The all carb diet.

[the12for12]

Quote, originally posted by VenaGTi »

wow. cool set-up. does it fit under the hood?

yessir.

[impulse byer]

[B4S]

Nice! Is it yours?

[impulse byer]

http://www.youtube.com/watch?v=3m2WzBQlrUs

No it's not mine but i'm putting one together for my other car but i'm might test it on my rocco....no i will test it on the rocco.

The other car is air cooled but is getting a water cooled conversion and a draw trough set up.

[B4S]

Very sweet .

FINALLY got my car up and legal to use as a daily now. Removed the nasty big 65 idles and went back to 58s. Cruises at 16:1, and goes 11:1 at WOT. I think I'll try my 122 mains (down from 130) with the 190 airs and see what happens. Then again, maybe I'll just let it be, since I rarely go WOT anymore at all. It's fueled perfectly for my needs, so maybe that is all that matters right now .

The stupid vac leak is back....same damn cyl too, #2. I pinched off the brake booster line, and nothing happened (well, the idle went up due to the fact that the CIS-E ignition is getting it's vac signal from the booster line). I truly think the manifold is warped, like everyone says, so maybe it's time to swap to the single sidedraft .

[B4S]

Hot damn I love these things. It's the most trouble-free setup I've ever had. My quick estimates on fuel economy are pointing at 30mpg, or at a bare minimum, 25.

I can't get over how well it cruises at 16:1 with the Jacobs ignition.

[WhiteG60]

Quote, originally posted by B4S »

Hot damn I love these things. It's the most trouble-free setup I've ever had. My quick estimates on fuel economy are pointing at 30mpg, or at a bare minimum, 25. I can't get over how well it cruises at 16:1 with the Jacobs ignition.

Come set up my stuff

[B4S]

I just had an epiphany...

I've been beating myself silly trying to find my cyl #2 vac leak. I've assumed that it's now at the brake booster line since it comes off the #2 runner. I can stall the car out by putting my hand in front of all the other three cyls, but when I do it with 2, the idle drops a bit, but no chugging or stall. If I had a leak big enough to keep a cylinder firing, I'd certainly hear it when I plugged the barrel, no?

The knock box is getting it's vac signal from the brake booster line I just realised. When I plug the barrel, the vacuum drops...which alters the vac signal to the ECU. Perhaps it's altering the timing to keep the car running? I don't think the CIS-E ecu is that advanced, but I'm really tired of taking the carbs off to track a leak. I'm solid mounted now, just some aluminum spacers with o-rings. No rubber isolators or thackery washers, just nuts and washers. I'm parking the car for a week, whilst on vacation, and when I come back I may just hit up the dyno and see what happens .

Oh, and I'm getting a CONFIRMED 31mpg hwy

[the12for12]

Quote, originally posted by B4S »

Oh, and I'm getting a CONFIRMED 31mpg hwy

Glory

[B4S]

Crap, the car was insanely hard to start today, after a day or two of sitting. Happened to see the fuel pressure gauge, and it read 1psi. I let it build, and it took a looooooooooong time to get to 3. Fired right up at that point...but the pressure quickly dropped to 1 again . The FPR doesn't seem to be able to bring it above 1psi anymore. It's a Holley 1-4psi one, luckily, since there are diaphram repair kits for $6 if that's the issue.

I'm leaving on vacation for a week, so this new issue kinda sucks. I'll be testing the pump, fpr, and gauge when I get back. I've got a spare pump, so no matter what it'll be a cheap fix.

Man...I wanted to drive it before I left .

[B4S]

Ha...problem solved. I made the feed line a bit larger and turned the fuel pressure up to 4psi. The change in the car is incredible. The flat spot coming off cruise is gone, and the acc pump is more sensitive. I love it.

Man, whoever says carbs are for cavemen has no idea what they're talking about...everything is a variable with these things. It really appeals to my technical side .

[impulse byer]

Hell ya I was told not to do it that i would have tuning problems and the would need work all the time. I say bull **** i have NO drivabillaty problems at all I can still pull 450k out of a tank witch is with a .91 5th gear in my rocco.

I have 283/279 cat cams and it will idle @900-1000 almost smooth in my 16V. I drive the car lots all summer almost daily driver witch is alot for me work is 500k a week before going to meets and track days.

