Darien

Any idea what I've been losing if anything with the T-body butterfly not fully opening when gas pedal on the floor (see pic)?

http://forums.rennlist.com/upload/tbody.jpg

inactiveuser92616

you will certainly lose some efficiency and power without being able to hit WOT, how much depends on whether or not it is the main restriction in the system at mostly open throttle.

FlyingDog

Can you turn it more with your hand on the throttle lever? I don't think mine makes it to 90*, but it gets closer than that.

WYAIT, spray some throttlebody cleaner in there and clean up.

Tony

yup! he defintiely had more travel left when moving the thottle link at the throttle body.

My other concern was he actually getting the WOT switch to activate at that point and thus using the WOT maps for full power?

Bill Ball

You probably have slack in the cable section between the pedal and the throttle quadrant. There is an adjuster at the firewall. Adjust both sections of the cable so there is barely any slack but the throttle still freely drops to the stop and you hear the throttle idle switch click.

hacker-pschorr

My 81 was doing the same thing, cruise control cable was holding it back.

FlyingDog

Bill got what I was thinking.

Tony, You should be able to test for operation of the WOT switch. You should know that...
https://rennlist.com/forums/showthre...OT+switch+test

Tony

I didnt have the manuals with me. This is on an 86.5 which may be differnt. You can hear the idle siwtch "CLICK" but i wasnt sure if there is a "CLICK" at WOT as well. In the postion shown in the pic, there was no click/switching yet.
Its all for naught anyway, a SC is going on and the throttle WILL be set correctly.

heinrich

Won't gain much. But do get rid of the sand on the throttle though

Tony

Under boost, well, suction for a Twinscrew I guess, this is a HUGE restriction .
It will be spotless when it goes back together...as they should be.

FlyingDog

That explains the scurry to get everything fixed up correctly. One of DR's?

UKKid35

No click at WOT, and it operates anywhere from 3/4 upwards.

Tony

Nope.
Unfortunealty It was purchased before DR's creation came out of the closet.


Darien and I will get it dialed in, in due time.

after i tossed the image on CAD and measured it (not to scale, but the difference in values is the same.

Looking at the frontal area to the airsteam...give or take....
2647 for the throttle bore
1327 for the butterfly

leaving a total area of 1320...looks like a restrictionof appx 50 % to the frontal area to me ..if thats the waythis flow stuff works???

Bill Ball

Yes, I think this will have an effect at the top RPM when airflow is really sucking the daylights out of that small throttle body. Snugging up the pedal side of the cable should help a lot. You can get fooled by looking at only the second of the cables, between the throttle quadrant and the linkage, and seeing no slack there. Most poeple don't check the first cable.

The cruise control cable should be set a GOOD amount of slack. It should NOT be snug - far from it.

Imo000

My ’85 was just like this when I bought it. The linkage for the ’85-’86 can be easily adjusted. It’s located on top of the fan bracket. Loosen the nut on the linkage arm and screw the rod in until there in only about 1-2mm play left. I bet you’ll feel an extra 20-30hp gain.