8v weber downdraft build

[Snatcher]

Alright, so I thought it'll be great to post a build thread about this. I see a lot of people doing bike carbs and DCOE's. But I never seen a downdraft thread, there's always a first huh? (I know people have probably done this already, but I'm gonna post it anyway.) I'm going downdraft 'cause of lack of money to get dual sidedrafts. plus i fell in love with the throttle response after i drove my friend AE86 with a 3tc engine which has the same carb. it's 10 fold better than the throttle response i got from digi2.

Oh, and sorry in advance for mediocre cellphone pics :/

So far I've done the following.
1. Bought a weber downdraft kit for the 8v at BFI (not to mention other parts from BFI, really awesome people over the phone) It comes with everything from linkage, manifold, carb, filter, and nuts and studs. Everything needed besides fuel pump FPR, and throttle cable)




2. Got a redline fuel pump, a weber distributor 35GPH and 4-6psi (i have no idea what it means "4-6psi" maybe it changes with amperage at full throttle or something)



3. Holley FPR, 1inlet and 2outlets. pre-installed at 2.7psi. Good psi setting from what i've been reading around the forums. i bought the the inlets and plugs for about 2 bucks each




4. MSD blaster 2 coil.



5.MSD ignition 6al (just got it today, pretty cool looking box, and awesome from reviews i've seen on other applications

.


So I started to take off the intake, fuel rails and when i got to take off the intake manifold...
It is pure hell. So i decided, **** it. I'm going to take off the head and check if i have any bent valves (timing belt went to **** a while back, and i noticed a loss in power, but i probably did the timing wrong) It ended up being wrong my valves were fine. Just a **** load of carbon build up and just pure ass lol. Tip! If you have a single outlet manifold be ready to see sparks. Since I didn't have a wedge(bentley says to get a wedge to put inside the clamps to take them out) i got my breaker bar inside the clamp - closest to the battery and gave it a few yanks and PING **** sparked up and went straight to firewall and fell to the ground. firewall is fine, no cracks, chips, or dents. As for the other one toward the TB side. get on top of your fender and pull the head out at an angle in which the clamp will bend in and explode outwards and toward the floor like the other. Very unorthodox but it work and it's awesome to say "DO WORK SON!" with all that testosterone running. Lucky me I did it with a friend. Here's the outcome with the head and intake manifold of with some cleaning.

[Snatcher]

will post more soon!

[hastethemoment]

updates? Wanna do the SAME thing...87 kjet 8v(stock) to the BFI basic weber carb.

I wanna see all the wiring your able to remove , engine bay pics please?

Also just switching to this carb with decent tune I dont see why we cant get an extra few hp out of it? Esp with full exhaust/cam?

[Snatcher]

Taking out the wiring is a huge head ache. Power wise i have no idea. But now theres practically no restriction on fuel/air going into the engine. it's all dependent on the carb. There's no ECU getting in the way. I shall post pics in a bit of the progress i've made.

[Snatcher]

if you take out all the sensors and wiring that doesnt deal with the lights or main power (battery cable and such) you'll be left with a thin red and black wire that comes from the coil. i believe thats the positive and negative and when your key is on ON or ACC whatever it is, it sends signal to the coil. there should be two wires into a plastic piece, with the exact to wires coming out the opposite end, sorta like a crimp, to the wiring harness. and with that. bam de wired. there's other wires there too. i tucked them behind driver side strut side. i'll post where to wire the red wire to ignite the msd box once i get my grounds back grounded and a voltmeter!

[A1an]

Looking forward to an update with pics of the install, wiring, etc. Thinking about eventually doing this with my 8v.

Are you still running air conditioning?

[hastethemoment]

yeah ive already started pulling wires..all i Have on pass side is headlight and turn harness. My car is already been pulled of AC/ Power steering(lines looped). Just gotta keep the stock ignition, and all the dash sensors(oil pressure, temp, ect).

Having tough time of deciding doing this or going the R1 carb route....R1 carb will take alot longer to tune though(and making intake manifold) vs throw this in and go once the jetting is fine.

[Snatcher]

that's pretty sick dude, for me this is just going to be my daily until i get dual side drafts on a ABF build i'm doing. Aiming for a total rebuild of an engine, but since that takes time this is just to get my car back on the road but carb'd i'm going to be posting a helluva-lot pictures tomorrow once the sun is out!

[petergiarrizzo]

Just outta curiosity, I drive a 1996 Golf CL. Its a 1.8L 8V motor. (Canadian Model). It has the intake manifold facing the rear of the car, similar to yours, and its basically (from what ive made sense) run on a carburator (maybe even just a simple throttle body). would this kit work for it?

http://www.facebook.com/photo.php?pi...5&id=504038766

thats a picture of my engine bay. (dont laugh too hard) but tell me what you think

[hastethemoment]

yup. You are removing all the old intake/fuel system. So all that would go and be replaced with a new intake manifold, ect. You can also remove all the wires that connect to the intake, since they are no longer needed.