[hmontaq]

Here is mine I bought before leaving the country. Barely got a look at it but its got dellorto 40s and a TT 288 cam. Problem is the 1.8 here is near dead. So bang for the buck I am not sure what to do. Any suggestions???

<br/>

[B4S]

Digi motor or JH? They're pretty easy to find, and cheap, since everyone tends to throw them away for larger/more powerful motors. I'd just replace it, why do you think it's dead?

On another note...I figured out where my vac leak is coming from. I remember now that I had one carb with a 'crunchy' throttle actuation. The bearing is done, boooo .

More of a reason to swap to my single DHLA setup for now, until I decide what to do.

[hmontaq]

Low compression in two cylinders and sounds like crap.

Not sure whats in it. I just know its a 1.8... So you think I should drop in a 2.0 bottom end? Which engine code and how much$$$ and HP?

[B4S]

Well, if you want a bit more grunt, grab an ABA from a MkIII. 2.0L is a nice upgrade from the 1.8 that is in there now, and they're cheap-ish. The block is 15mm taller than the 1.8, so you'll need to tweak a few things but nothing major.

Me personally, I love the high comp 1.8s that came in the MkIIs. 10:1 compression and 105 hp stock. People go out of their way to get rid of those motors for other ones with more power/status. I got one for free from a buddy, had 300+km on it, and after replacing the valve seals (easy job), it's going strong under the hood of my MkI. Doesn't burn a DROP of oil either .

[impulse byer]

Quote, originally posted by hmontaq »

Low compression in two cylinders and sounds like crap. Not sure whats in it. I just know its a 1.8... So you think I should drop in a 2.0 bottom end? Which engine code and how much$$$ and HP?

Yes aba would be real nice then you could run a serp set up it comes with. Or i got a free 1.8l mk3 cl(10:1cr ) bottom and used it i my old rocco made 120whp on cis people give them away both would be cheap and easy it would all bolt up.

But the 2.0l aba is a taller block so if you had a header it may not with that set up but if you have a manifold and downpipe like i did you just add a spacer.

[the12for12]

Quote, originally posted by B4S »

Me personally, I love the high comp 1.8s that came in the MkIIs. 10:1 compression and 105 hp stock. People go out of their way to get rid of those motors for other ones with more power/status. Doesn't burn a DROP of oil either .

BEST kept secret for carb applications

[hmontaq]

Its got a header of some sort. Anyone make a 2.0 header to fit into a MKII Scirocco?

[B4S]

The MkI stuff for ABA swaps fits IIRC.

Tried out some filters tonight, love the way they smooth out the incoming air, my wideband display slowed right down vs the cycling it does running open stacks. Hate the way it goes quite a bit richer, which means I hope the jets I ordered last week will tidy up the fueling so I can run the filters. Right now it cruises at 16:1, and goes to 11:1 at WOT, with the filters it cruises at 14:1 and WOTs at 10:1. If can get the cruise to 15-16:1 and the WOT to 12:1, I'll be happy.

I'm going to try some 125 mains, and 200 airs, vs the 130 mains and 190 airs I have now. I tried a few combinations of jets tonight, only to revert to the 130/190 combo. Here's what I tried:

-122 mains/190 airs/with filters = too lean under all conditions, but not as bad as with the 170 airs.
-122 mains/170 airs/with filters = too lean even with the filters on.
-122 mains/170 airs/7772.6 emulsion tubes/with filters = HORRIBLE.

I didn't try the 7772.6 tubes with the 130/190 combo that I run, because compared to the .11s it has now, there hole placement really points to very little low speed enrichment, which the 5 hole carbs need to overcome the leaner transition period. I think I'll just stick with the .11s, and jet around them.

One thing I did notice, was that the minute I tried the 122 mains, was that my cruising AFRs dropped from 13-14 with the filters on (at 130/190 jetting), to lean misfire leaner than 16 (my wideband only goes to 16). I didn't figure it was that big of a change, but apparently it is. It's perfectly clear that the idle jets alone do NOT control the cruise AFR in my setup, even though I've read that they should be. I may do some experimenting with larger idle jets and leaner mains after the next shipment arrives.

Good lord I love tinkering with these things! My jet box is growing FAST!

[B4S]

Arg.
So...according to the plugs, I have NO fueling issue on cyl #2, even though there is clearly some sort of vac leak.

It's a carbspiracy...they're out to drive me insane.

[B4S]

Should I swap?

[Svedka]

Do it I want to know if you like it I have a similar manifold I was thinking about using.

