M42 + s14 TB's

[boostboss]

I am trying to find any technical drawings of an s14 head or the throttle body manifold flange (where it conects to head).
The bore is noticebly larger from s14 (2.3) to m42 therefore the inlet track spacing would be further apart, right?
I would like to have the s14 individual throttle bodies on my m42 with the addition of cams. I need the tech drawings to see if it is even feasable to achieve even with a adapter plate.

Please help.

[Streetspec_iS]

hehe, yu think good.

eric(e9nine) and i have been talking about this sort of thing for a while. reccently we saw a set of s14 ITBs which were fitted to an m44. they had an adaptor plate welded to the ITBs which fit the m44 head.

cant helpyou with any tech drawings, but keep me posted or get in touch if you wanna nut some stuff out.

[hoofmonger]

i would also like 2 hear about this

[hamann318is]

Same! :up:

[boostboss]

Yeah i was just thinking about an adapter plate or even trying to match port it as best as i can.
Any info on the m44 would be appreciated.
I just really want to know the dimensions of the s14 ports, even a gasket would help.

[e9nine]

Its in its infancy stage. I have taken the intake mani off on my m42 a few times already and based on what I saw, its a matter of simply getting the port dimensions of the s14 head, having a competent machinist fab up an adapter plate and move on from there.

You will have to figure out how to route the vacuum lines from the new setup. This shouldn't be too hard but those vacuum lines are really essential. They affect coolant flow, fuel pressure (I think?) & crankcase ventilation as far as I remember.

I really would've loved to take pics when I had the intake mani off but I didn't have a digi cam avail at the time.

There is one vacuum line which is after the TB which is a real small line used for fuel pressure. The other two lines are for the coolant set up.

If you have a high mi m42 and haven't done these vacuum lines yet, just pull of the intake mani and get them all done, they were the cause of all my idling issues and are really not that hard to replace. THey get oil soaked pretty easily and are overlooked by most.

Back to the ITBs 8)
You can either setup a system using the S14 airbox mated to runners and fed through a master TB or use the ITB setup. :twisted:

Runner length and dia are also something we want to make sure are calculated right

[boostboss]

Yeah my idea is to use the complete intake off a s14 and simply try to adapt the ITB's to the m42 head.
thanks for the info.

[skat 325is]

Friend of mine tried this but he was so lazy he dropped the project and sold the TBs, that i remember you also have to re position the TPS in the TBs. Basically what he did was had a machine shop make him a spacer to make the TBs fit the head, cut and solder a lower part of the air box because i think it was the break fluid reservoir was in the way. He gave up because there was a vacuum leak somewhere and he never found it and gave up. Thats all i remember.

[Rob]

the real question is the work and extra complication of ITBs worth the trouble?

[e9nine]

the m42 is very sensitive to vaccum leaks.
With a project like this, there will be trial and error trouble shooting.
The vacuum hoses are of diff sizes and sources. You have to try make sure the vacuum is almost close to stock. Also make sure you use an m42 TPS since its unique to the ECU with regards to its signal.
Since you be feeding more air in, you might want to re-adjust your AFM spring tension too and also tweak fuel a lil bit as is needed.

[e9nine]

the real question is the work and extra complication of ITBs worth the trouble?

It depends :twisted:

[Streetspec_iS]

the other option would be to go full custom. it would be dear, but its also gonna be dear to source the complete s14 unit in AU.

the idea would be to pick up a set of quad throttles form http://www.efihardware.com. you would still need a custom adapter, and then a custom plenum to. i havent looked at pricing from the efi guys, but if you have any connections in the industry(read: mates rates), it would be another way to go. TRIKFAB(on here and other boards) is in Melbs, and machined up a custom plenum for his 318i Turbo project, so he could make a plenum, and possibly machine an adapter.

the other option to look at is using the ITBs off our s50. simply use 2 of the 3 pairs, and your in the same boat. i have heard rumours that this is a simpler mod than the s14 set up, but it will still need a custom plenum, and some MacGuyver like ingenuity.

its good to have someone local interested in this type of mod. :up:

looks like there could be a race between you, me and eric to get this done.

ive thought about this too rob, and i think it would have to be good for something. ive seen twin throttle conversions reap some nice rewards, and i see no reason why a quad system shouldnt help the m42 out. and if all else fails, and we waste a lot of money, at least its still gonna look tizzite when the hood gets lifted. :twisted:

[Streetspec_iS]

Since you be feeding more air in, you might want to re-adjust your AFM spring tension too and also tweak fuel a lil bit as is needed.

true, but i dont think id even consider this seriously without a MAF and piggyback at the least.

[e9nine]

Since you be feeding more air in, you might want to re-adjust your AFM spring tension too and also tweak fuel a lil bit as is needed.

true, but i dont think id even consider this seriously without a MAF and piggyback at the least.

I was thinking about this the other day. Boosted car's get away without piggy backs. A subtle mod like this @ lets guesstimate 80% efficiency should still be worthy considering the $$ saved. If you wanted the max. benefit of the setup, that's when u'd go with a MAF. If I were to do this I would hopefully do it in stages and start off with a base dyno. The annoying part is using a custom chip for the entire project after everything is said and done plus dyno time will make you :?

[Rob]

but look how much the S14 gains ditching the AFM, its plain ridiculous for that motor (althought the gains are similar to what the e36 guys get with bolts ons, doh!)


What I want to see (since i dont have the $$$ to do it) is you quacks building an m42 to make 160-170hp on the street, and spend less than the cost of a s14 motor.