Given that the standard TB has 52mm and 35mm openings, giving about 31 cm^2 (ignoring obstructions), should I go for 40mm (50 cm^2) or 45mm (63cm^2) TBs? My EFI specialist thinks 45s but I think it is overkill.
all depends on the level of tune, or the planned level of tune. 45's on an otherwise standard 1.8 8v (i'm assuming) would reck low and midrange due to low overall gas speed)
All depends on how good the mapper is too, my friend ran an otherwise standard 1.6 16v peugeot engine on 45mm tb's and made decent power and torque throughout the range. Edited by: Sam_Rallye
40's im going for on a 1.8 8v You dont need as big a throttle bodies as carbs, because fo the way they work.So that probally isnt as small as it sounds... What sort of revs were you looking at pulling ?
Only 7000RPM with the hydros. I'm thinking 40s. That is still a HEAP of area when you multiply it by four.
The larger trottles will give a more 'on-off' feel to the trottle at very low openings, meaning traffic, so might not be appropriate for a daily driver. Jai