Power limit of mods with VF1 SSV stock exhaust

[F1Aussie]

If the engine pipes from each bank join together at equal length, a V6 sounds like an inline 6.

Here's a V6 race engine midpipe we played around with X-pipe position and the video is what it sounds like, definitely not the typical V6 farty note.

View attachment 239637

Good info, that ecotec sounds pretty good. I think they may sound better than the alloytec engines generally?

 

[RevNev]

Good info, that ecotec sounds pretty good. I think they may sound better than the alloytec engines generally?

Headers probably help improve the note a bit with the Ecotec unlike the LFX style with one large exhaust port on each bank but the 6 cylinder "farty sound" is sequential firing one bank to the other. Inline 6's sound the same with split headers grouped 123, 456. If you leave the system separated or true dual or use H-pipes, V6's will sound farty and joining the engine pipes together at equal length removes the farty sound. If they're joined at unequal length, the farty sound is reduced but still remains.

VN to VS V8's always sound good with a single 2.5 or 3" exhaust because the RH engine pipe crossing behind the gearbox is longer than the LHS and "unequal length" where they join together and maintains a more V8 dual exhaust thump.

 

[Piano player]

Got it tuned today. It made 260.5 kw and 457.6 Nm torque @5500 rpm, Could not really get a good run before the tune due to it running lean from the VCM otr and 3" Hurricane cat back, made approx 190 to 200ish but no print out. Power increase is good, but torque seems low, but that is at the rear wheels not the engine. Transmission shifts are firmed up in manual mode only. Haven't really driven it properly yet but does feel more responsive. I know it's just a number but I am guessing that 260 kw at the wheels is about 300 ish at the engine.

 

[Piano player]

Update: Driven it properly........it's FUN Much quicker, will be interesting to see how the fuel economy is with the AFM turned off. It has always sat on 13.9L/100 average (dash readout not measured at the pump). But I didn't really buy the car for fuel economy, so it's more of an academic curiosity.

 

[lmoengnr]

Update: Driven it properly........it's FUN Much quicker, will be interesting to see how the fuel economy is with the AFM turned off. It has always sat on 13.9L/100 average (dash readout not measured at the pump). But I didn't really buy the car for fuel economy, so it's more of an academic curiosity.

Time to start putting money away for your 'rear tires' fund...

 

[Piano player]

Drives nice but there are a few little things:
I would have preferred it to have the firmed up shifts in sport mode rather than only manual tip-tronic mode.
Sometimes when taking off in first in sport mode (not manual) it hit's the rev limiter and there's a pause before it moves to second gear, kind of like it was before the tune, a firm shift straight into second rather than the pause would be better. I know they are different cars but my xr6 turbo when it was tuned to about the same power only ever hit the rev limiter if you forgot to change up in manual mode. It never did it in drive, it just shifted firmly to 2nd.

What would 457 nm of wheel torque equate to as engine torque? I googled a bit and it said about 530 nm engine torque which sounds stock to me. Surely if it now has 260 kw at the rears it should have more torque than stock?

 

[07GTS]

Drives nice but there are a few little things:
I would have preferred it to have the firmed up shifts in sport mode rather than only manual tip-tronic mode.
Sometimes when taking off in first in sport mode (not manual) it hit's the rev limiter and there's a pause before it moves to second gear, kind of like it was before the tune, a firm shift straight into second rather than the pause would be better.

What would 457 nm of wheel torque equate to as engine torque? I googled a bit and it said about 530 nm engine torque which sounds stock to me. Surely if it now has 260 kw at the rears it should have more torque than stock?

that pause going into second is prob it on the limiter so it also cuts power, tuner will have to lower the gear change rpm and or speed so it can have time to change before it hits the limiter, the more power u make the earlier it has to initiate the shift, at the some time they can firm up the shifts on the sport mode as well

 

[Piano player]

Quote: tuner will have to lower the gear change rpm and or speed so it can have time to change before it hits the limiter, the more power u make the earlier it has to initiate the shift, at the some time they can firm up the shifts on the sport mode as well

Shouldn't these things have already been done in the initial tune?

 

[Ginger Beer]

You typically lose 10-20% from drivetrain loss whixh is dependent on a few things
457 × 1.1 = 502.7
457 x 1.2 = 548.4
So...457 x 1.16 = 530.16 which backs up your googling

And don't stress about how much Holden said it had standard, that is running on an engine dyno without a transmission, accessories or emissions

Do you have a dyno print out with Kw And Nn at RPM

I assume you have a nice flat torque curve

 

[07GTS]

Shouldn't these things have already been done in the initial tune?

if it was just done on a dyno then they prob wouldnt have picked up on it, would have to be street driven to find that it needs adjusting, not sure how many places do a wot run in 1-2 its prob more a drive around to check average feel of it, they would have to do a log to see it then if it is adjust it accordingly, or even if u ask them to take say 200rpm lower in WOT shift rpm and 3kph lower in the WOT speed kph in the 1-2 shift, should fix it if thats the issue