Quote:
Originally Posted by Nux
I took my car for the first drive yesterday. My build is: 3.2SS single plug 9.3CR, DC20 cams (113 lobe), 43mm Triumph ITB's (thanks Clay!), Megasquirt EFI, classic retrofit CDI, straight headers and Dansk 2 out.
I've balanced the ITB (maybe it needs a little more), set timing and a very standard first AFR tune.
OMG she pulls like a train!!! And the roar from the stacks is amazing!
I few questions: Even though I have an extra spring on the linkage, I have a bit trouble getting all the way back to idle. I can manually press it back. Any good ideas?
And: I noticed during my short frist drive, that MAP seems significantly higher with ITB's than with plenum? It's maybe a stupid question but: Is the value in tunerstudio (20 - 100) a percentage or real value?
I'm working on the lower rpm's as I get backfires trough the ITB's and the throttle response is not too good. It pulls VERY hard from 4000-7000.
Short video:
https://youtu.be/9dfqiRvUgJ0 |
Nux,
Greetings and excellent work on your part. You may need more return spring, but, one thing I've found with the Speed Triples is that you may need to loosen the two screws that fasten the butterflies to the shaft and then let the spring force close the butterflies. this tends to help to self-center the butterflies in the ITB to minimize any rubbing/friction caused by them not being perfectly centered in the throttle body.
Make sure you have the ITBs balanced well. Follow Clay's guide to getting them balanced. The next thing is to datalog and review what is happening to your AFRs ...backfires thru the stacks typically indicate,,unbalanced ITBs, bad timing and/or lean conditions...while popping thru thru the exhaust is often a rich condition.
MAP readings are in kPa and not in % and can be higher with ITBs than common plenum.
regards,
al