Front Facing Plenum

[66yostagea]

I have finally completed fitting an FFP to my 25DET, using info from ix9 DIY. I now have an N/A 25DE Stag I want to convert to turbo but first want to adapt to FFP. I have heard that there have been conversions of the stock upper half by blanking off the OEM intake, then boring out the front end and weld in a mating flange for the throttle body.

Anyone out there done this or know of anyone who has?

Thanks in advance.

[TwoCents]

I hear it makes things worse. It ruins the air distribution to each cylinder as the inlets are not tapered like a proper aftermarket system.

[89CAL]

I know someone who has run a modified standard plenum (converted to front facing) in his RB20 powered 180SX for a while with no real issues

However in saying that, with the time and effort (and cost?) involved, you may as well try and find a good greddy copy plenum and use it.

Thats what I've got, I got mine in a trade because the person wanted something but didnt have the cash i wanted, but I thought why not, and its run fine with it on

[mad082]

the stock plenum was designed to be side facing. adapting it to be front facing will deliver uneven airflow to the cylinders. this will eventually destroy the motor due to the fact that the front few cylinders will run rich while the rear cylinders will lean right out (but overall AFR will still be the same so you won't know that it's happening unless you inspect your plugs regularly as well as measure the AFR of each cylinder individually).

[66yostagea]

Thanks for the info, you have talked me out of it.The N/A is RWD, and on looking there is more room to get to the plenum bolts from underneath. The RS I fitted the FFP to is AWD, it took months, about 20 slabs and three packets of band aids.

[lammy426]

mines been done for 3 1/2 years and no probs the same as many others in the uk, running 395ath ,the only probs i.ve heard about is when they already have engine faults,comp and injectors mainly,i take my plugs out every 3000 miles when i change the oil and they have always been spot on