to itb or not to itb

[furryrabbit84]

ok...so i have been thinking about itb's.....on a 2.slow bigger to 2.1-2.2. thinking about robbing them from a bike unless there is a better...CHEAP....way to get hold of a set of 4. any imput would be helpfull. also heard mega squirt was not so helpfull on the itb front....any word?

[ShowCar]

Kris will chime in here, I'm sure.

[Digital K]

do not do bike itb's. I repeat... do not do bike itb's. Megasquirt has nothing to do with it...

[John2.0T]

If you do it cheap... you will regret it.

if your going to build up your engine - slap a turbo on it.

[Digital K]

or buy badger 5's or something

[flippinvw]

Well, the crossflow ain't that bad of a motor but that's not what I would start out with if I wanted a high-flow, high-rpm ITB motor. I've heard of a lot of people getting great numbers running the 1.8T motor NA. Of course the 16v is always a popular choice as well.

[EWAustin]

The problem with ITBs and Megasquirt is that MS batch fires the injectors. Because of the inlet tract pressure differences between when the valve is open and when the valve is closed, if the injection isn't timed to valve events rather than crank events you can have fuel flow differences up to 15% between the cylinders. Resulting in some rich cylinders and some lean cylinders. At WOT the difference is less, but it's still there.
(I learned this from a guy who designs snowmobile EFI systems for a living, so I believe him)

So, (Thure), if you want to run ITBs on your crossflow 8v, you'll need to either find a way to install a cam position sensor, or wire up the hall-sensor on the distributor to the aftermarket ECU so it knows where the cam is.

As for the ITB hardware, I've been looking at the USRallyTeam units.
http://usrallyteam.com/itb.html

Now another question (for everyone one there). Does a 20v head have a cam position sensor?

(P.S. on a pro-vintage note, CIS is IDEAL for ITB use...)

[Digital K]

i would have to disagree on the ideal for ITB's use. the throttle plate is a major restriction. that said I might try it anyways.

[EWAustin]

erm yeah, forgot about that detail...

I was referring to the constant spray of fuel being Ideal. Whereas EFI is pulsed injection.

[Digital K]

I suppose CIS and ITB's would be the closest you ever could get to carbs and fuel injection together.

[furryrabbit84]

so how about the possibility of using bmw itbs and an ecu designed for an e30 m3....is that even a workable idea. i understand that a custom mounting plate would be nessisary but i had come to terms with that already. i had planed on a $3000 budget for the motor i/e itbs head and engine management but at that it might be cheeper to just find a 20v turbo. plus turbos suck...pun intended, and everybodys dogs mom has a turbo and i like 8vs.:confused:

[Digital K]

dunno bud. good luck though. you'd get better power out of a 16v w/ a cam set easy

[momo]

or buy badger 5's or something umm may i ask what are badger 5s?:O_o:

[Digital K]

http://www.badger-5.com/2001/images/complete-tbodies-small.jpghttp://www.badger-5.com/2001/images/photos/badger5-dth-tbody-240x180.jpg

[momo]

ok thanx

[veedubthuggin]

whoa another momo?

[furryrabbit84]

the power issue is really almost an afterthought. what would really make me happy is the almost ferrari like sound comming from under the hood of my ginster. also i would like the option of easily switching back to a nearly stock setup by reattaching the intake manafold and original ecu. that way heven forbid i actually have to smog this thing while i'm in cali i could without to much trouble. plus i don't like extra valves just hanging around my head. vw has long since proved you only need 8:D

[momo]

what do u mean another momo?

[Digital K]

the power issue is really almost an afterthought. what would really make me happy is the almost ferrari like sound comming from under the hood of my ginster. also i would like the option of easily switching back to a nearly stock setup by reattaching the intake manafold and original ecu. that way heven forbid i actually have to smog this thing while i'm in cali i could without to much trouble. plus i don't like extra valves just hanging around my head. vw has long since proved you only need 8:D

haha whatever floats your boat. won't sound like a ferrari. :P I never understood the 8v crowd. They just are sub par. Such a money toilet unless you are putting a big turbo on them, and even so, a 16v takes it better.

[Die Frau]

ITB?

in the butt?

[EWAustin]

Just about...

It stands for Individual Throttle Bodies. Think like carbs for EFI...

[Die Frau]

yeah I know, jus' playin'

[EWAustin]

yeah me too, I seemed to have omitted the requisite smilies though...

[furryrabbit84]

you know the smiles are a delicous and nutrisious part of a ballenced post:D

[EWAustin]

you know the smiles are a delicous and nutrisious part of a ballenced post:D

Says the man who just learned that you can talk to people over teh intarw3bs...

[jedi knite 2.0t]

too much $ per HP very minimal gains unless you have a built block and a really flowed head then your almost better off with a nice set of sidedrafts and cams then itb IMO :thumbup:

3k is a 1.8t swap in my eyes :drool:

[Digital K]

side drafts arent going to be any better than ITB's on a stock motor. fuel atomization might be a bit better, but without the airflow to back it up it wont matter.

[EWAustin]

side drafts arent going to be any better than ITB's on a stock motor. fuel atomization might be a bit better, but without the airflow to back it up it wont matter.

