Can you get 300bhp with an airbox?
 

Hi, I have a 1997 uk turbo mapped by JGM, when I first got it mapped, vf23 440s, sti tmic, full decat,airbox and green panel filter, it made 292, but the airbox was holding it back at the higher revs, put on an apexi induction kit and it made 305 bhp.

Now, I know Induction kits should be used with FMIC, but I was wondering, can you actually make 300 bhp with an uprated panel filter? As it's going to start getting warmer I'm considering fitting a cold air feed from the bumper up the wing, or putting the airbox back on.



Also, why do induction kits not affect MAFs with a FMIC, but do on TMIC, is it to do with airflow?

Many thanks

Of course. Whether there's something up with your particular car Simon will know better than anyone else but in general, it's no problem at all to go a long way beyond that number on the standard classic front entry induction tract and panel filter setup. The newage one is better again.

They do affect the MAF, irrespective of the type of intercooler that is used. However, it's pretty much impossible to fit most FMICs without junking the standard intake arrangement, so if you want a front mount, it's something you've just got to live with (and/or map around).

So, is it worth putting the airbox on, jgm said he mapped it safe, if I keep the induction kit is a cold air feed pipe recommended? Thanks for your reply it is nice to get a genuine answer

If JGM has mapped it the way it is, I wouldn't change anything without checking with him first. Swapping from the induction arrangement you're running now to the standard one is likely to impact the mass airflow voltage scaling to some degree. Any changes should be benign going in that direction, but all the same, Simon knows your car better than any of us here. He's the one to ask.

Its a 98 and the airbox isn't wonderful for flow.. the engine is a bit tired is it 115k now David? there should be no issue through the summer on the induction kit you have the maf and ecu will compensate a little for the extra heat safety wise but it might just run a little less power.

the induction kit just helped it breath a little better.

Simon

Have ran in excess of 350bhp on the standard airbox on 98 cars, but on larger turbos.

snap.. this one just wouldn't get the desired 300 on the vf and airbox :)

Is the Airbox standard ?

On a modified 98 airbox 350hp is obtainable with a vf23 on an Sti.

It's a 97 uk turbo and os now on 124,000 miles, so I'm not going to mess it around too much, I think I will fit a cold air feed see if that helps, also, the apexi ecu has a knock counter I will keep an eye on.
Thanks

how would you modify the Airbox?
Thanks

Remove snorkel

Enlarge entry to about 90mm - its much smaller stock somthing like 76mm from memory. So you make it about 40% bigger in area.

Run a 90mm cold air feed to the foglight area.

Here's an article on an earlier wrx - the priniciple is the same even tho the airbox is different.

http://autospeed.com.au/cms/article.html?&A=1605