# ITB vs FI



## rocklizzard91 (Dec 18, 2007)

Hello all, I've got a cam'd 9A 16V in my mk3 jetta and I'm looking for a nice project/power adder.
I'm not trying to make a bajillon horsepower. Just some more.
Contemplating Itb's and FI.
I like FI just cause I've always liked a nice turbo car. And its upgradeable.
I like Itb's cause it has the wow factor and sounds damn good








But neither of those are good reasons to pick one.
So I need to weight options.
I'm looking for good reliability. AT least good enough I'm able to daily it.
As for power I'm not terribly worried about a number to get to. 200 would be cool.
Budget is 2-3k which is pretty decent I would think.o
A tmw Itb setup is around 1500 ircc which leaves more for head work and other goodies.
And turbo setups can be built pretty well for not too much I hear.
Current specs are its a 9a running megasquirt.
Autotech sport cams 50mm intake manifold
All lw gears (cam int shaft flywheel)
Hd valve springs. 
Pcv blockoff with catch can
2.25" exhaust
What are the pro's and con's of each so I can make the best decision.


----------



## need_a_VR6 (May 19, 1999)

*FV-QR*

Depends on how many spare transmissions you have and now good you are at changing them.


----------



## rocklizzard91 (Dec 18, 2007)

*Re: FV-QR (need_a_VR6)*


_Quote, originally posted by *need_a_VR6* »_Depends on how many spare transmissions you have and now good you are at changing them.








have one spare just needs a 5th gear
and ive gotten quite good at swapping them. just did one two days ago to do a clutch job. took a couple hours.


----------



## Rocco R16V (Oct 7, 2008)

*Re: ITB vs FI (rocklizzard91)*

what is more important to you, throttle response or big power?


----------



## rocklizzard91 (Dec 18, 2007)

*Re: ITB vs FI (Rocco R16V)*


_Quote, originally posted by *Rocco R16V* »_what is more important to you, throttle response or big power?

Either is fine. I like back road/mountain driving. So throttle?
How reliable are Itb's? I heard part throttle sucks on them. THey are like on off switches


----------



## need_a_VR6 (May 19, 1999)

*FV-QR*

They are more like on/off switches, but it gets worse as they get bigger. A 40-42mm throttle set on a 2L motor isn't that twitchy.
There's a totally different feel between the two, and obviously for the same amount of dollars the turbo will get you more power.


----------



## rocklizzard91 (Dec 18, 2007)

*Re: FV-QR (need_a_VR6)*


_Quote, originally posted by *need_a_VR6* »_They are more like on/off switches, but it gets worse as they get bigger. A 40-42mm throttle set on a 2L motor isn't that twitchy.
There's a totally different feel between the two, and obviously for the same amount of dollars the turbo will get you more power.

hmmm that doesnt sound like fun in traffic








im more concerned about driveability vs power though
how bad is the on/off feeling?
in that other thread i said i found those TB's and i believe they are 50mm tapered down to 46mm
that too big for good daily driveability?


_Modified by rocklizzard91 at 7:10 AM 4-21-2010_


----------



## need_a_VR6 (May 19, 1999)

*FV-QR*

46's will be a bit twitchy, but you'd get used to it. I wouldn't want to use them in a lot of stop and go traffic.


----------



## rocklizzard91 (Dec 18, 2007)

*Re: FV-QR (need_a_VR6)*


_Quote, originally posted by *need_a_VR6* »_46's will be a bit twitchy, but you'd get used to it. I wouldn't want to use them in a lot of stop and go traffic. 

i dont have a lot of traffic.
some yes
can you try to better explain what you and others mean by on/off switching and twitchy?
ive got a 4puck clutch in my 16v now (temporary clutch til a new one arrives)
and i would say it is like an on/off switch because the window of slippage is very narrow and is easily passed so its either grabbing or not grabbing.
are itb's either reving to 7k or idling?


----------



## need_a_VR6 (May 19, 1999)

*FV-QR*

It's like that but with the gas pedal.