I highly doubt that even the fuel atomization will be better. Because ITBs and Sidedraft carbs have such a short intake tract, the intake velocity slows greatly when the valve is closed. Less velocity means poorer atomization if you're running a carb.

Also, because of how fast the engine spins, the injector can't spray only when the valve is open and deliver enough fuel to keep the engine from eating itself alive. As a result, a lot of the fuel is sprayed onto the back side of the intake valve, where it vaporizes. Show me a carb that boils the fuel for you and I'll show you a car that won't run. :P

[momo]

how much more power will itbs or cams give you normally?

[Digital K]

itb's by themselves arent going to give you much power.

[furryrabbit84]

all of these things need to work together. i have a 276 cam and titanium valve springs/ retainers. my motor spins nicely but itbs would allow me to suck more air/fuel than the single throttle body getting me more from my cam maybe letting me run bigger like a 308 cam:thumbup:

[Digital K]

why doesnt anyone listen to me?

[StickiestOfTheIckiest]

too much $ per HP very minimal gains unless you have a built block and a really flowed head then your almost better off with a nice set of sidedrafts and cams then itb IMO :thumbup:

3k is a 1.8t swap in my eyes :drool:

Good luck doin a 1.8T swap for 3k. I searched for 1.8T swaps when i had my red MKIII and i couldnt even find a motor for that price....well, there was a Passat one on eBay for 1500, but it needed a FULL rebuild....

[tobin999]

Good luck doin a 1.8T swap for 3k. I searched for 1.8T swaps when i had my red MKIII and i couldnt even find a motor for that price....well, there was a Passat one on eBay for 1500, but it needed a FULL rebuild....

http://minneapolis.craigslist.org/pts/517590645.html

turbo mani, turbo, oil pumpm, and oil pan. Looks like a good starting place

[flippinvw]

undergroundvwparts or whatever on the tex has pretty good deals on 1.8T swaps

[Midw3st_dubn]

16vT

[StickiestOfTheIckiest]

damnit, where the hell where these when i had the last car :mad:

i agree on the 16vt though :thumbup:

[Midw3st_dubn]

you can pull of outrageous numbers on a 16vT.

[furryrabbit84]

not a bad idea that! a 16v head will fit without any mods but i like 8vs there is something wrong with me. i think i want to build this motor and find a car to put it in later. i have cought the mk1/2 bug again. but i do think that is a valid idea.

[flippinvw]

just run nitrous through it til it blows up, hopefully by then you'll have come to your senses and will build a motor worth the investment :P

[furryrabbit84]

thats not very nice a$$ hat. JK. i think the aba 16/20v is the way i'm leaning on this....maybe w/ a blower instead of turbo. i like blowers they sound neat like "grrrgle can i make you a sandwich" :thumbup: . out here in cali i have run across a couple of nicely wrecked gti/golf/jettas that are 1.8t/manual and $3000-$4500. thank you crappy la drivers! anyone know the hassle factor of 20v head on an aba? i like the idea of an extra 12 i don't need. go big or go home right? thats enough for a whole vr:D

[EWAustin]

...anyone know the hassle factor of 20v head on an aba? ...

I'm already reading this: http://forums.vwvortex.com/zerothread?id=1674618

[Digital K]

I wouldnt build a hybrid on your first swap venture.

[flippinvw]

Yeah, why even bother? You can make just about any amount of horsepower with the 1.8T and there's torque aplenty if you leave it as-is and don't strap on a huge exhaust and start porting out/changing cams and such. Perfectly fine in a lightwieght car (ask Chad!).

[furryrabbit84]

the stock 1.8t is looking better and better after every page of that i have read. i would like to have some relyability in the future of my car so i can actually drive the thing. i am definately thinking mildly modded 1.8t and thats it. all the swapping arts and sourcing crap from here and there makes my head spin. i had enough trouble getting parts for my rabbit and that was just a 1.8 8v europian motor screw all the messing about.

[KOOTER]

The problem with ITBs and Megasquirt is that MS batch fires the injectors. Because of the inlet tract pressure differences between when the valve is open and when the valve is closed, if the injection isn't timed to valve events rather than crank events you can have fuel flow differences up to 15% between the cylinders. Resulting in some rich cylinders and some lean cylinders. At WOT the difference is less, but it's still there.
(I learned this from a guy who designs snowmobile EFI systems for a living, so I believe him)

So, (Thure), if you want to run ITBs on your crossflow 8v, you'll need to either find a way to install a cam position sensor, or wire up the hall-sensor on the distributor to the aftermarket ECU so it knows where the cam is.

As for the ITB hardware, I've been looking at the USRallyTeam units.
http://usrallyteam.com/itb.html

Now another question (for everyone one there). Does a 20v head have a cam position sensor?

(P.S. on a pro-vintage note, CIS is IDEAL for ITB use...)

Your theory is good but not really accurate unless your running N/A with 96# injectors or something waaaay out there like that.If you batch fire the injectors you can do just fine.

That said the newer megasquirts run sequential injection anyways.

The cam position sensor on a 2l 8v is the distributor.If you have a 16v you can probably use a motronic plug wire set with the cam sensor on the wire.

I am actually looking at the new megasquirt to run all sensor info through the OBD port.These units are probably the most high tech ecus available and can read CAN/BUS off the stock ecu.