G60 boost pressure query after R/R Session?

[Jay2 0]

Been to Well Lane Turbo Centre at Batley with my 91' G60 for a rolling road session today and came away with a bit of a query.

 

The technician was a bit stumped as his boost readings were giving him a max reading of 10 which he said was more normal for a standard G60, yet the C topped out at 197bhp, which was more normal for a chipped/pulley'd engine, (which was confirmed by G-Werks last summer, although type/make of chip unknown).

 

I'm a complete numpty when it comes to boost pressure, so can anyone shed any light? Is there something a-miss somewhere? :pale:

 

The Supercharger was serviced and P/P last year.

[Rob_B 0]

must be flowing well if its making good power with low boost figures. boost pressure is only a measurement of the pressure that is built up in the inlet manifold. in theory this is almost a waste as it means that the restrictions in your cylinder intake are such that the compressed air is not being fully used.

have you had any cylinder head work done?

[junkie 0]

But the air thats entering the engine is going in pressurised so although it is the measurement of restriction its still going in at that.

 

Boost = Torque

[Supercharged 2]

Strange - you'd expect 1 Bar (14/15 PSI) to produce that power...

 

Be interesting to see the graphs inc the torque plot

 

I reckon it must have had a ported head at some point.

 

I assume it feels good to drive - at that BHP should feel similar to a VR but faster / more urgent.

[Jay2 0]

That may explain it, have got an old reciept from the 1990's listing some engine work = rebore, skimmed block, new gas flowed cylinder head, oversize pistons, different cam. 8)

 

WellLaneGraph09.JPG[/attachment:1itu8k24]

 

Hoping with a full S/S exhaust it might just get over the 200bhp mark.

[JMC 0]

Yep bingo - ported and flowed head will cause the lower boost pressure, especially if the cam has been played with before.

 

Very similar to what mine was putting out before I got the Golf G60 intercooler and had it remapped to suit. When you say oversize pistons is this a 1.9l or just an over bore? To put it into context as a 1.8 with a flowed head etc mine was making 212bhp on a very conservative RR.

 

Can't make your plot any bigger to have a look at the details though :(

[Supercharged 2]

Cool - curves look good, must be a nice drive!

[Jay2 0]

Thanks guys, clears that up. :salute:

 

JMC - Receipt is a bit basic and just states "Supply 0.50 Oversize Pistons" for about £430. Was done by a place in Wales, 'AuudioGolfHits', and have been told that the place faded away once the owner passed away in the 90's. :(

[Supercharged 2]

Can't have done a bad job if it's still making 200BHP over 10 years on!

[Z-Raddo G60 0]

wonder if there is more than g-charger work done to it to make those numbers?

[JMC 0]

Thanks guys, clears that up. :salute:

 

JMC - Receipt is a bit basic and just states "Supply 0.50 Oversize Pistons" for about £430. Was done by a place in Wales, 'AuudioGolfHits', and have been told that the place faded away once the owner passed away in the 90's. :(

 

Ah right, not a 1.9l rebore then. As Supercharged says still very good for a rebuild done 10 years ago :D

[boost monkey 0]

yeah ditto!

 

glad the cyl head thing was mentioned, as usual the monkey is about 6 hours late to the party!