# want to convert 8v Digi2 to single carb setup



## carolinaGTI (Dec 9, 2007)

so im looking into a single carb setup for my MKII GTi. the car has ported intake and exhaust ports, 270* cam, and Dual DP on it. will a 32/36 weber be enough carb? what all is involved in switching from Digi2 to carby? what will i need, remove, and replace? i assume an electric fuel pump (low psi), remove everything digi related, but what else? anyone done this swap b4? ive searched but didnt find much on the subject.


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## epjetta (Sep 19, 2006)

*Re: want to convert 8v Digi2 to single carb setup (carolinaGTI)*

switching to a MS would be a better idea. you dont even have to change any fuel stuff to convert.


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## carolinaGTI (Dec 9, 2007)

Im more of a mechanical tinker-er then a electronic's/wire tinker-er. I know MS and fuel injection will give better power and economy, but carbs are badass, east to work on, (i can tune by ear), and carbs sound great. i just need to know what all is involved in this swap. MSD? fuel pump?,set of jets? am i missing anything?


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## B4S (Apr 16, 2003)

*Re: (carolinaGTI)*

It always makes me laugh when someone posts up a desire to build a carbed car, and inevitably someone says "convert to standalone". I've been a die hard standalone user since 1999 (SDS, MS, Haltech, AEM EMS, to name a few), and I'm building an 8v on sidedrafts currently. I'm not even shooting for max power, I want to learn carbs. Sometimes, we build stuff that doesn't make sense to everyone, just to do it the way we want to http://****************.com/smile/emthup.gif. 
I'd imagine to switch to a 32/36 weber (which would probably be plenty of carb for your setup), you've pretty much named all the important stuff. The only other concern would be ignition. You could either swap to a vac/mech advance dizzy from a MkI and use the donor car's ICM and harness, or use the knock sensing ignition from an 85-87 MkII/16v rocco/etc. This would allow you to keep your digi distributor, as well as adding a knock sensor for that extra bit of safety on a hot day. The last option is an MSD 6A with the extra timing computer add-on, and the digifant distributor.


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## carolinaGTI (Dec 9, 2007)

i know where theres a rocco 16v, so thats an option, what about the MSD 6A? obviously the MSD will be the better system, but for the money is it really needed, or just "trick" and more tunable? what are some advantages and disadvantages to each option. BTW im a poor Mo Fo, so the 16v dizzy is probably more in my budget. lastly do you have pics of everything i'd need from the Rocco? i dont know jack about 16V's or rock0's


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## jetta-the-hut (Feb 10, 2007)

*Re: (B4S)*

hey B4S I'm helping carolinagti with this and had a few questions since I was always led to the MSD 6a side of the house


> The only other concern would be ignition. You could either swap to a vac/mech advance dizzy from a MkI and use the donor car's ICM and harness, or use the knock sensing ignition from an 85-87 MkII/16v rocco/etc. This would allow you to keep your digi distributor, as well as adding a knock sensor for that extra bit of safety on a hot day. The last option is an MSD 6A with the extra timing computer add-on, and the digifant distributor.
> 
> 
> > the digifant has a knock sensor ignition couldnt he just keep the system and run his ignition off the MSD?
> ...


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## carolinaGTI (Dec 9, 2007)

*Re: (jetta-the-hut)*

me too







...... also will any msd work? what type blaster coil do i need? single? dual? you mentioned an extra timing ad-on...is this an extra part? 


_Modified by carolinaGTI at 1:33 AM 5-29-2008_


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## B4S (Apr 16, 2003)

*Re: (jetta-the-hut)*


_Quote, originally posted by *jetta-the-hut* »_hey B4S I'm helping carolinagti with this and had a few questions since I was always led to the MSD 6a side of the house

_Quote »_The only other concern would be ignition. You could either swap to a vac/mech advance dizzy from a MkI and use the donor car's ICM and harness, or use the knock sensing ignition from an 85-87 MkII/16v rocco/etc. This would allow you to keep your digi distributor, as well as adding a knock sensor for that extra bit of safety on a hot day. The last option is an MSD 6A with the extra timing computer add-on, and the digifant distributor. 


the digifant has a knock sensor ignition couldnt he just keep the system and run his ignition off the MSD?
it sounds simple enough but I'm confused now?

_Modified by jetta-the-hut at 10:36 PM 5-28-2008_

I'm not sure the digifant ignition system can be run as a standalone, never seen it done before. I imagine if you left the ignition stuff hooked up and disconnected the fuel injection portion, you'd find out pretty fast. The main reason everyone goes for the CIS-E stuff is the simplicity, and the choice in ignition boxes (there are three of them, each with a different timing curve). The MSD is probably the best option, but is slightly more expensive than using old VW parts







.


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## carolinaGTI (Dec 9, 2007)

what parts will i need from MSD? heres some links of different parts on evil bay that caught my eye, and thought might be what i need. can you tell me which parts would be needed please?
(MSD 6T)
http://cgi.ebay.com/ebaymotors...sting
(MSD 5900 ignition)
http://cgi.ebay.com/ebaymotors...&rd=1
(MSD 2coil pack)
http://cgi.ebay.com/ebaymotors...&rd=1
(dual ignition adapter)
http://cgi.ebay.com/ebaymotors...&rd=1


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## B4S (Apr 16, 2003)

*Re: (carolinaGTI)*

-MSD 6A or 6AL...not sure what the T version does.
-MSD timing computer http://www.msdignition.com/tc_1.htm
or
-MSD adjustible timing computer http://www.msdignition.com/tc_3.htm
-stock coil is fine.