[Snatcher]

UPDATE! Unfortunately I have not been able to post up pictures. BUT! I will be getting a camera on payday, along with new fuel filter, my head being squeky clean, and ordering of new parts like (spark plug wires). And for letting you guys down. I'll step-by-step instructions of the whole install

[A1an]

Looking forward to it!

[B4S]

Just outta curiosity, I drive a 1996 Golf CL. Its a 1.8L 8V motor. (Canadian Model). It has the intake manifold facing the rear of the car, similar to yours, and its basically (from what ive made sense) run on a carburator (maybe even just a simple throttle body). would this kit work for it?

http://www.facebook.com/photo.php?pi...5&id=504038766

thats a picture of my engine bay. (dont laugh too hard) but tell me what you think

It won't fit. I've modified those intakes for single downdrafts...but it's not the best way. An adapter plate would be needed, custom made unfortunately. The bolt spread is different than any of the former VW-based carb systems out there.

You might want to re-think carbs though...it'll never pass emissions at a 1996 level with one on it. Unless you've got a VERY good, old-school carb tuner in your back pocket...who also owns an emissions shop, lol.

[Snatcher]

It won't fit. I've modified those intakes for single downdrafts...but it's not the best way. An adapter plate would be needed, custom made unfortunately. The bolt spread is different than any of the former VW-based carb systems out there.

You might want to re-think carbs though...it'll never pass emissions at a 1996 level with one on it. Unless you've got a VERY good, old-school carb tuner in your back pocket...who also owns an emissions shop, lol.

OR run your own emissions shop ;D

[petergiarrizzo]

Ha ha ha ha yeah i didnt think it would pass emissions. and the custom adapter plate would be....fun... to make but would it give some more horsies?

[B4S]

IMO, it would. The throttle bore of the CL 1.8 TBI is just about loonie or toonie sized. Add a second throttle opening in there and you'd probably add a few extra horses to the motor. The manifolds have a heat 'hedgehog' in them too, smooth that out and you'll flow a bit better, at the expense of some cold driveability .

I don't think you'd get more than 5-6hp, but I've owned a CL before...I know anything helps .

[Snatcher]

Hey guys, sorry about the delay.Had a busy weekend. But as I promised I got pics! The head is still off, I went to a machine shop and the dude said I needed new valve seals. So those are coming on the 8th and I have to wait till my next paycheck to get my head cleaned out so it's funky fresh and ready for the carb lol. Well for wiring. I unplugged the ECU and all the wires and connections that went to the wires.


So I got those guys out. I've been reading around and I've seen guys keep the ICM wired up to the distributor and ignition and have the MSD as well for it's power I guess. So I'm gonna try that out. I think it would work out.

Wiring Key: heavy red-battery terminal, heavy black- ground. orange:+on coil, black: (-)on coil. red to 12v switched to IGNITION (i got lucky, i think the PO tried to wire up a gauge or something)


So here is the bay after everything. I tucked some stuff behind the strut tower I don't remember where it was.

[doctor12valve]

Bump! Lets see more

[Snatcher]

Sorry about not updating! Haven't had the time. But today I do! I got some stuff in the mail.

8v silicone cooling kit i got from BFI, once again..cool people to work with.

and spark plug wires. from bfi...ditto lol.


I'm having a difficult time figuring out how my linkage and my carburetor works. but i think i figured it out. i'll post more pics tonight. Even though it's flipping freezing down here in miami it's 59*F cloudy and windy. Us miami-people are really not used to this >.<

[Snatcher]

Update! So what I did today was change the fuel filter. Apparently the PO didn't change it at all. T_T
NEW:

OLD:

Srsly d00d. Damn -.- P.S I highly recommend you work in a well ventilated area when doing this. If you're unlucky as me you'd probably get close to the filter to get leverage on the hoses that have not been touch since '92 and fuel will fall all over you and smell and become flammable.

I also got my exhaust manifold off the head. I had a stripped bolt, but I felt confident that I could take it out like a G. And I did.

Gonna clean it tomorrow once I get my valve spring compressor tool.
If you scroll up that's how it looked with SOME cleaning. Now this is it now. Unfortunately I ran out of degreaser

Can't wait to see how much better my car is going to run. Gonna post up the cleaning of the valvetrain tomorrow along with my linkage on the carb. Dudes at Redline Weber aren't much help with their "You could figure it out on your own from here on" T_T dickbutt.

[petergiarrizzo]

IMO, it would. The throttle bore of the CL 1.8 TBI is just about loonie or toonie sized. Add a second throttle opening in there and you'd probably add a few extra horses to the motor. The manifolds have a heat 'hedgehog' in them too, smooth that out and you'll flow a bit better, at the expense of some cold driveability .

I don't think you'd get more than 5-6hp, but I've owned a CL before...I know anything helps .

Yeah thats for sure, again thanks for the advice. any other tricks up your sleeve for a few extra horsies? im sure there arent many, but breaking the 100HP mark would be nice hahahaha

[B4S]

It's not feasible to break the 100 hp barrier on a CL, mainly because the management is VERY limited. You can do an intake, but are limited by the TB. Exhaust is easy to do, but is really just for sound IMO. Not being able to optimize the timing/fuel for a cam or a bit more intake flow is where the issue lies. The intake valves are also only 38mm, vs. the regular 8v's 40mm, and the cam is VERY mild. It's got almost 0* of overlap, so the ECU is basically designed for pure fuel efficiency.

