Do you like to go fast? Well get out of that stocker and build a hipo motor for your VW. Come here to talk with others who like to drive fast.
5 posts • Page 1 of 1
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- Joined: Wed Nov 14, 2007 5:19 pm
The RetroRacing Super Beetle as most competitors see it, all aft-end. Standard stinger on duty.
The drag race crowd doesn't have the problem of some Rice Grinder trying to draft you at a foot off your tail. Racing LeMons, we've lost a few stingers over the years. And length is not the only problem. Even at the track, a stinger makes us among the loudest cars out there, and we're above some decible limits.
Rather than go by theory, we decided to modify a stinger or two, trek to the track in our HSR Ghia,, and see what happens. By the book, if you cut down a stinger on a 4-into-1 collector, you loose low-end torque. Wide open throttle power is largely unaffected. So we cut a stock 17" EMPI stinger to about half length and bolted a short (3") motorcycle baffle into it. The motorcycle baffle had a perforated center pipe in it,
The engine was a high-winding 1915, 42x37.5 valves, 1.25 rockers, Engle W140 cam, dual Weber 48IDF's, on 38mm venturis. This was our Bonneville engine from last year, the compression dropped from 11:1 to 10.3:1 for road racing.
With the short stinger, we had no power above 3000rpm.
Fitted with the standard length stinger and a standard EMPI baffle (but no fiberglass batting) the Ghia was soon flying as per normal, 6500 in 3rd . The Grand Prix track is too short for our 3.88 final drive.) There was no reason to make more laps with an unbaffled stinger.
- GS guy
- Posts: 776
- Joined: Wed Nov 06, 2002 3:01 am
FJ, your post reminded me of a slick looking Sun Bug Beetle I used to see daily back in my HS days (mid/late 70's). What I found very unique was the exhaust - this was largely pre QP days, so most Beetle performance exhausts ended in a glass-pack muffler of some sort, or stinger. This particular Beetle, however, had twin stingers coming off the collector, each one pointing off to the side of the car and angled slightly down. Probably baffled as it wasn't too loud, although it probably had an otherwise mostly stock engine (maybe a Bugspray under the hood?). Never seen another exhaust like that one, of all the hundreds of different manufacturers and designs produced over the decades. Having a (or 2?) stingers come off your exhaust mostly parallel to the lower support bar might alleviate the "shunting" problem and who knows - open up a few more ponies?