Go back to previous topic
Forum nameTurbo/Nitrous Tech
Topic subjectBoost spikes, help!
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=65909
65909, Boost spikes, help!
Posted by EclipseRST, Feb-24-04 04:32 PM
Alright guys, tonight I went WOT in 2nd gear and went up to 7psi. I tried a couple more times with the same result. Also, for the first moments of going WOT I'm hitting lean on the A/F gauge but then it jumps to rich. I've only got the HRC stage 1 so I'm only boosting 5 psi. Why am I getting boost spikes? I've heard a restricted exhaust can cause them but I've got a 3". Help!

EDIT: Now that I think about it, it wasn't just a spike, it held at 7psi before I let off.
65910, RE: Boost spikes, help!
Posted by siueclipse, Feb-24-04 04:39 PM
Has it been very cold lately? With my fuckered setup I never run higher than 5lbs of boost in the winter simply because the air is sooooo dammmnnnn cold, it can through off boost and air/fuel.
65911, RE: Boost spikes, help!
Posted by EclipseRST, Feb-24-04 04:52 PM
It's 31 degrees out right now. But I was fine when it was colder.

EDIT: I cleaned the grease and dirt off the wastegate arm. Should I only be able to push it down about a millimeter or so?

Also, it doesn't really feel like I'm going any faster. I just see boost build up. Then again I let off pretty quickly so I'm not sure if I'm giving it time to feel it.
65926, RE: Boost spikes, help!
Posted by etx, Feb-25-04 04:26 AM
Hrc kit with the internally gated 16g right? Make sure your vac lines are not pinched and that the actuator is getting a good signal from the intake manifold.
65936, RE: Boost spikes, help!
Posted by EclipseRST, Feb-25-04 05:33 AM
Originally posted by etx
Hrc kit with the internally gated 16g right? Make sure your vac lines are not pinched and that the actuator is getting a good signal from the intake manifold.



Yeah HRC 16G. All the lines seem fine. I'll post pics tonight, maybe you guys can give me more ideas.
65958, RE: Boost spikes, help!
Posted by EclipseRST, Feb-25-04 07:56 AM
Would anybody like to do me a huge favor and take pics of all the lines I could check? I'm a visual learner and during the turbo install I was under the car doing the downpipe while my friend did all the lines for the turbo so I'm not familiar with them. Points to anybody who can provide pics or links to pics and/or lots of details.
65968, RE: Boost spikes, help!
Posted by EclipseRST, Feb-25-04 11:46 AM
Arrrgh! I checked the lines and the connections all seemed fine. I'll take it for another test drive in a little bit.

What are the chances that a 1 year old turbo would have a wastegate go out already? I hope my wg isn't fucked.
65969, RE: Boost spikes, help!
Posted by turbo8u, Feb-25-04 12:07 PM
Originally posted by EclipseRST
Arrrgh! I checked the lines and the connections all seemed fine. I'll take it for another test drive in a little bit. What are the chances that a 1 year old turbo would have a wastegate go out already? I hope my wg isn't fucked.


it'd be fucked if it didnt even open, boost spike to unlimited boost...sounds to me like you might need to adjust the vac lines around a bit....wheres the vac source for the actuator go to? to the turbo? no t off's?



_________
96 talon esi-t
san clemente, ca


as needles of ice
are the ill winds' talons
the coldest of shadows
they seep unto the bone

65970, RE: Boost spikes, help!
Posted by EclipseRST, Feb-25-04 01:07 PM
That's the thing. I tried it again tonight and I didn't quite let off at 7psi and kept going a bit longer and it seemed to still be climbing. It would stay at 5 psi for a second and then start climbing. I'd like to see if it actually would keep going so I could see if it is the wastegate that wouldn't open but I'm afraid to keep testing it and seeing how far it will go in fear of blowing the motor. I've just been letting off at 7psi.

This fucking sucks. The turbo is a year old, so how could the wastegate already be going out?
65986, RE: Boost spikes, help!
Posted by ner947, Feb-25-04 05:41 PM
i've had the best luck with wastegate vacuum lines as SHORT as possible, running directly from the compressor housing to the wastegate actuator, with a good electronic boost controller inbetween the two. the way i see it, some engineer put that little port on the compressor housing there for a good reason.

this forced me to do a few things, to get the most out of my setup:

1. to not be lazy and spend a good hour or so on the highway playing with numbers in my PRofec-B, until everything was perfectly stable and i decent boost response
2. to get rid of ALL boost leaks in an effort to get the least pressure loss between the compressor and the head... this can be a PITA, but it's worth it - you'll be making more power with less boost! more efficiency, reduced loss!
3. less vacuum hose running everywhere, prone to be melted or crimped on something
65991, RE: Boost spikes, help!
Posted by EclipseRST, Feb-25-04 06:33 PM
I'm beginning to wonder if SIU was right. It could be the weather. There's supposed to be some 50+ degree days coming up. I'll see how it does then.

BTW - I was planning on buying a MBC soon since I'm upgrading to a stage 2. Would this help with my problem?
66000, RE: Boost spikes, help!
Posted by thegame, Feb-26-04 01:27 AM
Im gonna blame it on the weather too. Mine car does the same thing, even with the mbc. Oh well...


New/More Mods Comming... New 1/4 Times In March/April
66047, RE: Boost spikes, help!
Posted by EclipseRST, Feb-26-04 04:15 PM
Alright, it's 34 degrees out, and pretty chilly. I got to 8psi tonight before I had to shift. If my wastegate was bad wouldn't I boost really high since there's no restriction? If it's just the cold air then does it make sense to boost about 2 psi more than my regular 6?

EDIT: Also my fuel pressure gauge (blinky one) still reads rich when I'm boosting. It's in full green LEDs.
66053, RE: Boost spikes, help!
Posted by Ryan_Hes, Feb-26-04 10:17 PM
Regardless of any techincal solution....cars just do some fucked up things when it gets cold....lol
66067, RE: Boost spikes, help!
Posted by EclipseRST, Feb-27-04 06:11 AM
I really hope you guys are right. I don't want to have to get a new turbo. It's 48 degrees out right now. I might go try again. I'm just surprised my A/F readings are normal for having a non-interooled 8psi being thrown into the cylinders.