Power limit of mods with VF1 SSV stock exhaust

[Banjo79]

I don't, I did though, but I went back to a "modified" stock air box due to higher IAT when in traffic or stagging

From me looking at my IAT reading the OTR had significantly higher reading than the modified stock box

The OTR sucked hotter air from the front of the radiator, and only really got ambient temp at higher speeds

The modified stock box now pulls air from lower down and away from the radiator

Opinions may vary

View attachment 239062

How has your stock air box actually been modified? Also off the top of your head, do you remember the rough temp difference between it and the otr intake, say at a hot idle or crawling around in traffic? As much as I don't like them, I agree that they'd cool down fast when you are up it and actually need it to be as cool as possible. I really must get around to insulating mine.

 

[Banjo79]

Just to play the Devil's advocate, I had better note that I saw this, which would imply KPM/Streetfighter is produced in Australia. I'm still not convinced the exhausts are.

 

[Ginger Beer]

How has your stock air box actually been modified? Also off the top of your head, do you remember the rough temp difference between it and the otr intake, say at a hot idle or crawling around in traffic? As much as I don't like them, I agree that they'd cool down fast when you are up it and actually need it to be as cool as possible. I really must get around to insulating mine.

Cut out the side of the box facing the guard and the front of the lower section of the box

Ummm, 10's of degrees difference IIRC, no where bear as bad as when I tested it with an exposed pod in the engine bay because I wanted to see the difference, but it was enough for me to swap back to stock

My car is a VX SS though, but the principal remains the same

 

[Banjo79]

Thanks. Let's say IAT was 20 degrees more than stock box on an NA engine, does anyone know what that would translate to in timing/hp/tq loss for the first half second, standing start, foot to the floor?

 

[VS 5.0]

@immortality did some tests many years ago on temp differences between otr and factory location.

Factory location won.

 

[wetwork65]

@immortality did some tests many years ago on temp differences between otr and factory location.

Factory location won.

For what its worth - I modified the standard Holden CAI on my VY V8 Berlina years ago, by improving the seal around the "box" and cutting the second hole. Then ran it with a thermocouple. (I had time on my hands in those days).
The air was virtually completely brought in to the engine through the headlight/wheelarch area, so that any hot air in the engine bay was now almost completely blocked.
It sounded better of course and the intake temperature only dropped by a couple of degrees.
I see that an OTR would just suck in hot air, except for at high speeds
This was street driving though, with a few spirited squirts around back roads South of Perth.
Damn - couldn't try it out much, since there were a lot of speed cameras around Perth. Probably still are.

 

[07GTS]

Thanks. Let's say IAT was 20 degrees more than stock box on an NA engine, does anyone know what that would translate to in timing/hp/tq loss for the first half second, standing start, foot to the floor?

thats where the trick lies... on a factory tune its overly safe so u can loose power just because, OR u can adjust the table to suit actual heat differences that affect knock, factory starts to remove timing about the 30c iat so on a hot summer day ur already in lower performance before u even start the engine, or as 30c iat is nothing to worry about u can raise the threshold and make no less power until say 40c or 50c, IMO there is no point removing timing for iat's if u dont need too

 

[Geoff6666]

Just for comparison.
I have an L77 ute. I put on HSV headers, cats and mid-section. Barely noticeable power increase and was still VERY quiet. I then put on Maloo rear bi-modals and it sounded much better and wasn't too loud even permanently open.
I then put on an Orssom otr and got it tuned and run it on E85. It makes 270rwkw.
Very happy with it.

 

[Piano player]

Just for comparison.
I have an L77 ute. I put on HSV headers, cats and mid-section. Barely noticeable power increase and was still VERY quiet. I then put on Maloo rear bi-modals and it sounded much better and wasn't too loud even permanently open.
I then put on an Orssom otr and got it tuned and run it on E85. It makes 270rwkw.
Very happy with it.

That's wicked Geoff, pretty good number for unopened atmo engine. I will just have 3" Hurricane mid section but stock everything else and the VCM OTR then a tune. Hopefully might make 250 rwkw's but as Ginger Beer said it will make what it makes, that isn't as important as the difference between before and after when tuned. I am also hoping that the tune will firm up transmission shifts etc.

 

[07GTS]

That's wicked Geoff, pretty good number for unopened atmo engine. I will just have 3" Hurricane mid section but stock everything else and the VCM OTR then a tune. Hopefully might make 250 rwkw's but as Ginger Beer said it will make what it makes, that isn't as important as the difference between before and after when tuned. I am also hoping that the tune will firm up transmission shifts etc.

the tuner should ask u how u want the auto as they can be changed to basically suit any driving style, u have 3 modes (keeping it simple), normal (just in drive) then shifter to the left u enter performance mode, then TUTD, each can be varied in each owns way and all also relating to torque so u can have normal shifting with light throttle and u can have the pressure increase and quicker time based on the torque u want (using the throttle) and when the shifts accrue ect, what some do is u can keep the drive as factory then just adjust the power mode so its all beefed up for spirited driving, then back to D for a factory drive again, its all alot to play with to suit your style