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kermac
09-28-2006, 12:02 AM
I posted this question yesterday under a different heading, but didn’t get many responses.

I’m trying to find from other 1.8T owners with upgraded software (and hardware) – and a boost gauge fitted - what sort of boost they are running.

Here’s mine:

16 psi @ 3,000 rpm
20 @ 4,000
16 @ 5,000
13 @ 6,000
10 @ 7,000

The question is whether it should be falling off in this way as the revs rise (16 – 20 – 16 – 13 – 10). Some say this is normal, others say no way, the boost should fall off only slightly – if at all - as you approach the red line.

I don’t have any error messages and there’s no sign of a leak. If I went up a long enough steep hill at 4,000 rpm at WOT, it would hold 20 psi all the way. This suggests it is a software issue, not a malfunction.

I’ll get a better idea if others can let me know what their boost pattern is through the rev range.

Thanks from Down Under

The equipment? MY 2000 b5 5-speed, non-DBW, GIAC 1.4-bar chip, K04, 3” turbo-back exhaust, hi-flow cat & mufflers, GFB Diverter Valve, N75J

SeanF
09-28-2006, 05:04 AM
even a k04 cant keep up at higher RPMs...

Audigeek
09-28-2006, 09:22 AM
i spike at 22-23 psi and hold at 16psi till about 5,800rpms, then it slowly starts to taper down to about 11-13 at redline.

its not a software issue. ko3's and ko4's cannot hold that high psi to redline.

mike-2ptzero
09-28-2006, 09:33 AM
This is normal for the K03 and K04. The boost will fall off quicker and sooner in the higher rpms as you increase the max boost.

Have to remember that boost is just a reading of the increasing flow rate of compressed air from the turbo, so as the rate of increasing air flow starts to slow down the boost level will start to drop. The higher you push that boost in the lower rpms the quicker the turbo will max out and cause the flow rate to level out. So if you want to have a set boost level all the way to redline you will have to run less boost.

Kruat
09-28-2006, 03:48 PM
20-22psi peak, hold 15psi. GIAC KO4 chip and MBC.

kermac
09-28-2006, 04:06 PM
Thanks guys!

I guess this confirms it for me - Big Turbo it has to be[:D]

Emil@RENN-ART
09-28-2006, 04:21 PM
yup! our program (using the n75) actually rises all the way to red-line.. and it ends at around 22psi at red-line.

http://i21.photobucket.com/albums/b273/egostberg/MY%20A4/Emil_A4_Eliminator28RS_BOOST.jpg

kermac
09-28-2006, 04:34 PM
Originally posted by Emil@RENN-ART
[B]yup! our program (using the n75) actually rises all the way to red-line.. and it ends at around 22psi at red-line.

Hi Emil

Your advice seems different from that of the other members who've responded to my post.

I'm not familiar with your profile, but I take it you are talking about the Unitronic program? Unfortunately I don't believe we have access to that in Australia as our ecus are not compatible with US-spec ecus (someone once explained that ours have 16-bit architecture while US-spec cars have 32-bit - but I'm not sure whether that applies to all A4s from b5 through b7).

I had a long talk with the Australian GIAC agent last night - a good friend - who argued pretty much as Mike argues above that if you're going to peak at 20 psi or more, your boost is going to fall away higher up the range.

So what's Unitronic's secret? And what effect does this have on power/torque?

Thanks for your interest[:D]

ceas
09-28-2006, 05:33 PM
my a4 is pretty nasty.. I don't want to make anyone jealous here.. but I hold around 4 psi '-'

mike-2ptzero
09-28-2006, 06:05 PM
Originally posted by kermac
Hi Emil

Your advice seems different from that of the other members who've responded to my post.

I'm not familiar with your profile, but I take it you are talking about the Unitronic program? Unfortunately I don't believe we have access to that in Australia as our ecus are not compatible with US-spec ecus (someone once explained that ours have 16-bit architecture while US-spec cars have 32-bit - but I'm not sure whether that applies to all A4s from b5 through b7).

I had a long talk with the Australian GIAC agent last night - a good friend - who argued pretty much as Mike argues above that if you're going to peak at 20 psi or more, your boost is going to fall away higher up the range.

So what's Unitronic's secret? And what effect does this have on power/torque?

Thanks for your interest[:D]


That wouldn't happen to be lucas would it?

Pretty sure Emil is talking about their BT since that is what the dyno says.

quickglx
09-28-2006, 06:25 PM
pc-16, holds a steady 15-16 psi ~1800-6500 RPM.

kermac
09-28-2006, 06:37 PM
Originally posted by mike-2ptzero
That wouldn't happen to be lucas would it?

Pretty sure Emil is talking about their BT since that is what the dyno says.
Yup - Lucas Lozo the Crazy Croatian. Last time I saw his car (he lives 700 km away) he had just put his new engine on the dyno at 607 hp[hail]

Emil's figures make more sense if he's talking about a BT. I didn't pick that up in the graph.

Thanks Mike

Eurotuned_A4
09-28-2006, 06:49 PM
why dont you have lucas hook you up with a tune. it sounds and looks like he can handle it?

mike-2ptzero
09-28-2006, 11:11 PM
Originally posted by Eurotuned_A4
why dont you have lucas hook you up with a tune. it sounds and looks like he can handle it?


Lucas runs a stand alone on his car to produce that power. The last time lucas had a GIAC chip on his car was back when he was making about 400hp. I have known lucas for a pretty long time since he used to deal with juan for some parts and he is a GIAC dealer. I usually hear from here now and then when he has some things to say about his car.

kermac
09-28-2006, 11:45 PM
I thought I'd just posted this, but no sign of it anywhere. Either my computer is stuffed or it's the Alzheimer's. You get to a point where you don't care which.

Lucas thinks there's not much more to be had from the K04. I am currently negotiating with him for a BT, but there have been a few delays.

I'm hoping he can help me out within the next few weeks...

I'll be away from my computer for a few days. Catch up next week...

Eurotuned_A4
09-29-2006, 12:21 AM
well, thats a good point. anyone have pics of his car and set up? im very interested.

b00st
09-29-2006, 09:32 AM
Originally posted by quickglx
pc-16, holds a steady 15-16 psi ~1800-6500 RPM.

ummm...maybe yours. [:D]
my pc16 file hits 21-22psi and ~15 by redline.
this is in warmer weather. its now 50 degrees out and now i'm at 17-18psi.