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## carolinaGTI (Dec 9, 2007)

well, i was looking at buying the MSD parts, until the cheapest compatible/ programmable computer was $150, not including the $100 or so on the ignition box, and $30 for the blaster coil http://****************.com/smile/emthdown.gif looks like its used OE parts for me. so just grab the entire igniton system off a 16v? distributer also? what parts do i need exactly? i know a junk yard i can possibly get everything from



_Modified by carolinaGTI at 4:21 PM 5-29-2008_


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## B4S (Apr 16, 2003)

*FV-QR*

You'll need the distributor (8v), knock box (should be in the rain tray), knock sensor (front of the block, by the oil filter housing), ICM (raintray again), Throttle body switches (or the whole throttle body), and the engine harness. Basically, once you find the ICM and Knock Box, take every bit of wire that runs into both of them. It's really not that much, just looks like a lot.


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## wilburisthecoolest (Jan 13, 2008)

I did the swap. Took a weekend at my buddies house taking it real slow.
I didnt change the fuel pump, just used a tee fitting before the FPR and sent the tee to the return back to tank. Works fine with just the junky autozone FPR. Used pennies under the stock plastic injector cups to seal those holes up. I had to buy a longer bolt for the throttle stop becuase the carb had a decreased pedal stroke for the gas pedal. and i replaced the fuel pump relay with the horn relay and omitted all ecu wiring and made my own harness.
completely stock engine with sdp, i made [email protected] rpm and 115ft [email protected] rpm.
Bout the only thing i did to the carb was to remove the choke and just use the high idle to help it start in the mornings. it seems to love that.

Oh did i mention that i get 43 mpg?


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## carolinaGTI (Dec 9, 2007)

how much power will i lose swapping to a carb or will I? the ICM is on top of the ECU right? could i grab these parts from a 16v Passat? lastly on average how much does all this stuff cost.. ballpark?










_Modified by carolinaGTI at 10:00 PM 5-29-2008_


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## B4S (Apr 16, 2003)

*FV-QR*

Yep, the ICM is on top of top of the ecu on certain models...and the 16v passat stuff is CIS-Motronic, not CIS-E. It won't work







.


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## carolinaGTI (Dec 9, 2007)

damn...thats ghey. idk where much 16v stuff is and the only parts car i know of is a 16v pussat 







do you have the parts i need or know anyone thats got them for cheap-ish


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## B4S (Apr 16, 2003)

*Re: (carolinaGTI)*

it doesn't have to be 16v stuff, the CIS-E system came in 85-87 GTI/GLIs, 8v and 16v roccos up to 87, etc. If you can find a VW of the years between 85-87, there is a good chance it will have what you are looking for. Any 16v golf/jetta/rocco prior to 1990 will have it too.


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## carolinaGTI (Dec 9, 2007)

theres a Golf that looks Digi under the hod ie. looks about the same as my 91, but is has less wires and mess. is this cis-e or digi 1? i instictivly know when i see the metal braided wires on the top of the air box, ive found a cis car. do the cis-e look the same or different? is the only way to know, is it check the date of manufacture on the door plate?


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## B4S (Apr 16, 2003)

*Re: (carolinaGTI)*

That airbox is a dead giveaway, all CIS-based cars had it. Those braided fuel lines are on every CIS car.


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## carolinaGTI (Dec 9, 2007)

okay we've been talking about alot of different parts, and ive made a checklist. 
1. my stock 91 8v distributer
2. knock box from 85-87 8v/16v golf or Jetta
3. knock sensor from 85-87 8v/16vgolf or Jetta models
4. ICM from 85-87 8v/16v golf or Jetta
5. engine harness from 85-87 8v/16v golf or Jetta
6. 8v MKI carby fuel pump
-------------------Substitute parts-----------------------
MSD 6A or T aka pn.6200 
MSD programmable ignition comp pn. 8980/8981
MSD Blaster 2 coil (stock will work also) 
Holly low psi electric fuel pump (any)


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## B4S (Apr 16, 2003)

*Re: (carolinaGTI)*

Yep, sounds about right. You can make two changes to your list of parts:
-ICM from any MkI or II, as long as it has 7 pins.
-block-mounted mechanical fuel pump (your car will have the proper lobe on the intermediate shaft, under a block-off plate by the oil filter standoff). It is a good choice for a progressive downdraft carb setup, and a bit cheaper than the other gear needed. You can use the mech pump from a carbed dodge omni 1.7 apparently, although I can't confirm this, never having done it.


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## carolinaGTI (Dec 9, 2007)

i got this setup. only paid $90 shipped!!!


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## CozySpeed (Sep 24, 2006)

*Re: (carolinaGTI)*


_Quote, originally posted by *carolinaGTI* »_i got this setup. only paid $90 shipped!!!

















have that same stuff siting at my house. wanted to just slam my 75 together with my 1.8l jh i got but now all that stuff is for sale.


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## carolinaGTI (Dec 9, 2007)

cool. im waiting to recieve the setup, from another member on here. cant wait. what manifold are you using?


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