My big28 upgrade problem

[ozzeran]

Ok howdy all, I just recently installed a ported FP big28 brand new lastnight, I went ahead and installed a walbro 255lph HP pump as well. With the boost at 14-15psi it feels A LOT slower than my t25 did. I talked to several tuners and they told me that my big28 at 14 psi will be much more improved versus the t25 at same boost. I dont see any diff, just seems slower, no more kick in the pants. The install went well, no leaks, good idle vaccum readings. I am still using my unported factory 2g exh manifold and o2 housing though, but that shouldnt matter for this. I still have to put my injectors and wire the AFC up then tune it, but I was expecting a pretty good jump in power just popping the turbo on at 14psi. Should I be expecting this w/o a tune? Here are the following mods:

fp big28
walbro 255lph HP pump
Dave brode upper i/c pipe
1g bov
joe p mbc@14psi
kn with maf adapter plate
full 3inch turbo back exhaust w/o cat

this is on a 2g gst 5 speed.

thanks

 

[moliver]

Until you tune it, your bigger turbo wont help much at all

 

[slickster]

Once tuned you will notice the pull difference....it is very obvious.

 

[ozzeran]

okie dokie, so once tuned it will do its thing. I'll keep the mbc turned all the way down and not chance shit till then.

 

[Rick4g63]

To realized the ful potential of that turbo, you should:
-Install a fmic
-Install a greddy bov
-hard I/C piping from turbo to throttle body.
-A boost, EGT and A/F ratio gauge is a must
- Evo O2 sensor housing and manifold.

 

[ICU812]

I just installed a ported Fpbig28 in my car last week. My mods are:


1g on Brode IC pipe
RRE LICP
K&N Filter on 4" FP intake
Brand new bottom end.


I'm running 12psi on stock exhaust and my cars AWD automatic. I still noticed a big difference compared to the T25. Seems like I'm running a little rich though. I would check everything again because you should notice a difference.

 

[ozzeran]

I just installed a ported Fpbig28 in my car last week. My mods are:


1g on Brode IC pipe
RRE LICP
K&N Filter on 4" FP intake
Brand new bottom end.


I'm running 12psi on stock exhaust and my cars AWD automatic. I still noticed a big difference compared to the T25. Seems like I'm running a little rich though. I would check everything again because you should notice a difference.

yeah thats what i thought, what could i check? i've checked my hoses, dunno what else it could be.

 

[ICU812]

You could do a minor tune up or at least check your wires and plugs if you havent replaced them in awhile. Also check for a leak in the intake. I'm kind of stumped though. If you were having a problem with anyone of these your car would likely have a lumpy idle or the car would stumble.

 

[Jeff_Jeske]

When I moved from my t25 to my fpb28 I didn't notice much gain until I upped the boost. At 20psi I was flowing 12 MORE LBS/MIN on the B28 and that is about a 100WHP increase.

I have two things that may help you see big gains. First thing is the adjustable actuator. The stock actuator tends to blow open and not hold boost to redline. The adjustable one from FP allows you to hold 21PSI to redline. It also elminates the need for a boost controller.

The the second thing is a tubular O2 housing. I noticed a nice gain when I added the O2 housing.

$75 shipped for the actuator. ($99 new)
$75 shipped for the O2 housing. ($100 new)

Both items are like new and are not wear items.

[email protected]

 

[Rick4g63]

The FP t-28 can put out more than 12lbs of airflow at 20 psi.

A boost controller is necessary when running high boost levels. At full throttle you may see as high as 25 psi on full spool up and som boost spike. I would have some sort of boost controller. jmo

 

[Jeff_Jeske]

The FP t-28 can put out more than 12lbs of airflow at 20 psi.

A boost controller is necessary when running high boost levels. At full throttle you may see as high as 25 psi on full spool up and som boost spike. I would have some sort of boost controller. jmo

Um....no what I am saying is I picked up an additional 12LBS of air for a total of 36LBS on stock cams. The most I got on my T25 was 24LBS and I was running 36LBS on my FPB28.

1LB = 11CHP

No boost controller is needed if you have the adjustable wastegate. I had mine set at 20 PSI via the wastegate actuator. It was rock solid: www.jeffjeske.com/gsx.html