my car felt slower...

My car has trouble running boost over 4lbs, where as when I floor it it seems like the turbo spools and the car starts to make power but then all of a sudden it seems like the turbo locks up and stops making power.. I have been blaming it on my stock sized exhaust and the backpressure caused by it.. So i figured if I ran open downpipe I would gain alot of power.. Tonight me and a friend took off my flex pipe and I wanted to see how fast my car would be running on open downpipe.. Well it got slower, the car would still build boost but the RPMs went up just like I was NA and driving a bone stock single cam automatic.. I have no idea what the problem is, maybe it is fuel related, i dont know... but I had been thinking all along my problem was exhaust related because it seems to pull very hard at half throttle building boost but full throttle just locks up at anything over 4psi..

im getting 3" exhaust and downpipe on next week and hoping to take it to the dyno but I cannot understand why the car got slow as **** from running open downpipe..

 

my guess says boost leak somewhere, a big one. Running open downpipe increased the boost so much that it blew off a pipe, or created a leak. That's the only thing it could be, unless your check valve system is allowing the map sensor to see boost...my best guess.

 

Im running a missing link, After I put the flex pipe back on the car ran just like it did before so I didnt blow a pipe off.. Boost leak is a definate possibility, im gonna hook up my boost gauge to the vacum line directly off the intake manifold and maybe ill get a better reading.. boost leak is definitly a possibilty considering last time i had a problem with my car it was boost leak too..

 

it sound like fuel to me what u got fmu and inline fuel pump

 

Im running the 12:1 fmu with bosch inline fuel pump.. stock intank, and stock injectors.. fuel is a possibilty too, maybe at full throttle its too rich, when I pulled my plugs they looked really rich but they were healthy, ive never had any kind of knock either..

 

Is this happening in all gears? I got a greddy kit with an inline and stock injectors. . .and in fourth gear about 4k rpms. . .I bog out. . .I think your problem may be fuel. . .

 

yep it happens in all gears.. fuel is a definate possibilty.. I dont think I can afford to put it on a wide band though..


[Modified by DIRep972, 8:50 AM 1/5/2002]

 

just wondering, do you have a filter on the intake side or a sock or something.......just saying this cause when my friend had extended the turbo intake to a cold air intake and then he wrecked his car, he had to take the pipe and stuff off to get new ****, he took a sock and put it on the turbo intake cause his old filter was crushed, he thought he blew his turbo somehow because in all gears it would make like 3 lbs of boost and then at like 6000 the boost level would jump, it turned out to be the sock was to thick or something and drowning out the turbo, he put a filter on it and bam, back to normal........

 

Yeah chris, see if you have a sock in your turbo. I think I need to add a sock to my "what to buy next" list.
But yes, a restrictive air flow on the turbos intake will cause to boost less.

art

 

I think I solved my problem, turns out there was a sock stuck in my turbo...

Update: today I checked for boost leaks and all my piping seems good, I relocated the boost gauge to the vacum line coming off the intake manifold and I took out my Boost controller.. Took the car out for a spin on .3bar(wastegate spring size), my gauge was reading a steady .25bar.. would that be a boost leak? or is that just possible pressure drop through the intercooler(i have the new big *** revhard one).. anyways the car seems to haul *** on 4psi.. Seems just as fast as it did on 8psi.. This tells me there is too much back pressure in the exhaust and puts me back where i started..

Could my boost controller possibly be messing things up when I switch from 2 1/8 exhaust to open downpipe? Right now the car seems fast without a boost controller hooked up, should I leave it unhooked or should i hook it back up but just turn it all the way down.. Its the Turbo XS high performance manual boost controller..


[Modified by DIRep972, 10:52 PM 1/5/2002]

 

maybe your gauge is off...

 

its a greddy, I doubt its off..

 

hmm if u bog in a certain ger, check the gap in your plugs. dont gap them to much. about .30

 

Can I use the sock that I have stuffed in my pants?