[B4S]

It's a tough call, to be honest...I love my duals, but I'm having a hard time proving the existance of the vacuum leak that I KNOW exists. I've narrowed it down to the left carb, but the darn plugs are all the exact same color after a WOT pull. I'd swap to the single in order to rebuild the duals, I've already rounded up a few of the Mikuni jets I'd need, as well as a larger needle valve (this stuff ain't cheap either! )...now I just need to find the courage to dismantle a setup that runs perfectly-ish.

[Svedka]

so do you think you will lose power high end and gain low end. What are you thinking is gonna happen to the power ban after going to a single, i've heard mixed reviews.

[B4S]

My duals are currently set up with 32mm chokes, and the cam I'm using has a 2500 rpm torque peak, so it's all low end right now anyway .

I'm not too sure what will happen to be honest, I'd expect a drop in top end, but the way the manifold is designed to take advantage of the firing order seems to point to it being a reasonably efficient performer for all situations. Each barrel of the carb is only in use by one cylinder at a time, with a static period between each event as opposed to the other type of manifold that puts each barrel into use on two cylinders at a time.

In the end, I haven't been able to find any solid info about how it performs because it's a rarely used setup on VWs, and the folks that have them don't seem to know anything about it or have anything to compare it to. I'd love to dyno the duals, then swap, but my slipping clutch might hinder my results .

[B4S]

Got a few more jets in the mail yesterday, so I spent this morning testing and tuning. Here's what I ended up with:

-7772.11 emulsion tubes
-200 airs
-58 idles
-no filters/socks (gave up trying to tune around them, the air was too turbulent, my mixtures were too inconsistent, and the acc pump response was horrible)
-127-128 mains (I say it that way because I'm not exactly sure what they are now. I took a set of 122s and drilled them out to slightly smaller than the 130s I had).

Right now, the fueling at WOT is ~12:1-12.5:1, and my part throttle AFRs are good enough to keep everything safe. I had tried some 125 mains with 170 airs (with the socks on the stacks), which was a bit too lean at WOT (13.5-14.5:1), and way too lean at part throttle (14-15:1). I may order up some 210 & 220 airs to put my WOT fueling exactly where I want it...but for now it's all irrelevant because my clutch slips pretty bad .

[Svedka]

I didn't see this so i'll just ask.
what size cam? Solid or hydro? any work done?

[B4S]

Hydro cam, "O" grind from a Canadian MkIII Golf CL (1.8, mono-point injection). I like this cam because the torque peak is at 2500 rpm, which makes for quite a nice low-down cruiser car. Low HP setup, for now. No headwork at all, except for fresh valve seals. I've got a stock Digi "G" grind cam (torque peak 3800) and a MkIV 2.0 stick that I may experiment with over time to see the differences.

[B4S]

Blew out the oil plug on the pan last night, luckily was able to cut it down before the oil pressure dropped. Got the car home and decided that was a good excuse to swap the possibly-leaky dual carb setup off and put on the single. Learned two things:

-the Rowland manifold is nice...but requires some grinding to fit.
-the stock dual downpipe manifold is nice...but requires some grinding to allow the Rowland manifold to fit.

So I ended up working in the garage for a few more hours than I figured I would. Had to remove some of the webbing on the dual outlet manifold (between 2-3) to get the Rowland to fit (loads of fun to do with a hand file while the manifold is on the car), but I made sure it fit before I quit.

[idrivemyself]

Did you take any pictures of your fitment issues?

[B4S]

I didn't, but have not mounted it permanently yet. I can snap some on the head/manifold combo that I used for mockup though, and show what I needed to do. The manifold really is good quality, and very beefy, it just happens to foul 26 year old exhaust manifold designs . If I were using this on a MkII, or with some headers, there would be zero issues. Luckily there was a lot of material to work with, so I haven't weakened it in any way.

[B4S]

Holy crap what a pain in the d**k the install was.

I guess the Lynx version would be a proper bolt-on, vs the Rowland "needs massaging and custom-made bolts". I guess you get what you pay for, and I'm still reasonably happy with the manifold, just a bit frustrated from a night's worth of troubleshooting an install I thought would be cake.

It's on though...

[vwbeaner]

I have been following this thread for a while and I think there is more info here than on the FAQs page, Keep up the good work

[B4S]

forgot to add the pic of what I had to do to make it fit against the stock dual downpipe.