my crazy idea? Bike ITBs + Megasquirt

[Warwick5s]

well....i've got a few ka24e's and a tranny sitting in my garage, and will be rebuilding one over the winter to go in my car in the spring. now, i was a vw 16v guy for a long time before getting my 240, and they do everything from supercharging, turbocharging, ITB's, carbs....whatever, but the thing is that there's lots of experimenting because they're cheapasses. (they're even more ghetto/cheap than S13 owners!) and one thing that lots of them do is to get a set of motorcycle individual throttle bodies, like this:



i had 40dcoe weber carbs on a 2.0 vw 16v engine, and was overcarbed. so i think something with around a 40mm throat on a 2.4 litre engine that won't rev as high should work out nice.

and for fuel i'll use a megasquirt ecu ( http://www.bgsoflex.com/megasquirt.html ) to control fuel, with the stock ECU controlling ignition and everything else. the cool thing about this setup is that i can get a set of ITB's with injectors and sensors for under 200 bucks, and the megasquirt you build yourself from a kit, and it costs around $150 and is VERY powerful. it uses a throttle position sensor and a manifold pressure sensor to determine fuel mapping so it would work fantasticly with ITB's.

i know i'd be able to get the megasquirt put together and working right (and if not, my dad the engineer would be able to fix whatever i did . ) so i guess my only concern is mating the throttle bodies to the head, which will require some planning.

so i guess what i'm asking is if there's something i'm overlooking, or if i am in fact crazy for trying this. i'm not sure if i'll be able to keep AC (although it doesn't work so i guess i wouldn't miss it, but it'd be damn nice to have), if there would be an easy way to mount the carbs i'm not thinking of, or any helpful comments.

and if anyone is confused still, check this thread at vwvortex: http://forums.vwvortex.com/zerothread?id=914763 , this is exactly what i plan on doing.

[deviousKA]

Im doing the same thing using megasquirt. If i could ask you a question though, what bike? do those throttle bodies come off of? 4cyl? or did you link them all together there in your pic. I am using different ITB's and am custom fabbing my own manifold (done). That itb setup above looks like something i would buy in the future, if affordable

ps. you have taste, and i also like the way your going about it.

[Warwick5s]

i'm planning on using suzuki GSX-R throttle bodies. they're easy to get, cheap, and real nice. the 600 and 1000 have 42mm throats and the 750 and 1300 (hayabusa) have 45mm throats. only snag i can see right now is fueling, but they make bigger injectors for all of them, or supposedly honda 959 injectors flow much more fuel and drop in with a minor alteration.

edit: i just remembered another snag - the lack of a fuel return line on the GSX-R fuel rail. not sure how to fix that one yet....


we're talking 100-200 bucks for the assembly, including injectors. that picture is from an ebay auction that went for 70 bucks!!!! it's too cheap to not do it this way.

[Ghettokracker71]

I love those ideas!!!!!!!!!!!!!! Trust me dude,you think VW guys,and S13 guys are cheap-o's? Go hang out with some of those MG/Triumph guys...I used to tune a bunch for a freind,and at the time I owned a Chevelle,.....Thats a mega bad-ass idea you got going there,good luck with it,I might just have to copy-cat your ass once you firgure it all out!....hah ha,I wouldn't do that,thats crappy man,no originality,I'd just be jealous b/c I didn't think of it...

[mbmbmb23]

Or you could buy this (its expensive tho)


http://www.tweakit.net/throttle_body..._throttles.htm

http://www.tweakit.net/throttle_body..._throttles.htm






-m

[SR240DET]

Warwick5s can you elaborate the megasquirt for me? iv read it some... but how do you plan on tuning it? im thinking about doing this for my s14 if i can figure out the megasquirt..