A mild cam could wake it up a bit, and an exhaust will make it sound faster...but it's just not worth trying more than that, since the ECU is locked out .

[ps2375]

To the OP, how do you plan on getting the exhaust manifold clamps back on? Are you going to buy/make the tool or are you getting a header? Or are you switching to a dual outlet manifold and downpipe?

[Snatcher]

I'm going to clamp it back on, a friend of mine gave me the idea of jacking up the downpipe part of the manifold. Got a new gasket for it. should be pretty easy to get back on. Eventually I'd like to get a header or dual outlet manifold. But I'm going 16v/ABFclone once I get all the parts together

[ps2375]

I'm going to clamp it back on, a friend of mine gave me the idea of jacking up the downpipe part of the manifold. Got a new gasket for it. should be pretty easy to get back on. Eventually I'd like to get a header or dual outlet manifold. But I'm going 16v/ABFclone once I get all the parts together

[Snatcher]

Or do as the bentley says. Get that chisel and do it properly -.-

[haybayian]

Thanks for posting about your downdraft carb set up. As I am about to do something comparable I am glad to watch what you are doing. I am converting a 1998 ABA from EFI to carbs. My system will involve 4 downdraft webers 34 ICH. My hope is to use the stock VW manifold (lower end only) with a minor adapter. I do not have the carbs yet, so I cannot show pictures, but I will.

My question to you is about the MDS 6 al ignition module that you have bought. How are you going to use this? Could you describe your ignition system as you have planned it?

haybayian.

[Snatcher]

Thanks for posting about your downdraft carb set up. As I am about to do something comparable I am glad to watch what you are doing. I am converting a 1998 ABA from EFI to carbs. My system will involve 4 downdraft webers 34 ICH. My hope is to use the stock VW manifold (lower end only) with a minor adapter. I do not have the carbs yet, so I cannot show pictures, but I will.

My question to you is about the MDS 6 al ignition module that you have bought. How are you going to use this? Could you describe your ignition system as you have planned it?

haybayian.

Haha, no worries man. Carbs are a cool set up so I decided to share ze experience. Why don't you try doing dual 45DCOE's? 2 carbs are easier to tune than 4. The way I plan to run the msd is have it powered by the battery terminal (it's what the instructions say). Have the coil powered by it. And advance the distributor since Weber's like to run with advance timing (from what I've read on vwvortex/club4ag) So I'm going to have the msd power the coil. coil sends spark to distributor. The rest is self-explanatory. I've read people running the stock ICM. I'll probably do that too, having msd shooting it's multi-spark power

[xPat]

I feel i should warn you of a problem your might run into using that carb on your VW. I had done a similar setup on my cabriolet 2 years ago. I purchased a DGES 38 kit from Redline racing off eBay.

If your carb is anything like mine the main jets are at a 45 degree angle on the side of the float bowl. This carb is designed to be mounted with the main jets towards the firewall of the car. When mounted on our engines they will point to either the right or left wheel well. In this orientation you will experience either starvation or flooding while cornering.

I was told by Pierce Manifolds that only the Weber progressive downdraft carbs could be used on our engines, I switched to Megasquirt.

[Snatcher]

The one I got is a 32/36 DFAV it's a progressive downdraft carb. But thanks for the heads up. I don't want to take a sharp turn and my car shut off on me.

[B4S]

That bit of info is complete bunk IMO. The progressive carb has the exact same main jet configuration as the 38 DGES/DGAS, and nobody ever complains about fuel starvation. It's an OEM carb on a million different cars, still in use today in hundreds of countries. If your fuel pressure is set properly, the float height is correct, and your fuel delivery system is up to par, you'll experience no such issues.

The big issue with carbs (around here anyway), is that they're frequently installed and tuned from incorrect information (again, from here). A carb is far more difficult to tune than most people think it is, and most folks don't bother trying to get it right before they swap it off for a poorly-tuned EFI that they feel is 'better'.

[Mk1 Fish]

getting those exhaust clamps on is hell without the tool or some creative thinking. your friends idea of the jack will work to hold the down pipe in place but those clamps have a lot of tension, new ones will have more. take 2 old alternator belts, one for each clamp. place the upper hook of your clamp on the mani, get your belt on the lower hook, then find a big ass pry bar. prying down on the belt will get the clamp close, then have a buddy with another pry bar push the clamp over to the down pipe and release tension. you will have to cut the belts to get them off the car. hence, use 'old' belts. did this trick a few times then bought the tool...

[B4S]

I just invert an exhaust clamp and use it as a spreader.

[ABA Scirocco]

I just invert an exhaust clamp and use it as a spreader.

That method works great, almost as well as the special tools specifically designed for the purpose.

[Mk1 Fish]

I just invert an exhaust clamp and use it as a spreader.

very nice that pretty much is the tool, but free