Throttle Bodies

[cerbhead]

I posted this against an old thread and think it got lost there....

I've been looking at the throttle bodies as part of the engine rebuild. I have made some pics and notes for anyone interested. Unfortunately there are more probs than just the ridges to overcome as mentioned in the old thread. On my car, each cylinder's TB is slightly different - eg different height ridges in different places - as the maching is not correctly aligned in the casting. The even and odd bank TBs are also slightly different.

http://i40.photobucket.com/albums/e23
http://i40.photobucket.com/albums/e23
http://i40.photobucket.com/albums/e23
http://i40.photobucket.com/albums/e23
http://i40.photobucket.com/albums/e23

All in, some pretty big flaws.......

[trackcar]

or not ...


when I was chasing the first 400bhp from ceejay's car I did all the usual inlet stuff like thinning the spindles, taking out the lumps and bumps and making sure the inlet went from small bore to slightly larger at every junction to keep flow up and minimise flow reversal at low rpm, heat reflective lagging everywhere on the airboxes, no oil breather into o/s airbox etc etc etc .. result of many hours labour was less than 10bhp on a car that produced 400 noble motorsport bhp

on an otherwise std car I doubt you'd see any gains worth the effort

[cerbhead]

trackcar said:

......... on an otherwise std car I doubt you'd see any gains worth the effort

I agree. On a std car the TBs are a minor issue compared to things like ECU mapping, trumpet length, head reworking (Red Rose), and exhaust manifolds. I bet 10 bhp could be had by just setting the cam timing correctly to suit the engine. But at higher states of tune engines are more sensitive to anything that restricts gas flow, so for an ‘ultimate’ development, once all other mods have been done, then making up custom manifolds with new throttle bodies with an unimpeded inlet tract without tight bends etc would be a logical step. A relatively big job, and certainly not one to be judged on bhp-per-buck - but 10bhp on top of 440bhp would be a real big difference for some people even if they couldn't feel it on the road