----------



## rocklizzard91 (Dec 18, 2007)

*Re: FV-QR (need_a_VR6)*

Hmmm how do people drive on them then? Like driving through a neighbourhood at 25 with like ten percent throttle. That not possible with Itb's?


----------



## need_a_VR6 (May 19, 1999)

*Re: FV-QR (rocklizzard91)*

Takes some practice just like it did with the clutch.


----------



## rocklizzard91 (Dec 18, 2007)

*Re: FV-QR (need_a_VR6)*

Hmmm ok


----------



## Jetta_Coupe4Life_81 (Feb 3, 2008)

*Re: FV-QR (rocklizzard91)*

yea man ive never had to much drivability issues with my itb's. its just all in dialing in the maps good. i can hold an off idle crawl and go up hills just off idle in low gear. its just getting used to it and most importantly getting your timing maps right! i found that alot of my hesitation was just that it wanted a little more timing in the low end of life.


----------



## rocklizzard91 (Dec 18, 2007)

*Re: FV-QR (Jetta_Coupe4Life_81)*


_Quote, originally posted by *Jetta_Coupe4Life_81* »_yea man ive never had to much drivability issues with my itb's. its just all in dialing in the maps good. i can hold an off idle crawl and go up hills just off idle in low gear. its just getting used to it and most importantly getting your timing maps right! i found that alot of my hesitation was just that it wanted a little more timing in the low end of life. 

That's very good to hear http://****************.com/smile/emthup.gif what size and kind of orbs do ya have?


----------



## WolfGTI (Jun 16, 1999)

*Re: ITB vs FI (rocklizzard91)*

I had 45mm's on mt 2.0L 8v and I have 48mm's on the 2.0L 20v.
Honestly the hardest part was tuning them in. need_a_vr6 was very helpful in tuning the car. He spent many hours in the passenger seat helping me dial in the accel enrich and timing. I drove my car for over 2 years all year round and I basically data logged for months and tweaked the maps to get it very driveable. I could move along at 5mph in traffic no problem. 
It really comes down to how much time you are willing to invest in tuning.


----------



## ValveCoverGasket (Mar 20, 2002)

*Re: ITB vs FI (WolfGTI)*

id lean to the ITBs personally... i think with the turbo at that budget you'd end up wanting more pretty quickly. and the costs could snowball out of control.
ITBs would leave you the option to do some cheaper NA power adders down the road later, but still wake the car up on your current budget


----------



## Jetta_Coupe4Life_81 (Feb 3, 2008)

*Re: FV-QR (rocklizzard91)*

i think they were 34 or 36 tyeat tapered down some. in a stock 1.8 jh


----------



## rocklizzard91 (Dec 18, 2007)

*Re: ITB vs FI (WolfGTI)*

ok good positive posting on them now







giving me some hope








the ones im looking at are 45 or 46 iirc (98 gsxr 750 itb's)
gonna tell the guy i want them today








i have a guy who can make me a nice custom manifold, fuel rail and vacuum log. (or whatever else i want/need) my whole setup minus tuning will be about 500-600 if i dont need injectors. http://****************.com/smile/emthup.gif im not sure if i want to run the injectors i have no in the bottom of the stock manifold, or run bike injectors so it looks pretty.
as for tuning gotta pay to play, just like with my current setup. i can justify tuning. the manifold guy also tunes, and has tuned me twice before and im happy with his tuning. also im learning as i go so i can do a little dialing here and there
i agree with you valvecover
itb's will give me some fun at first.
then i can move to a PnP head. bigger cams. bigger valves. higher comp. whenever i crave more power. it seems like a good route to me








thanks all for your help








getting excited!


----------



## need_a_VR6 (May 19, 1999)

*FV-QR*

GSXR's aren't that big I think they're 42 taper to 40's or straight 42's depending on the year.


