Boost issues..

Swifty1638 · 04-07-2005

I had not had a mbc on the car, as the one before it seemed to be screwed up. So, Iwas boosting at 10 psi. Today, I got a mini butterfly valve deal from kory, that he had used before. I put it on, and boosted to 18 psi. However, I am not building past like 8 psi in first gear, and it seems as if I had to really step on it to get to the other upper half of psi..not only that, but it would boost up to 10 psi, then pause a bit, then go up towards 15 and lil past. Also, sometimes, when I drive, the turbo spools, but i don't feel that kick in the ass on power. What could be the issue?

-A. Swift

Swifty1638 · 04-07-2005

And, as far as the not feeling the kick in the ass, even though the turbo spools..That's always happened. I'll not feel any boost when i leave my house, but when I get towards cnty rd. 81, i then start to feel that kick. And, I have a remote start, so I do warm the car up every morning.

-A. Swift

Jakey · 04-07-2005

Quote:

Originally Posted by Swifty1638

I had not had a mbc on the car, as the one before it seemed to be screwed up. So, Iwas boosting at 10 psi. Today, I got a mini butterfly valve deal from kory, that he had used before. I put it on, and boosted to 18 psi. However, I am not building past like 8 psi in first gear, and it seems as if I had to really step on it to get to the other upper half of psi..not only that, but it would boost up to 10 psi, then pause a bit, then go up towards 15 and lil past. Also, sometimes, when I drive, the turbo spools, but i don't feel that kick in the ass on power. What could be the issue?

-A. Swift

Quote:

Originally Posted by JET

Please list the year of car, drivetrain type, ..... Also list any relevant mod's to the car and anything that you have already checked.

....

A//// Guy · 04-07-2005

Why not get a real MBC and see if that "valve" you are using is the problem? Also maybe your AF ratio is terible if you are switching boost up and down 8-10PSI...

Swifty1638 · 04-07-2005

Well, I am running boostingsx's car. ( 92 gsx, awd, built motor by mike, etc etc). I bought it from him. I don't have another mbc to use, but kory seemed to have no problems with it at all. I really don't know what it could be.

JiggahMan · 04-08-2005

Sounds like you're getting knock..

04-08-2005

Quote:

Originally Posted by JiggahMan

Sounds like you're getting knock..

I'd have to agree with JiggahMan on that one.

**JET** · 04-08-2005

Well, the 2 newbies seem to agree.

I would do a boost leak test. You could have a massive boost leak causing it to run rich and that will also limit your boost.

Swifty1638 · 04-08-2005

Well, It does run rich. I am waiting on mike to make me a new pipe to move the maft towards the intake. how can I perform a leakdown test? Just spray the shit with a soapy mist of water, and find the bubbles? I got on it today, and when i hit about 17 psi, the car felt and sounded as if i had hit the rev limiter. I was pretty sure i didn't though. I turned it down to 15 psi or so. I know that I want 20 or so, so what can a big 16g take? The motor is built by mike, and I am trusting this guy's work. I hope to take the car back to him, in hopes he can drill, tap, and place my egt probe for me. I am also waiting on that fuel rail from him( kory dropped off the sending unit for my gauge). Anyone have any other ideas? Those 3-4 vacuum "ports" on the top of the intake, right behind the biss screw (idler screw) are all plugged of. Basically, a hose, routed from one port, and 180'd into the next. Something tells me that that's not a good idea. I also thought the boost gauge was supposed to be tapped from there.

-A. Swift

**JET** · 04-09-2005

Those ports up there are just the EGR stuff. One is a pressure port though. Here is the boost leak tester.

http://www.vfaq.com/mods/ICtester.html

niterydr · 04-09-2005

uhh...could we get a mod's list? (so and so's car, built motor, etc) hardly lists whats done to the car, and more importantly whats missing to support additional power.

04-11-2005

I have the same problem. But I have done the boost leak test over and over and I get nothing. I don't have my air/fuel guage in yet so i can't tell if im running rich or lean. It will jump up to 15 lb's and then slowly crawl down to 12 or 13 lb's. Could it be that the stock turbo just really sucks.

04-11-2005

Quote:

Originally Posted by GODspeed1320

I have the same problem. But I have done the boost leak test over and over and I get nothing. I don't have my air/fuel guage in yet so i can't tell if im running rich or lean. It will jump up to 15 lb's and then slowly crawl down to 12 or 13 lb's. Could it be that the stock turbo just really sucks.

I also have that same problem but mine goes to 15 then down to 10 psi. It started to happen after i'd install my hks ssqv bov. I don't think that it's leaking because i'd did a boost leak test also and nothing show up.

04-11-2005

It might be that the stock waste gate spring just sucks. It all started after I did the BCS mod. Before that it would hold a solid 13 psi. Now it releases the boost right at 15 lb's and then back down to 13 lb's. I'm hoping it will all stop after I get my 550 cc's and evo 16g from forcedperformace.com.

Every paycheck is one step closer.

DSMkel · 04-11-2005

I'm glad to know I'm not the only one with boost problems.

Swifty1638 · 04-11-2005

Here's the mods list off of his for sale post:

-K&N replacment air filter
-GM mass airflow sensor (3inch)
-MAFT (new version) - suck through setup
-Big 16 G turbo, ported and polished witha 34mm wastegate flapper
-emissions removed
-2.25 inch Hard intercooler piping
-Small front mount intercooler
-2g throttle body elboe
-RC engineering 550 cc fuel injectors
-Walbro 190 lph in tank fuel pump (hardwired)
-Ported o2 housing
-New o2 sensor
-Custom built 3inch exhaust piping to a Magnaflow twin tip muffler
-Accel 8mm Spark Plug Wires
-NGK 7es Spark plugs
-Manual boost controller
-TMO dattaloging software on old laptop computer
-300 Watt power inverter (in center console)
-New Exide gel cell battery
-Kenwood CD player
-SAFC 1 - blue screen
-Autometer boost gauge
-Sunpro oil presure gauge
-blue - green - indiglo gauge faces
-Profesionally rebuilt motor (bored .020 over)
-Eagle H-beam connecting rods
-Wiseco forged race pistons (8.5:1 compresion ratio)
-ballanced rotating assembly (to 2 grams)
-New Advanced Clutch Technologies 2600 LB clutch
-New front axles from Autozone (lifetime warranty)
-New brake rotors all around
-New ceramic/metalic brake pads all around
-new oil presure sender
-all new belts
-balance shaft belt removal kit (QPR)

Nevermind the gauges, or the deck or other stuff ( I took it all out anyway) but the motor, mods with it..they are all still there. Any other ways for me to check fora boost leak? I don't wanna hafta go out and buy all this stuff to test it. Besides that, I am rather low on cash, so yea.

-A. Swift

Swifty1638 · 05-10-2005

I am going to assemble an ic pipe leak tester, like this one..
http://www.vfaq.com/mods/ICtester.html

I am running a big 16g, so I want to know what size rubber pipe and end cap to get? thanks..

-A. Swift