Borrowing some VW performance...

[justrhines]

Hi All,

Been fooling around looking at the turbo blowthrough kits on CB Performance's website. The VW guys put these kits on their dual-IDF setups with a T3 turbo. Requires a turbo plenum over the carb(s), turbo emulsion tubes, a pressure-adjusted fuel pressure regulator, and of course the turbo setup. Anyone considered this in the past?

Justin

[SteinOnkel]

As a huge VW nut: I would not borrow any of their "performance" parts from their air-cooled (junk) engines.

The average air cooled hotrodder is a bit...how do I put this? Unsophisticated. Meaning that they are perfectly fine with AFRs of 10:1, eye-watering rich exhaust fumes and replacing plugs every 2000 miles because "Well, it's an old car!". Which is complete bunk in my opinion.

So, if you want to ruin your mileage, longevity of your (comparatively) very modern engine and have all the drawbacks of dual carbs PLUS the drawbacks of boost, have at it. As an optimistic estimate, I would say it will take a year minimum to get it dialed in to where it's at least decently driveable. Without even looking at the setup: let me guess, no chokes on the IDFs, right? There you go. Oh you "just" gotta hang out with it for 15 minutes on cold starts...

I've used CB Performance parts in the past for my water-cooled VW and they are okay-ish, not great. The black box is pretty neat, but outdated at this point. I wouldn't consider it for a Fiat though, as there are far better OEM ignitions available to us.

Cheers
Steiny

[Nut124]

I'd listen to Steiny on this one. The average guys will struggle to get dual IDFs to run well w/o the boost.

If I had to do boost, I'd want to have EFI and fully programmable ignition. I think N/A twincams are cool when properly built and well running, though.

[SteinOnkel]

I'd listen to Steiny on this one. The average guys will struggle to get dual IDFs to run well w/o the boost.

If I had to do boost, I'd want to have EFI and fully programmable ignition. I think N/A twincams are cool when properly built and well running, though.

You hit the nail on the head. My VW has a 1.6 16v, w/ ITBs and programmable efi. It's a riot.

If you really want some performance out of a Spider (and don't care about originality, as is probably the case if you are considering a turbo dual carb setup) I would bin the entire engine and transmission setup in favor of something out of a miata. Get the flyin' miata kit with all bells and whistles and you are off to the races.

Or a k swap, those are beastly engines too.

[Nut124]

Back to the VWs for a moment; when I went to the drag strip last fall, the lines were long and I spent some time with two older VW bug racers. They were running low 13's at 1/4 mile! I was pretty amazed.

These were were N/A, air cooler VW engines with high CR and big cams. No bottle. Likely producing 220+HP or so on engine, maybe more. The cars were stripped down. They were trailered whereas I drove my Fiat there and back. Remarkable regardless.

[wetminkey]

Yup! BEWARE! My nephew races VW types at Bandimere Raceway in Lakewood, CO,...Amazingly fast little VWs can be built!
I've got a '72 Superbeetle, and it's unsophisticated,...but cute.

[justrhines]

Thanks for the advice all! It does make sense to switch over to EFI for a turbo setup, didn't even know someone made a blowthrough setup for the IDFs until I saw CB's parts.

As for the VW gurus... they are in fact a different breed. My folks are from the SoCal area where the air-cooled run rampant.

As for now, I think I'll be milking my IDF's and headers for a bit more HP with cams and pistons. As fun as a Miata swap sounds, still seems a little sacrilegious.

Justin

[Nut124]

Justin, do you think you have gotten your engine and IDFs running as good as they can? What cams do you have now?

Do you have any test or benchmark data as to how much power you are making?

[justrhines]

Nut,

Quite frankly, I'm nowhere close. Haven't had the time to replace the stock cams, so this is to be expected (next item on the list). Just have the dual IDFs and Vick headers + 2" pipe throughout.

Best "data" I can give you is a couple seconds off the 0-60. Have you got to dynoing your new 1800 build? I know you're not quite happy with the 40/80 cams... are you moving to some higher duration cams?

Justin

[Nut124]

Justin, no, I have not dynoed my car. I did call last fall but the dyno guys were too busy until the snow fell. Based on the 1/4mi time slips I'd estimate 130-140 modern HP.

The 40/80 cams run awesome in my car and I should just leave them alone. But I like to tinker and push for more, I quess.

I did but a Dragy device. It can produce 0-60, 5-60, 1/4 mile etc times. I plan on doing some more bench marking before any cam swap.

[justrhines]

Nut,

Great- keep us posted! Would love a data dump of your performance specs sometime as a benchmark for NA builds.

Justin

[F16Waldo]

I did but a Dragy device. It can produce 0-60, 5-60, 1/4 mile etc times. I plan on doing some more bench marking before any cam swap.

I'd never heard of a Dragy device...looked it up and went "WOW". Yup, bought it...arrives tomorrow.

Keeping with the VW theme, first vehicle I'm going to measure is a 92 Corrado I just picked up with multiple mods to the VR6 engine. Curious to learn results as the Corrado is much quicker than my Touareg Hybrid which will do 0-60 in 5.8 seconds according to spec sheet.

Spider will get tested once it gets a little warmer out here in the Mid-Atlantic region.

Every time I log onto this forum I learn more interesting stuff!!

[Nut124]

Waldo, the Dragy is a good deal for what it is. I tested it a bit last fall before it got cold.

I friend of mine had a -92 or so VR6 Corrado. It was not super fast but it was bone stock. How do you know yours is so fast?

Do not expect too much of the old Fiats. Contemporary road test data shows 0-60 times in the 10-13+sec range. The fastest tested in the US I saw was the 1800 Abarth @128HP: 17.1s 1/4mile. Most 124 other Spider models tested were 18-20+sec 1/4 mile. I have a 15.75s time slip from a local track.

[justrhines]

Out of curiosity, what is your 0-60, Nut?

Always seemed interesting to me that the Fiat group does not have many guys who are really into the drag racing scene to the degree that the hot-rodded VW guys are. There are some 1776cc VWs hitting insanely fast 1/4 times...

[Nut124]

Justin, I really do not know what my 0-60 time is. 0-60 time is likely the least consistent benchmark of power due to the short duration. 1/4mi trap speed is a reliable benchmark of power.

I'm not really into drag racing. I only go there because it is the only way to get reliable performance benchmarks.

Looks like my time slip shows 1/8mi time of 10.07s at 69.5mph. Then again, at the strip, they use last 60 or 100ft average for the speed, not speed at the line. If you plotted the times, speed from the time slip into a graph, I think the 0-60 would be in the 7-8 sec range.

Execution of launch and shifts affects 0-60 time a lot.

The factory rear end will break if launched hard with sticky tires and good power. I have broken 3 diffs. Now running the ruski LSD. Good so far.