the list.

S54 is amazing, but it is not built as well as a m20. The cost of the piston rings alone are stupid expensive.

I think the work involved in a cam'd, built out the ass m20 with boost it much more amazing than a swap.

[bradnic]

this thread is friggin awesome. sub'd hoping for future posts

[bradnic]

Anyone want to comment on the ITBs used on the Hartge H27SP? I found this over on e30zone. note runner length, plenum. Seems like it would perform better than dbilas. Hartge claimed 220HP with 2.7L and 10.2:1 CR.

[digger]

Anyone want to comment on the ITBs used on the Hartge H27SP? I found this over on e30zone. note runner length, plenum. Seems like it would perform better than dbilas. Hartge claimed 220HP with 2.7L and 10.2:1 CR.

the runners look pretty fat still, where does the linkage go?

[bradnic]

Here are some more pics I've found

[bradnic]

Wow one of these just sold for $1600+ on ebay.de last month. here are the pics









the plenum doesn't look any bigger than the dbilas. the runners are much longer though.

[tinkerputzer]

That hartge itb set up is pretty interesting. I like that it installs cleanly and clears the booster. Is it really any better than the stock manifold though? All the air that enters the plenum still has to come through that single intlet which doesn't look much bigger than the stock throttle body.

[bradnic]

That's exactly what I was wondering.. but dbilas does the same thing really.

btw it turns out they couldn't be in better hands... e30m3s54turbo (Raul) bought them. He told me they are the only set he's ever seen for sale.

Maybe one of you guys down his way can take a closer look at the setup?

[TobyB]

...it always seems to come back to the 2002tii, doesn't it...

t

[LJ851]

...it always seems to come back to the 2002tii, doesn't it...

t

The tii is mech injected, common plenum, single throttle plate...


Not really seeing the connection ??

[e21jps]

Here is an example of a back to back test we did fitting a set of our ITB's to a stock standard 325i engine, this is a high milage engine and the only modifications are a set of average headers and a single tail pipe

base power was 112Kw or 150Hp which is about right looking at other peoples results

We fitted a cheap ($800) stand alone ecu (called and EMU which by the way seems very good) and a set of our 40mm itb's, power went straight to 130Kw (174Hp) thats better than a lot of 2.7 strokers or engines with cams and other mods etc

To back up these results and make sure it wasnt some other irregularities we went to a different dyno and tested it again with the same result 129Kw

Note that it didnt loose any torque down low it gained everywhere from about 90Kph, which is probably where the operator hit full throttle. The mixtures are rock solid running purely as Alpha-n (TPS load control), more stable than the motronic was.

so there you have it.... a good ITB is worth good power on ANY engine if its done right and you wont loose any torque or drivability

[LJ851]

^ Thank you for the real world, back to back testing.