Author Topic: ITB's info/projects  (Read 147194 times)

Darky

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Re: ITB's info/projects
« Reply #150 on: October 30, 2015, 12:00:38 AM »
e36 m3 itb's. i had a spare m42 head so could work out where everything had to go without taking the inlet off my car. i removed the centre pair of throttle bodies and used the 2 outside pairs, cut down the throttle linkage and fuel rail then had to have 2 pieces of aluminium welded to the bodies where the studs didn't line up. the ports matched great but the studs needed re drilling. i used the m3 tps and injectors and the engine started ok without the air flow meter but was too rough to drive
https://youtu.be/JkjyEIHgQLE
the trumpets were made from exhaust tube and egg cup holders (very low budget)
i didn't want to run the restrictive afm so i made a loom and fitted a DTA ecu. once mapped it ran really well, it sounded lovely but didn't make much more power than standard. it was fun to do and cost very little apart from the ecu. the biggest gain was in the sound it made, it sounded like 200 bhp
i will post pictures when i can work out how to make them smaller


Hi

Sounds like a bit of fun, but you wouldn't have the air velocity for this to work properly.
Couple of things that would help are 34 mm inlet valves same as s50 and larger individual cylinder volume ie stroker. Also note that s50 itbs where designed to be effective at a very high rpm, hardly that useable on the street. You look like you have extended the trumpets though.

Another thing to consider is valve size to itb size or more accurately areas
E30 m3 2*37 mm to 46 mm trumpet
E36 m3 2*34 mm to 48 mm trumpet

Can you see what's a bit off? I'm still trying figure that out.
I think they used the 6 cylinders timing to bounce shock waves from one trumpet to another.

Cheers Rohan

jerseytim

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Re: ITB's info/projects
« Reply #151 on: June 16, 2016, 03:20:52 PM »
that video was with the standard ecu and i wasn't running the air flow meter, i couldn't drive it as it was. it flying now wit a dta ecu, still using the e36 m3 itbs and egg cup holder trumpets. I'm very happy with everything about the engine now. 2086cc and 216bhp  https://youtu.be/u_IGiDsIbk0

jerseytim

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Re: ITB's info/projects
« Reply #152 on: June 11, 2019, 12:05:23 PM »
i had an exhaust manifold made to the engine tuners spec and fitted it onto the car, it took a long time to fit as the engine had to come out and additional holes drilled and tapped in the head as the m42 only has 3 holes per port and the new manifold had 4. once fitted i took it to a rolling road to get it remapped and it made 257.4 bhp which i was very pleased with. The guy who built the engine is keen to replace the cams and up the revs as he thinks he can sacrifice some of the torque now that i have a close ratio gearbox. you could really feel the difference with the new manifold. unfortunately the engine has now gone into my e30 and the manifold was not going to fit so i have had to replace it with an eBay one that also needed lots of modifying to clear the steering column
https://youtu.be/8sduHpRjnk4
the eBay manifold

the handmade manifold

dimiras

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Re: ITB's info/projects
« Reply #153 on: January 27, 2023, 11:22:46 AM »
Are 38mm throttle bodies good for a itb setup in a fairly stock m42?