I just got done installing a greddy fmic on my car which is a 88 T2. I have a turbo xs mbc,and a s5 turbo with a ported wastegate. Now I did not adjust my mbc after installing my front mount and I am now seeing boost levels as high as 14-15psi on my boost gauge,where as before the front mount, I was only seeing boost as high as 9psi. So my first question is what is causing this sudden increase in boost pressure? Secondly I have a dynotune EGT installed in my DP right next to my O2 bung,and again before the fmic I was seeing egts only up to 720c,and now with the fmic my egts are climbing to 820. Now I do have a upgraded walbro fuel pump that is rewired,720cc secondaries,and a safc. I tried richening my mixture with safc to lower my egts, but when I get above 15% on my safc, my car starts to misfire bad if I am at wot,so I have to back down my safc settings to like 11% and it doesn't misfire anymore but then my egts start to climb. Any Ideas as to what maybe causing all this? Any help is appreciated, thanks guys!!

 

with only 720's and S-afc I think 15psi is way too much for starters. don't floor it till you figure out how to lowre it.

I would check your boost controller. did you just install it now? or was it in before when you were runing 9psi? turn it down and see if it does anything. if you just put it in. maybe it's cranking the wrong way.

turn your CAS (timming) back a few degrees. you should do this if you are running more then 10-12psi with an FCD.



once you get your boost levels down. please find a wide band o2 sensor and a tuner to tune your A-afc for you before you blow your engine up.

 

No the boost controller was installed before the front mount and I was running it before and it was keeping my boost to 9psi. I did not adjust it after I got the FMIC, the boost controller is in the exact same spot as it was before the front mount. And that spot was screwed all the way down on the controller so I can't lower it anymore. I am going to be taking the car to chris sanders(BlueT2) to have it wideband, but until I can I just want to make sure I'm running at safe levels. I don't understand why my boost has increased so much.

 

yikes screwed all the way in ??

maybe it's right for that one. but most MBC should be all the way out for lower boost.

hook a hose right from the wastegate to turbo to bypass the MBC and see what happens.

 

if it's a ball/spring boost controller then it should be all the way out. If it's screwed all the way in you're getting the maximum possible boost with that controller.

 

it's just the turbo XS boost controller that has the little allen head that screws in or out

 

Yeah, the "ball and spring" type screws out to lower boost and in to increase boost. You need to find out what kind yours is.

 

well according to turbo xs homepage I do screw it in to lower the boost, the mbc even has a sticker on the side of it telling you which way to turn the screw to increase or decrease boost

 

Well how about bypassing the mbc like Scott recommended.

 

Well Dale always told me boost response is better with a good FMIC than the stock i/c. Maybe its just that much better of a design?

But Scott, theres no way hes running lean on a stock turbo. With 720s and an upgraded pump he has to be running rich. I run 720s with my upgraded turbo and run pig rich up to 14.5-15psi. I'll be able to get A/F #s soon to prove it though.

 

The EGT's are higher because of the extra boost. EGT's also a very hit-and-miss way to tune, especially for someone with (I'm guessing) very little tuning experience. Stop messing with it and get onto a dyno. Have it tuned by a professional with a wide-band A/F meter.

 

It must be all that added pressure drop and lag with the FMIC huh?

Daniel

 

Since you bought the Greddy FMIC sounds like you have a little coin. Why not build your own wideband and sell your EGT on ebay for a little money?

www.techedge.com.au/vehicle/wbo2/

 

Watch those Tech Edge Widebands... you should calibrate it after you build it by checking its reported number against the number gained from a more expensive (professional) unit.. they've been known to be off by a complete point of A/F ratio when compared to the wide band on the dyno...

Also.. Your Boost is increasing because the FMIC is MUCH less restrictive than the stock TII intercooler, the EGT temps are going up because you are putting a denser air charge to the rotors and, thus burning more fuel.

I would suggest switching to a manifold with an external wastegate as well, even ported, the stock wastegate isn't going to handle that much airflow....

 

Haha...maybe we should link this for the brainiacs on the other thread...

 

Well I made an appointment to have it wideband by chris sanders in monroe michigan

 

I guess i'll find that out soon enough I'm just waiting for my o2 sensor to arrive and then i'll throw it on the dyno and just do a couple of pulls to see if they are the same or what not. I heard that the TE were at most +/- .1. hopefully they are cause I can live with that.