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View Full Version : Boost pressure in relation to power values



pezza
31-10-2005, 11:49 AM
Morning guys and gals...

I got myself up to power engineering in uxbridge for a dyno run as a mate of mine with an evo FQ340 was having some ECU work done..

Having had a tune up with MUTT and changed back to my Airbox with K&N panel filter, I thought I would get a reading

The car sounds amazing at full pelt on the rollers, (I may post up some 10 sec clips if I find it) the auto gear changes sound smooth too!

WIth no boost controller fitted my 97 pre facelift car registered 264...

With MBC fitted and set to approx .7 bar (once needle settles) the car then registered 282Bhp... Does this sound about right? :inquisiti Has anyone else
taken any before and after power readings?

I normally run so that needle settles at about .8 to .85 max boost (Think I can go higher now I have stock airbox again) so may get another 15 min run (for free :thumbsup: ) now I have replaced zorst from cat to just before back box..

Cheers

Pezz

Quail
31-10-2005, 05:39 PM
Would it be poss to list your mods please mate? Just as a benchmark!

Wodjno
31-10-2005, 05:59 PM
0.7 Bar. ? Dos that give about a 2.5psi increase over standard.. ? :inquisiti

Standard boost figures sound good Derek, especially with the mileage on your car . :rolleyes4 /yes

bradc
31-10-2005, 07:33 PM
I remember someone saying around here that for each 1psi increase you should expect about a 7hp gain, I can't remember who it was though. Pezza, what was your standard boost?

Wodjno
31-10-2005, 07:42 PM
I remember someone saying around here that for each 1psi increase you should expect about a 7hp gain, I can't remember who it was though. Pezza, what was your standard boost?

I was told the same, but that was for a 2litre 4cyl turbo charged engine.. Not sure though, if the same values are applicable to a 2.5v6 TT. :inquisiti

pezza
31-10-2005, 07:50 PM
When I have removed the boost controller the gauge normally registers 0.5 to
0.55 bar depending on conditions...

I did not have any performance mods apart from the K&N panel filter. I did have the car tuned via that MUTT device and that adjusted some ECU parameters from what I saw...

I have a blitz analogue boost gauge so maybe a digital reading would've been more accurate but with boost controller in the needle does settle and about 0.7 maybe 0.75ish... I did not expect the result to be that high. I was also advised that the BHP value would always be approximate and even more so with the auto box etc...

zentac
31-10-2005, 07:54 PM
I remember someone saying around here that for each 1psi increase you should expect about a 7hp gain, I can't remember who it was though. Pezza, what was your standard boost?

I said something along those lines


0.53 bar which was standard on mine gave me
Boost Wheelbhp Flywheelbhp Torque
0.53 223 292 296 lb/ft
0.82 246 324 348 lb/ft

So 0.3 bar gave me 23 wbhp and 48 lb/ft torque

a few weeks later at 0.85bar with a much better fuel map I ran 291.7 wbhp and 314ft/lb, different rollers though so you cant really compare.

Ive since inproved the fuel map and upped the boost to 1.1 bar so would love to see what its like on the rollers again.

Wodjno
31-10-2005, 07:57 PM
I said something along those lines


0.53 bar which was standard on mine gave me
Boost Wheelbhp Flywheelbhp Torque
0.53 223 292 296 lb/ft
0.82 246 324 348 lb/ft

So 0.3 bar gave me 23 wbhp and 48 lb/ft torque

a few weeks later at 0.85bar with a much better fuel map I ran 291.7 wbhp and 314ft/lb, different rollers though so you cant really compare.

Ive since inproved the fuel map and upped the boost to 1.1 bar so would love to see what its like on the rollers again.

Impressive figures Richard.. /yes

Would also like to see your tyres after launching with 1.1bar :evil2: :inquisiti