[Diy_efi] re Throttle body sizing

[William Shurvinton]

I dunno. I still reckon that, provided you can hit the tip in with your
accel strategy SD will work well with hoopy cams. I've seen SD working on a
motorbike engine and that's fairly cammy. I've had my curiousity piqued by
someone who has gone in print saying 'big cams and plenums don't work
together'. It's one of those red rag to a bull things, but will have to wait
as I don't have a suitable engine to test on. FWIW the tip in problems seem
to start occuring near the 100HP/litre mark. Once the throttle is open
things run fine, but drivability sucks. Solution: IR. Seems an expensive way
to cure a tuning problem.

But yeah, of the aftermarket stuff if motec can't do it then it likely can't
be done.

One day i must see what the IAC valve is doing on tip in on the wifes car. I
wouldn't be suprised if there is something going on to deal with this.

Bill
----- Original Message -----
From: "Dave Dahlgren" <ddahlgren at snet.net>
To: <diy_efi at diy-efi.org>
Sent: Wednesday, October 16, 2002 1:07 PM
Subject: Re: [Diy_efi] re Throttle body sizing


> A motec handles these TB sizing issues quite well. Alpha-N fueling is a
must in
> anything with a huge Tbody on it compared to what might be optimum as
well. The
> wilder the cam and larger the intake tract gets the more you need
alpha-n..
> Dave
>
> William Shurvinton wrote:
> >
> > If you have an advanced enough ECU.  However better engine tuners than
me
> > have failed. It would appear that you need an additional type of accel
shot
> > that works off very small throttle openings. It also 'may' only be fully
> > alleviated with sequential injection. Not many have this feature,
although I
> > am willing to believe that there is stuff for that buried in GM code.
> >
> > I have yet to find an aftermarket unit that would cope with this though.
> > Must be one out there.
> >
> > caveat: all the stuff I have direct and peripheral experience with has
hoopy
> > cams in it, which may not help.
> >
> > Bill
>
>
> _______________________________________________
> Diy_efi mailing list
> Diy_efi at diy-efi.org
> http://www.diy-efi.org/mailman/listinfo/diy_efi


_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://www.diy-efi.org/mailman/listinfo/diy_efi