a few months ago i did some vagcom logs of my power and torque, i have since had my broken turbo replaced and a supposedly uprated manifold fitted so now its all up and running like it should be i have done some more vagcom logs expecting to see a small increase in power and/or torque but instead i have the opposite.

i am down by about 20bhp and although making the same peak torque figures its making them about 500rpm later. i have changed back to the standard airbox and the torque has almost returned to the old figures and gained about 5bhp so still behind.

the car has the following mods:-

ATP exhaust manifold

blueflame exhaust system including sports cat

samco turbo inlet pipe

FMIC

samco pipe from IC to throttle body

uprated clutch

jabba remap

jabba boost controller

G60 flywheel

slightly lost by this and a bit disappointed too :(

only things i can think to check now are spark plug gap really although they have been changed in the last 6 months.

btw there are no fault codes showing at the moment as they were all cleared after the turbo was changed and have not returned. yet.

Was this after the loose manifold and turbo IP fiasco?

With the more free flowing manifold you may well have lost some back pressure.

losing a touch of back pressure is fine but losing both power and torque is slightly anoying :(

Was this after the loose manifold and turbo IP fiasco?

yep, got my hands dirty today and sorted it out though

here are the logs, pretty self explanitory

here is the plot from when it was mapped(it still had the standard exhaust at this point).

Have you logged boost pressure at all Ben?

Was the 2nd hand turbo a known good item?

the previous owner said he had no problems with it, it seems to boost fine but will try and log actual boost Vs requested boost

had to pop out so took along my technical assistant

we did some logs of the air mass meter and requested Vs actual boost.

air mass:

See... i told you all that the standard air box is better

Hope it all gets sorted soon.

have you done logs before all this work or are you relying on figures from your remap printout?

in his first 2 graphs, the blue line is from vagcom, post remap but pre replacement turbo/new manifold. the problem is that the power/torque seem to be lower now that he's had the turbo replaced and a new manifold fitted than before.

don't really know why he's posted the jabba graph...:confused:

He's done logs before the work and I know he's got some from earlier this year too.

if you read the titles on the graphs you will see what each line represents

has the manifold you've installed got larger ports?? if it has it would account for having less power all the way through the rev range, because if the ports are bigger the speed of the gas flowing through it is less so therefore gives the turbo a smaller shove as it goes through.

has the manifold you've installed got larger ports?? if it has it would account for having less power all the way through the rev range, because if the ports are bigger the speed of the gas flowing through it is less so therefore gives the turbo a smaller shove as it goes through.

if anything, wouldn't that just make the turbo spool up a little slower? but peak power should still be the same?

:confused:

if anything' date=' wouldn't that just make the turbo spool up a little slower? but peak power should still be the same?

:confused:[/quote']

possibly, but bear in mind that if the ports are larger the pressure gas flowing through is also less so it is possible that the boost pressure may also be affected.

left to it's own devices, wouldn't the turbo simply spin and spin until it produced as much boost as it physically could but is prevented from doing so by the wastgate opening?

don't think thats the case tom as it still has the same size hole going into the turbo, maybe it needs a tweak to the map? have had the exhaust and manifold done since mapping.

have cleaned botht he maf and the inlet manifold air temperature sensor today with contact cleaner and although now running a little smoother i'm not convinced its making any more power.

maybe not but it's a possibility, is there the same volume inside the manifold as there is on the old one?? all these factors need to be considered, the build up of carbon deposits on the old manifold could have increased the gas speed in the old manifold by restricting the ports slightly.

had another thought today. could it be my fuel pump?

another sympton i get which i just put down to a thing the car does until i experienced a different car is that if i boot it the car pulls a bit then backs off for a second then pulls as it should. could this be the fuel pump struggling to produce the required pressure?

had another thought today. could it be my fuel pump?

another sympton i get which i just put down to a thing the car does until i experienced a different car is that if i boot it the car pulls a bit then backs off for a second then pulls as it should. could this be the fuel pump struggling to produce the required pressure?

Sounds like mine did when I had a dodgy pump only mine was much more severe.

Also your boost seems a bit erratic. I've attached a boost log from when I had Revo for comparison.

And here's my boost. Again, much smoother than yours despite having been remapped by the same bloke.