i have installed it per directions, and it is weird. between shift, i let off gas, shift and floor it(set at 10psi) and it hits 12-13 for a second, then goes to 10. is this normal?

second, i have a exhaust sound, it has always made it(since turbo swap). again between shifts, under no boost, just easy driving, it makes a loud popping sound. is this normal. i have full 2 1/2 turbo back w/test pipe. thanks

Brian

You are boost spiking. How is your wastegate line run?

my line is stock, i assume i hooked it up correctly, it t's off the bov and goes to ...hum, im not sure, but i will look. i think it also did it without the boost controller, so that might be my problem. just for laughs, where is the wastegate suppost to plug into(vaccum line)

Brian

It should be plugged before the trottle body. If you sway you T'd off the bypass valve vaccum line, that's not ok. The wastegate must "see" the pressure before the trottle plate.

You should see a 1/4" nipple somewhere near the U pipe between the intercooler and the TB, or there's a tiny metal pipe getting out of the intercooler (if you're top mounted).

The first boost controller I tried was also boot spiking. It went to 11 then 9... Change it for a turbosmart mbc and it's better. Don't think cheap.

That's not true. A lot of people have the wastegate line plugged straight into the intake manifold. The most important aspect is the wastegate must see how much pressure is going into the motor. If you have no vacuum leaks, putting the wastegate line right before or after the throttle plate should yield exactly the same results. T'ing off the BOV I do not agree with. This takes away some of the pressure from the wastegate, making it open later, and when it finally catches up, it makes the boost go back down. You need a separate independent source for the wastegate. The BOV and boost gauge can be T'ed off each other however.

The Hallman MBC is not a crappy boost controller. It is among the best MBC's.

thanks guys, the reason we did my vaccum lines this way is there was an uneven # of them with places to hook them up, so we figured it was right. i had a friend of mine help me(dsm guys, who knows his turbos) and he said thats the way it is on there cars, and MIGHT be the same for ours.

if i plug the wastegate into the intercooler u, where does the plug on the intake pipe right past the maf go? i might have my vaccum all wrong, hince my 14.2@96 at stock boost on a t25. thanks guys.

Brian

Tuned,
Your vac lines sound OK. The boost spikes up a pound or so and then sets right back down right? That's normal.

Your 14.2 is good for your mods. What were you expecting? No cams right? I'm asking 'cause I got the same mods and times as you. If I'm slacking, I wan't to know ;)

Cheers,
Charlie :)

my vac is 18, is this correct for det? we will see what 10psi will do at the track tomorrow on those same shity rsa's:rolleyes: hope to break the 13's, if not, then i guess i will try 12psi.

thanks guys.

Brian

does anyone elses car make that backfire sound between shifts? i was wondering if it is normal. another board member and i were talking and he said he thinks its the absence of air in the pipes at closed throttle, the air is backtracking to fill the void.

Brian

18 in/HG of vacuum is fine for stock cams. 20 is ideal. The backfire sound is perfectly normal, especially with no cat or a big exhaust.

I also think that when you close the throttle it is rich fo a split second and excess gas ignites in the exhaust.