ITB's on a stock m20

[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, 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

[steve_k]

Very impressive, what ITB's did you use?

[e21jps]

our own ones www.racehead.com.au

I really wanted to get this onfo out because so many people have a go at fitting itbs and make all the classic mistakes of fitting the wring size and give them a bad name, i made the same mistake years ago and people just dont realize the importance of air velocity. This proves they are capable of yealding some really great gains throughout the WHOLE rpm range on ANY engine, but that is only IF they are done correctly ie.... made small enough to maintain good air speed. Look at the standard manifold, its about 36mm

companies like Dbilis just add to the bad reputation.... i dont know how they can pedal a product that is guaranteed to loose power EVERY time!!!

[reggid]

other thing is the runner length on dbilas from head-manifold interface to the plenum is only 200-210mm (so approx 280mm from valve to plenum) which is far too short for most m20 engines.

both excessively large diameter runners and excessively short runners hurt midrange the most

[steve_k]

So what is the ideal size/length runners for an m20??

I only ask I've got the blueprints for the inlet manifold for ITB's for an m20 off turbo brown but not had chance to print them off & have a good look at them.

[reggid]

So what is the ideal size/length runners for an m20??

I only ask I've got the blueprints for the inlet manifold for ITB's for an m20 off turbo brown but not had chance to print them off & have a good look at them.

depends on the m20 specs and the application.

[steve_k]

fast road, 1mm overbore (2556?cc) griffin motorsport stage 3 head 276dg cam (cat cams) magnex 6 branch, BBTB, X-pipe, soon to be 19lb injectors etc.

so, that any help?? been looking at triumph 38mm throttles (same as bulletride is using).

[reggid]

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

[steve_k]

Cheers digger

[reggid]

i would err on the long side and have a means to reduce the length via removal of spacers etc if you can

[Rav335uk]

our own ones www.racehead.com.au

I really wanted to get this onfo out because so many people have a go at fitting itbs and make all the classic mistakes of fitting the wring size and give them a bad name, i made the same mistake years ago and people just dont realize the importance of air velocity. This proves they are capable of yealding some really great gains throughout the WHOLE rpm range on ANY engine, but that is only IF they are done correctly ie.... made small enough to maintain good air speed. Look at the standard manifold, its about 36mm

companies like Dbilis just add to the bad reputation.... i dont know how they can pedal a product that is guaranteed to loose power EVERY time!!!

I posted a reply on the other forum.

[themaverick999]

so how much for the full set up ? including map, itbs and managment posted to uk?

[Shane_M]

check out the sound they help generate at
[youtube][/youtube]
and how good they look
https://www.facebook.com/kamotors/photo ... 0633553449