SRX 800 stock pipe mod.?

Reimond

Reimond

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Nov 14, 2005
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I have trail ported Hauck 800 SRX. At the moment i have only stock pipes. How about cutting original pipes a little shorter (main chamber) to raise top rpm around to 8800rpm

Opinions please...
 
well is it a 780 or an 800? If it is a 780 the stock pipes work well at 8500. You could take a little out of the head pipe to spin them a little higher, but then you need different ignition. If it is acually an 800 (74mm Hauck makes both) then I would use the Bender big bore pipes. They run well at 8600 with the stock ignition.
 
It came with Hauck ign. box, no problem to rev it up.
Actually i have to check piston size, don't really know for sure. It also has 38mm flatslides on it.

Edit: pistons are 73.9mm
 
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If i use stock pipes on 800 engine. Is the main problem the chamber size or diameter of exhaust pipe (stinger pipe)?
 
Well thats a good question. Actually it should be both, but, you may get away with going to the next size bigger stinger. Which would not be optimum, but would make more power and retain the same running rpm. With the tight stingers the problem you'll have is on the long pull across the lake it will build too much pressure in the pipe and lay down up the other end.

If you must use the stock pipes I would go with bigger stingers. Having 38's should require even larger. If I had to use stock pipes, and it was just converted to an 800, I would use the next size stinger, with the bigger carbs I may go 2 sizes. Problem is realistically the whole pipe needs to be larger to be correct and get the best performance.

When I tested on the stock 800's, stock carbs, we tried numerous pipes, as well as modded stock ones and a couple we built from scratch. Though we could make a couple more HP, the best all around power band at relatively stock rpms were the Bender's. As well as it was less work. My trail sled was 168@8600.
 
Very good info, Thank you. Actually i can run these different set-up's on dyno, but i have to say.. I'm a little lazy-*** at the moment :dunno:

It's a little work to get those benders etc. here over seas, so this is why i'm askin all these stupid questions. Race aplications are different story, there is no shortcuts.

Reimond.
 
Actually if it is a race application it get's easier, you're not worrying about keeping the rpms down and run a higher engagement. I went through same issues with that sled, (2 different sleds) pipe after pipe, ended up at the same place, Bender race pipes, although thet do have an issue, it's easily corrected. That motor ended up at 201@9200 with 38's.
 
Good numbers @9200. My 780 had a little lower numbers with Huslers (@10200rpm) with DR set-up.

Let's see what i come up with this trail stuff..
 
Could some one tell me what is recommented pipe pressure if i try different stinger pipes set-up's?
 
what you need to look at is the amount of heat your putting in the pipe and the piston crown, the smaller the stinger the hotter the pipe and the piston, great way to wake up pipes for short drag racing runs, especially the bender big bore pipes, they are made to run across the lake wide open for a mile. The best way to check is to install bolts and nuts welded into the stingers and keep track of the number of turns your reducing the stinger by turning the bolts in reducing the size of the stinger outlet size, then after running on dyno you want to remove the cylinder and piston, look up inside the piston dome on the bottom side, you want this to look like a hershey bar brown when you got it right, if its all black and wet its too big yet, if you go too tight you will get whats called "death ash", ya dont really need a explanation of it with a name like that.

easiest summary is tight stingers work for 500ft drag motors, they will not live on lake race stuff, you need bigger stingers to run a engine wide open for long distance, it keeps the piston from running as hot.
 
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