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spuggy spuggy is offline
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Join Date: Jul 2003
Location: Glorious Pac NW
Posts: 2,831
Quote:
Originally Posted by patkeefe View Post
72 PSI is spec for an SC head, which I think is all I can get from the SC pump. At 72, I just about run out of fuel at high RPM, according to the dyno sheeets. So, I have too much in mid range, and barely enough at top end, hence the consideration of series sequential pumps. I'm just trying to figure out how to turn the second pump on.
Pat
Pat, a Bosch 044 motorsport fuel pump might be an option. Cheaper than most stock pumps (I paid $200 US for a brand new one) and the specs are much better than anything the factory fitted.

Bosch are very conservatively rating this pump too - I've seen people claim it out-flows the Walbro "300 l/p/h" pump and makes higher pressure doing it, even though the official spec on it is only 200 l/p/h according to Bosch. Stock fitment on 500HP Cosworths.

That's all I have - my only fuel pump, fitted in the stock front location - and my system pressure doesn't twitch under full boost.

I also tend towards taking off the RPM solenoid and tuning the WUR. Mine was fitted (but not plumbed) for the dyno runs - turns out it wasn't needed, did everything on the WUR. Took it off in the end.

What boost pressure trigger did Brian Leaske set your WUR for? IIRC, mine came set for 6 or 7 PSI - which wouldn't even trigger on your car, @ 5...


Have you asked Stephen if the IA-modified head is non-linear in the mid-range? That seems odd, if the classic CIS tuning problem seems to be a pig-rich mid-range to keep the top safe - so, if anything, I'd have thought they'd have made the top range pig rich and left the middle alone (or just slightly fatter)? But obviously he'd know for sure.

HTH.
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'77 S with '78 930 power and a few other things.
Old 01-03-2008, 07:32 AM
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