[Warwick5s]

Originally posted by SR240DET
Warwick5s can you elaborate the megasquirt for me? iv read it some... but how do you plan on tuning it? im thinking about doing this for my s14 if i can figure out the megasquirt..

i am of course by no means an expert on this, but i think this is how it works:


the megasquirt is a fuel controller (doesn't control ignition). in it's most basic form it looks like it needs inputs from o2, manifold pressure/vaccuum, tach signal, coolant temp, throttle position sensor, and intake air temp, which is a pretty nice setup when you're thinking about going ITB's. a MAF based unit would suck dick on an ITB setup, and due to the small amount of things needed i should be able to leave the stock harness in and just unplug what i don't need, and if i ever wanted to revert back to stock it would be EASY.

the REALLY cool part about the megasquirt is that it, much like any other standalone fuel system, it's totally laptop tunable with a program the creators wrote. you plug in things like injector flow, engine size, cylinder layout, etc and it generates a base fuel map, and then you can tweak it until it's perfect - which may or may not require some dyno time.


on another note about this project, whilst taking a crap last night i managed to draw up how i want the adapter to be, and i think it will work with no problems. ITB's will be attached to the adapter the same way they would be on the bike - through clamped boots. but instead of using the suzuki style ones that clamp on a flange on both sides i'm going to try to find similar sized yamaha ones because they bolt, not clamp onto the head. this means that i can make the adapter one piece if i need to because i don't need to add flanges to anything, instead i will just tap a hole for the boots to bolt to.

i also discovered www.emachineshop.com, which should, if nothing else, be able to give me a quick estimate at how much i'm looking at to get this thing made, and i'll probably have my dad do the final plans in his real CAD program.


other random thought: if i can get this thing working in a pretty repeatable fashion, would this adapter something people would be willing to buy?

[deviousKA]

Megasquirt is an awesome setup. You have to know a thing or two when it comes to circutry and how to read schematics but that is really simple stuff. If you build it yourself you can walk away with a full wallet.

Those bike itb's are a good idea, but do to the modifications necessary (mainly the injector hassle) you may want to look around for better option. The 42mm size is also a bit small. I am using a modified stanza intake with oem injector bosses and fuel rail. I am using 55mm throttle bodies with standard straight filters. My setup is not for the faint of heart and is going on my wicked high rpm 2.3l ka sohc. A throttle body size of 45-50mm imho would be better suited for ka and its flow patterns under 7000rpm.

You can find various throttle plate assemblies for very good prices. It is much more simple to use oem manifold and injector bosses to start.

I want to see more of these running around

[SR240DET]

very nice... =) im not sure i would trust my self with the megasquirt just as long as i wont blow my engine tuning it.. i could figure it out.. =)

Warwick5s id be interested in the adapter if all goes well.. please keep this threat alive.. im really interested in this ITB project..

[Warwick5s]

hmm...devious you really think i'd be undersized? in that case, perhaps hayabusa TB's will solve both of my problems. they're 46mm, flow 270cc/min (a smidgeon low - i'd like to have around 350cc/min because that's what a stock SR pushes), AND they use a fuel system with a return line, AND have an external fuel pump/regulator which i might be able to use as well.

could work...i'm more concerned with having something that's daily driveable than something with monster hp, so i don't want to go TOO big.


edit: jesus, i wish i did this much research in school. apparently with a 10mm spacer, denso green injectors from a toyota 7mge (part nos 23250 70080 and OE80) share all other seals and harness connectors with the gsxr injectors and flow 315cc/min...hmmm...


super edit: damn. it's 3am and i'm still pouring through megasquirts website. found a killer injector calculator dealie http://members.shaw.ca/megasquirt/manual/minj.htm#size , and it looks like i shoudl have between 305-389cc/min to have between 200-250hp. that's REAL high for what my plans are on this motor, but i suppose i could run the stock injectors (which according to that same site, 270cc/min should be good for around 180 hp, which is around where i plan on being to start....)

[Nismopu]

If you can stand it, there is an excellent article on CarCraft the magazines website. Unsure of the address but I am sure if you use google it should point you in the right direction. I have been a close follower of Megasquirts development and now with the addition of being able to control ignition you just cant beat the price! I hear from quite a few people who use this system that it is a an absolute pain to program the igntion and soon there will be a revision in software that will be more user friendly. Also when that happens you still wont have to buy a new system and instead you just load the new software.

Good Luck!

[SR240DET]

what about this http://www.tweakit.net/haltech/web_haltech_e6x_sr20.htm insted of megasquirt?

edit:never mind 1,145

[Nismopu]

Haltech many thousand dollars! Me like the price of $225 instead of that outragous amount, plus you can adapt the multi coil pack ignition from GM cars and have the boys at megasquirt help you program it. Makes more sense to go with megasquirt, sorry.