----------



## rocklizzard91 (Dec 18, 2007)

*Re: FV-QR (need_a_VR6)*

The carb directory thread for 99 gsxr said they were big


----------



## Rocco R16V (Oct 7, 2008)

*Re: FV-QR (rocklizzard91)*

I would also lean toward an ITB setup. the dual webber 40 DCOE's I had on a ford 2L was awesome. if your concerned about drivability look for something in the 40mm range. the 45's will be more on/off, and the 40's flow plenty.


----------



## need_a_VR6 (May 19, 1999)

*FV-QR*

The only GSXR's with bigger throttles are Hyabusa ones.


----------



## rocklizzard91 (Dec 18, 2007)

*Re: FV-QR (need_a_VR6)*

Right on. We'll see when I get them I guess


----------



## rocklizzard91 (Dec 18, 2007)

*Re: FV-QR (rocklizzard91)*

next question!
you guys are very helpful so i might as well just keep it going in here








should i run bike injectors in the ITB's and have a custom manifold to bolt the ITB's to made? (quoted 300 for manifold)
OR
get a lower 16v manifold to hack up and use my current injectors down in the 16v manifold and plug the ITB injector holes?
or maybe even get the ITB injector holes bored out to accept my current injectors?


----------



## need_a_VR6 (May 19, 1999)

*FV-QR*

I used the GSXR injector ports for a vacuum log and used a stock 16v lower and stock type injectors.


----------



## rocklizzard91 (Dec 18, 2007)

*Re: FV-QR (need_a_VR6)*

good results with that setup?


----------



## Prof315 (Jan 5, 2009)

*Re: FV-QR (need_a_VR6)*

We have GSXR ITBs on the GTL car now (leaving to race it in a couple of hours) We use a Weber DCOE manifold with an adapter plate to hook up the ITBs. (1/8" steel plate with 1 1/2" long tubes 1 3/4" diameter welded to it.) The injectors are in the head (8V eurospec) and the ITB injector bungs are used for IAC. It starts up easy and purrs like a kitten. Way better than when we had a Eurospec ported Mk1 plenum manifold on the car. 


_Modified by Prof315 at 6:58 AM 4-23-2010_


----------



## rocklizzard91 (Dec 18, 2007)

*Re: FV-QR (Prof315)*


_Quote, originally posted by *Prof315* »_We have GSXR ITBs on the GTL car now (leaving to race it in a couple of hours) We use a Weber DCOE manifold with an adapter plate to hook up the ITBs. (1/8" steel plate with 1 1/2" long tubes 1 3/4" diameter welded to it.) The injectors are in the head (8V eurospec) and the ITB injector bungs are used for IAC. It starts up easy and purrs like a kitten. Way better than when we had a Eurospec ported Mk1 plenum manifold on the car. 

_Modified by Prof315 at 6:58 AM 4-23-2010_

Awesome! Do you have any pic's of your setup?


----------



## need_a_VR6 (May 19, 1999)

*FV-QR*


_Quote, originally posted by *rocklizzard91* »_good results with that setup?


It ran well, got a good street tune on it, owner sold it, new guy blew it up and parted it out. So yeah, good results.


----------



## rocklizzard91 (Dec 18, 2007)

*Re: FV-QR (need_a_VR6)*


_Quote, originally posted by *need_a_VR6* »_
It ran well, got a good street tune on it, owner sold it, new guy blew it up and parted it out. So yeah, good results.








nice Haha


----------



## Rocco R16V (Oct 7, 2008)

*Re: FV-QR (rocklizzard91)*


_Quote, originally posted by *rocklizzard91* »_next question!
you guys are very helpful so i might as well just keep it going in here








should i run bike injectors in the ITB's and have a custom manifold to bolt the ITB's to made? (quoted 300 for manifold)
OR
get a lower 16v manifold to hack up and use my current injectors down in the 16v manifold and plug the ITB injector holes?
or maybe even get the ITB injector holes bored out to accept my current injectors?

