is it possible and safe to run a turbo with a 4" inlet thru your stock afm.. has anybody done this before or can i put in a bigger diameter afm.. cheers

The only thing you have to watch is maxing out your AFM signal output of about 5v for full logarithmic scale for max airflow and this can happen at around 14psi boost with a T3 and an IC. So if you are running below that then there is a fair chance it will be ok, however, if you are close to the AFM max then you will also likely be close to the injector max pulse width. If you now have standard VLT ECU and want to change for a larger dia AFM then it will very likely have different output curve for the same flow this will mean a retune of the existing ECU (if you want) or a different ECU that is easier to tune. Having a smooth and gradual change from 4" to suit AFM output is not hard and can save a heap of time and trouble if you are well below the approx 14psi issue,

get an aftermarket ecu as no doubt that turbo with the 4inch inlet is suited for 300rwkw

Quote: Originally Posted by Niche The only thing you have to watch is maxing out your AFM signal output of about 5v for full logarithmic scale for max airflow and this can happen at around 14psi boost with a T3 and an IC. So if you are running below that then there is a fair chance it will be ok, however, if you are close to the AFM max then you will also likely be close to the injector max pulse width. If you now have standard VLT ECU and want to change for a larger dia AFM then it will very likely have different output curve for the same flow this will mean a retune of the existing ECU (if you want) or a different ECU that is easier to tune. Having a smooth and gradual change from 4" to suit AFM output is not hard and can save a heap of time and trouble if you are well below the approx 14psi issue, yeah still standard ecu and all else u mentioned.. i just about to run the engine in over the next couple of weeks with the stock t3 then upgrading just after chrissy(as i haven't decided what turbo to get) i will be uprgading to something around a .64-.70 compresser with .84-.96 turbine.. once thats done i'll only be running 5-7 psi for awhile till i get injectors and computer.. but i was just making sure that the afm would work with new turbo, so has i didn't have spend all my moneyss at once...... i still need money for drinks.. thanks

There is this site which might be helpful for your current ECU and might be cheaper than any other (new) aftermarket ECU, http://www.nistune.com I havent tried them yet but might in the next couple of months,

Defently Niches right save for injectors/pump and ecu first before the turbo! Ecu's and injectors are fairly cheap anyway Running that size turbo with stock managment is gunna be a pig to drive anyway. Get all the parts together and do it in one hit, u wont regret it Some original photos have not been recovered yet.