adjustable fpr's

[onehot951]

at this point i only have stage 2 chips, a lindsey boost enhancer, and a k&N air filter. would an adjustable fpr make a difference at all in performance or simply open doors to future upgrades? the car pulls hard but it does suffer from LOTS of turbo lag even with the boost enhancer. i dont get full power till around 4,000 rpm. just trying to speed things up a little and now im sitting on a little bit of money saying the xj-s i was going to buy fell through. any thoughts

[nize]

it sounds like one of those cases where if you don't know what it does, you probably don't need it.

what do you plan to accomplish with an adjustable fpr?

do you have a wideband sensor to make use of fpr adjustments?

[onehot951]

basically just trying to get a little more power out of the car, wasnt sure if the stock fpr was limiting anything with the chips being in the car.

[nize]

adjustable FPR is usually for custom tuning AFR, which requires a wideband sensor. chips are already pre-tuned.

what stage2 chips do you have? is the turbo stock? it sounds strange you don't get full boost until 4krpm when the stock turbo on an un-chipped car gets full boost well before 3krpm.

maybe troubleshoot the boost lag issue first.

[onehot951]

i have the stage 2 autothority chips. any idea what would cause the turbo to have quite a bit more lag than normal? i noticed a few years ago my friends 86 spooled quicker but didnt punch as hard. you can see from the video i posted which you responded too that the boost guage indicates 2 bars right at 4,000 rpm and thats when things get exciting but almost never before then

[nize]

oh wait, try this test:

in 4th gear starting at 2krpm, go to full throttle and see when you get full boost.

get a video if you can.

[88BlueTSiQuest]

Clogged cat, dirty air filter, collapsed downpipe, bad wastegate and even a bad turbo can all lead to lag.

If you are looking to drop money on it, one of the best purchases you can make is an exhaust. Get rid of the cat, if you don't have smog testing, and you can really wake up a turbo car.

I've got some videos of how my LR 3" system with Magnaflow muffler and no cat sounds:
http://www.youtube.com/user/jnjholding

[onehot951]

i do the the 4th gear test and post the video tomorrow. is there a way to clean the cat out? the air filter was cleaned not all that long ago (K&N).

[nize]

easiest way to 'clean' the cat is to remove the exhaust, and then use a long steel rod to knock the inside clogs out of the cat section.

[onehot951]

lol yep, im not sure if thats cleaning or hollowing it out. either way its up for emissions this year and it did pass 2 years. ago. how old do these cars have to be before we dont have to do emissions anymore?

[nize]

as long as your car is running properly, you should pass emissions easily without a cat.

i think the age requirement is 30 years before the car is exempt. it could be 25 years, i forget.

[onehot951]

this is the graph that lindsey racing uses to show how there boost enhancer changes the power curve, and im peaking right where they say it should, but the way my car is building power is nothing like that graph at all. it slowly builds and then shortly before 4k all hell breaks loose . possibly a vacuum line

[onehot951]

Ok this was on an interstate. short video, but the car is in 4th at around 2500rpm. watch the boost guage as its pretty much at full boost around 3 with my foot all the way on the floor at 2500

http://www.youtube.com/watch?v=ZVDtP2FSv2A

[nize]

that seems about right for a car with an LBE and a stock turbo+wg.

[onehot951]

oh good i was worried that something was failing. i was surprised to see it build boost almost immediatly from 2500 rpm and to be fully on by 3. usually i just down shift but that test proves the boost does fully come on well before 4,000

thanks nize