dizzyj

I have this on my race car. Only issue is it seems that I lost about half of my pedal travel. Figured I could machine a new cam that is bigger. Anyone have any experience with this tb?

George D

No issues with pedal travel after spring rate change and cable adjustment.

333pg333

Didn't Sid or Shawn run one of those T/B's ?

blown 944

I have one, I modified it to use the stock throttle cam. It's been a long time. I'd have to figure out what I I did to fit it again.

dizzyj

Can you describe what was done?

Mine has a machined can on it

dizzyj

Here is mine

blown 944

I'll take a pic in a couple hours when I get home

Jon951

I have 3" Ford throttle bodies on two of my 951s. The Linsey Racing intake manifold was modified to use a straight 3" pipe rather than tapering to a smaller size. However, other than a more reliable, cheaper and modern TPS I'm not convinced this is a worthwhile mod to the LR intake manifold for an 8valve head.

George D

Use the stock cam. Springs used were trial/error stuff without driving. Pedal work/watching cam movement at TB with me sharing the pedal feel. Tom sent me springs years past - took a few SS spring rates to find what I preferred. Those rounded cable/cam setups aren't linear. Nothing else I own burning oil/gas, etc. has a cable running from throttle to fuel mandates. Circular wrap of cable from foot position will go WOT much faster than a gradual stock cam housing - those 360 degree TB cams were designed for NA engines.

G

dizzyj

Can I stick the cam from my 951 tb? Or is the 928gt cam different?

If the cam shape is different (not circular) then that could explain the difference in pedal feel

George D

That's the issue. I don't know if the stock 951 TB cam is the same size as the 928 - knowing Porsche/good engineering it's likely close to identical. Close ups of mine.

G

George D

The return spring under the TB for immediate close/lifting foot requires a few spring rate/length attempts to get what you want in terms of pedal feel and reaction time. This pic is with the TB fully open - you don't want the possibility of binding causing part throttle or the cable slacking enough to come out of the cam groove.

George D

I'm not following - this 928 TB is 75mm/2.95" using an internally modified runner SFR intake with matching diameters prior and post TB. Ford TPS's may be cheaper, but not higher in evolution or more reliable. Not knocking you here - simple curiosity understanding your comment.

G

Jay Wellwood

How does the 928 TPS compare to the 951 TPS? Same micro switch and resistance values?

Jon951

Jay and George I Do Not know if one is better than the other, my bias would be toward the 928. My decision was based on experience with 25 year old very well used 951 TPS, and availability when the builds were in progress. Availability for replacement at the track was also a consideration.