rccks96

First post here - and I've spent the last hour searching, so please bear with me if this has been discussed many times over.

I was wondering what the effects of altitude generally are?

Oh, and I have an '03 A4 1.8tQT with 380cc injectors, GIAC FX, and Evo DV

I had it VAG'd yesterday, and my brand new MAF was reading about 140 g/s. Does this sound normal?

Also, requested boost was 2300 mbar, but i maxed at about 2000 mbar. Does this also sound normal? (If i'm not mistaken, 2000 mbar is only about 14 psi, which seems pretty weak). Shouldn't i still be hitting the requested 18 psi? I realize the power won't be the same, but I think i'd still hit 18.

Also, I'm getting some pinging, mainly in 1st and 2nd gear.

I don't know what all this adds up to, but I'm wondering if the altitude has something to do with it.

Thanks for any help you can give.

DenverNoob

what other mods are you running? exhaust, intercooler, etc?

rccks96

Just the FX, injectors and DV. No exhaust or fmic.

ar design

Is the chip tuned for 91 or 93? How much timings getting pulled?

DenverNoob

140 g/s is about right without exhaust or test pipe to help the system flow a bit. also, as far as boost goes, have you logged a/f or likewise timing correction at all?

my feelings here are on a couple of levels.

you may have a bit of a leak there in the system...are you saying you only spiked 2000mbar? i would expect to see a bit more spike, and then see it level off towards the bottom of the range. HOW you are logging and in what gear is also EVERY bit as important as what the readings are. I would be happy to plug in with you and take a peak...that is, IMO, the only way.

having said all of this, there are a few things of note for this elevation...

you wont make as much boost here...the air is less dense and the turbo works harder to compress to requested levels. this is not as much of an issue as you would think, but it is an issue none the less. likewise, because of this excess heat, you will lose power faster through the rev range than you would at sea level on the k03, this is unavoidable.

lastly, im concerned with potential timing correction and your pinging. this could very well be attributed to you using the OEM spark plugs. those things are a fine-wire type platinum...they do not dissipate heat as well as other platinums or coppers, and may be contributing to that problem. i have dealt with all of the above issues and would be happy to lend you some insight if you wish.

feel free to call if you want at 303-725-9728 and we can set up a time to log a little!

-Ted

DenverNoob

GIAC only tunes to 91.

rccks96

Thanks for all the info.

I'm actually in Salt Lake, so I don't think the altitude's as big of a problem as it is in Denver (I'm at about 4,400 feet). Oh, is this the Denver only forum? If so, sorry about that.

I don't know all the details on the boost readings, as the tuner just briefly looked at it - didn't do any data logging or anything.

Oh, and there are no boost leaks - they looked it over twice now.

Thanks for the info. on the spark plugs. Yes, they're the dealer plugs - just put new ones in about 2 months ago. Do you think putting in different ones would make a difference on the pinging? If so, what kind do you recommend?

So boosting 13/14 psi sounds normal for this altitude? (i guess i need to find out more details like you requested before you give an answer).

DenverNoob

you will need a little space. get into third gear, hold about 2000rpms, then floor it. it will take a bit for the boost to build, but you will get good logs every time. that really spools out the turbo, loads up the engine, and makes it work.

do the same for knock voltage, timing correction, a/f, boost again, MAF, then email me the logs. i doubt anything major is wrong...

plugs: go with either the really cheap way or the really expensive way.

cheap: NGK BKR7E plugs. 1 step cooler than stock, coppers. they only last about 5k miles...and their gap must be checked prior to install.

expensive: Bosch F5DP0R. 2 steps cooler than stock, but still platinum. these dont need to be gapped....they are, however, expensive. with these you may have an issue or two starting in extreme cold (i never did but i hear it isnt too uncommon) but otherwise your car will love them!

DenverNoob

GIAC tested and approved:
Siemens Deka 380cc (no longer in production)
OEM Audi TT 225 386cc injectors (bosch)
USRT Gennesis 380cc injectors

used frequently but NOT approved:
Bosch 380cc injectors

rccks96

Genesis