ST170 Throttle Body Air Flow Setup

[escos]

Not sure if my description is accurate or not!!!


However, I've just put my engine back together after having the head ported by Andrew at ALD. No other changes have been made and I'm sure there are no air leaks.

The issue is that I'm running very lean on the lambda after starting her for the first time, I got my schronmeter out to measure the air flow through each of the jenvey throttle bodies, on all 4 I'm reading a value of 7kg/hour, now I thought but can't be sure before the work they were sucking 4-5kg/hour, it my uneducated mind it seems to make sense that after the headwork it able to suck more air, however what I don't know is how much air I should be using per hour.


I'm due to go for mapping early August and I'd like to get it running reasonably well before then to put a few miles just to make sure I'm happy with everything first, can anyone help with what I need to set the throttle bodies to?


Thanks


Ben

[Graham]

with shut throttles you wont see much difference in airflow by porting the head, unless the valves are now seating better.

If your seeing significantly more airflow its likely that the throttle position is very slightly different, at idle a very tiny change makes a big difference to the airflow

[escos]

I did have new exhaust valves whilst the head was being ported, but again my limited knowledge doesn't know whether that will be a reason or not!!!!

I will take another look at the throttle cable, just to make sure it's not holding them open and causing the issue. Once that's done I'll reset the TPS and see what happens, failing that I guess it must be an air leak somewhere, so time to get the soapy water out....