Thread: Boost lost at high speeds. Help?

I watched the boost meter go from 1/4 to full and back down. I could feel the boost kick in and drop, kick in, etc. I normally never drive that fast, wanted a quick rip before winter as it is being stored. I know i need atleast headers. (saving over winter) Decent intercoolers are 1000. Wondering if a tune could fix this. (still no idea of how much KR i have)

Thanks, I'll check the bypass valve tomorrow. If it's fine, do you know where i could get it tuned? Ps. I'm not quite high in the cash area haha. I have a small feeling that once i took it to a mechanic and had him change the transmission fluid. He may of re-tuned the pcm. I think he may have metioned this, and didn't do a very well job on it if so.

Thanks alot man, i think a good tune will help alot. Too bad you didn't live in MI! haha, well i'll take a look for some people who can do a good tune. Thks for the offer, i will if im ever close.

Half of this thread doesn't make sense.

What are your plugs gapped at? When's the last time you changed the fuel filter?

I know a guy that tuned my car his shop is in sterling hts r u in the up?

Yes im in the U.p. i go to michigan technological university. plugs are gapped at .057-.060. I told them to gap it inbetween that. Im not sure if the fuel filter has been changed or not. 77k on the car all the fluids were flushed out and changed in march.

I thought the cold weather here, 30 degrees, may have affect on the boost. but i still want a tune, and a fix to this problem.

That makes sense, the pcm would read kr, and reduce the boost. As for fixing this, i have a goal of 0 kr. or as close as i can get it. So i pull more horsepower. I know i could ported the sc, get headers, or a ic. I don't want a ic becuz of price. But i heard a real good tune, could maybe fix this?

if it is from knock, then yes it could be tuned out depending on how much knock you are seeing or what your issue is. If you dont know what your issue is for sure, then how can we tell you if a tune will fix it? You need to find someone to tune your car or you need to find a way to scan to see what is actually going on. You get the most knock at the top of second gear, or going up hill. You may be boost stacking, too much knock...who knows. You have to find out for us then we can be of more help. I would recommend getting it tuned, because they can see what is going on at the same time and get rid of as much knock as possible. I have about five friends that went to tech....all mechanical engineers

PCM doesn't pull boost...it pulls TIMING. You need more flow mods. a downpipe isn't cutting a 3.4" setup. Plus...why do you need to go that fast anyways...well into 3rd gear in a GTP is what...120+?

And gap the plugs closer. Try .055"

Hmm yeah, stick with me i've been doing all these mods myself, so im still learning.. always been into the more stereo side. Anyways you mentioned you have friends from tech? Interesting haha, I'm in the civil department though. I'm pretty sure it must be knock, but your right as i will need to scan it. Drive around with someone with a scanner, but i can't seem to find anyone near by that is useful. Not many people into modding. I'm not sure where i can get this tuned though, that's the main problem. Not sure if i want to spend money on tuning software if i dont' have too. Also I read, if i replace the headers, this will fix flow problems, and is probably the best exhaust mod.

Originally Posted by pizzi22

Hmm yeah, stick with me i've been doing all these mods myself, so im still learning.. always been into the more stereo side. Anyways you mentioned you have friends from tech? Interesting haha, I'm in the civil department though. I'm pretty sure it must be knock, but your right as i will need to scan it. Drive around with someone with a scanner, but i can't seem to find anyone near by that is useful. Not many people into modding. I'm not sure where i can get this tuned though, that's the main problem. Not sure if i want to spend money on tuning software if i dont' have too. Also I read, if i replace the headers, this will fix flow problems, and is probably the best exhaust mod.

yes, headers will help the exhaust flow the best as it replaces the manifolds and the u bend. You will need to get a tune for this as well to run safely. I dont know anyone currently at tech, they have all graduated several years back.

Hmm, so i still will need a tune, can you tune the DHP with hp tuner software? or do i need a power tuner. i hear different things about it being locked and such. I'd rather go on a small road trip (there always fun) and get it tuned right by someone who knows how, if i can find someone within reasonable distance (within a few hundred miles)