In theory; injectors closer to the head helps idle and emissions, Injectors far from the head help atomization at high RPM. I doubt that you would notice a difference with either set up.
So the answer is all of those options would probably work equally well. The 16v lower manifold sounds like the easiest option but pay attention to where they were cut as to not make an edge that would create turbulence.
I think I would look into having a custom flange welded onto the 16v lower intake, so I could bolt on the itb’s.


----------



## rocklizzard91 (Dec 18, 2007)

*Re: FV-QR (Rocco R16V)*

Awesome. And how do I not cut to create turbulence?
Also since there are no flanges on the back side how would I have a manifold made to bolt them to? Thought the only way to mount was weld or couplers


----------



## ps2375 (Aug 13, 2003)

*Re: FV-QR (rocklizzard91)*

Here's pic of a custom manifold I bought off of the vortex for our ITB setup, was gonna use couplers but decided to have a local muffler shop open the tubes just enough to inset the ITB's into and then I secured them w/ set screws and sealed with Dirko sealant. They are GSXR 750ITB's, also bought on the vortex. We are waiting on a clutch disc at this time before we can start on the motor install into the car.







These pics are the mock-up on the spare head and w/ the 1.8t fuel rail we will use. And we have some foam sock filters to go over the stacks.


----------



## Rocco R16V (Oct 7, 2008)

*Re: FV-QR (rocklizzard91)*


_Quote, originally posted by *rocklizzard91* »_Awesome. And how do I not cut to create turbulence?
Also since there are no flanges on the back side how would I have a manifold made to bolt them to? Thought the only way to mount was weld or couplers

after cutting, round inner edge so its not sharp.
sorry my ignorance of gsxr tbs got me there. was thinking in general ITB's terms. I guess with those I would probably just use silicone couplers, if welding them directly on to the manifold didnt look doable.


----------



## Prof315 (Jan 5, 2009)

*Re: FV-QR (rocklizzard91)*

I'll take a couple and IM you for email.


----------



## rocklizzard91 (Dec 18, 2007)

*Re: FV-QR (Prof315)*

AWesome http://****************.com/smile/emthup.gif


----------



## -RalleyTuned- (Nov 17, 2008)

*Re: FV-QR (rocklizzard91)*

i have an ITB manifold my friend had made and we ended up not using it. $100 and it's yours. Its basically the same as the one posted except its not polished


----------



## cosmo50cc (Aug 12, 2005)

*Re: FV-QR (-RalleyTuned-)*

hey sorry ill send pic out soon


----------



## ps2375 (Aug 13, 2003)

*Re: FV-QR (-RalleyTuned-)*

Thanks for thinking they are polished, but they aren't. Just a machined flange and some tubing, I can't recall the name of the company he said it was made by, but it is some quality work. I thought I had their site bookmarked, but I can't seem to find it.


----------



## -RalleyTuned- (Nov 17, 2008)

*Re: FV-QR (ps2375)*

sorry shiney, not polished


----------



## ps2375 (Aug 13, 2003)

*Re: FV-QR (-RalleyTuned-)*








, I hope they perform as well as they look. http://****************.com/smile/emthup.gif







They only downside is I bought green sock filters w/o even thinking I could get them in a diff color from the local supplier.


----------



## rocklizzard91 (Dec 18, 2007)

*Re: FV-QR (ps2375)*


_Quote, originally posted by *ps2375* »_







, I hope they perform as well as they look. http://****************.com/smile/emthup.gif







They only downside is I bought green sock filters w/o even thinking I could get them in a diff color from the local supplier.









whered ya get em?
wouldnt mind green sock filters


----------



## ps2375 (Aug 13, 2003)

*Re: FV-QR (rocklizzard91)*

I got them at a local place that is a motorcycle "salvage" place. They are a UNI filter, and the color is a pale green or "puke green", not the best match for the Mars Red of an 1980 Scirocco engine compartment.


----------



## rocklizzard91 (Dec 18, 2007)

*Re: FV-QR (ps2375)*

Oh







I thought it'd be like a cool Green


----------

