SS VF Series 2 : Stock vs Tune/OTR power

[Emco]

for the LS3 just go the 1-7/8 headers, all stock LS heads are exhaust restricted so need to get it out, will help over whole rpm range

I was thinking of 1 7/8 , tuners I have spoken to recommend 1 3/4 as I'm not putting a cam or forced induction.
Apparently (as I have heard) 1 7/8 actually hurts performance and only gives U higher hp on the dyno (not saying it's true but what I have heard) .
Project VF2 was quicker in 1/4 with 1 3/4 and better 0-60ft .

 

[panhead]

I was thinking of 1 7/8 , tuners I have spoken to recommend 1 3/4 as I'm not putting a cam or forced induction.
Apparently (as I have heard) 1 7/8 actually hurts performance and only gives U higher hp on the dyno (not saying it's true but what I have heard) .
Project VF2 was quicker in 1/4 with 1 3/4 and better 0-60ft .

You won't notice any low down loss from the seat of the pants.

As a side note, Sam's Performance has always fitted 1 7/8 headers to my engines.





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[Emco]

You won't notice any low down loss from the seat of the pants.

As a side note, Sam's Performance has always fitted 1 7/8 headers to my engines.





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One of the places that I haven't discussed headers with yet,
1 7/8 for more power

 

[07GTS]

good video here showing the differences

LS Exhaust Comparison Gold! HSV Headers vs Aftermarket Tri-Y's & 4-1's. What would you choose?

Well this is GOLD! Answers MANY questions about HSV and aftermarket Tri-Y vs 4-1 headers, header primary tube sizes and 2.5" or 3" exhaust cat-back systems for the LS3, by pitting them against each other back-to-back on a dyno for an objective comparison. An oldie but a goodie it seems. Well...

forums.justcommodores.com.au

 

[abuch47]

miniscule differences

 

[Strattos]

Also, how did other people's cars sound after a OCR/Tune?

Mine seems quiet. There is less overun/pop from the exhaust which makes it sound more subdued. I also expected more noise from the OCR.

Pop/overun is mainly in the tune (from my understanding - not an expert ). I had my car tuned by the same place as you and couldn't fault them. Personally, I wanted less pop and crackle, which is what I got in my tune. And based on some earlier posts in this thread (Eternity's post - correct me if I'm wrong mate) their dyno seems pretty consistent. I got around the same as Eternity with the same mods.

 

[Emco]

Vf2 ssvr manual After OTR , 1 3/4 long tube pacemakers, high flow 100cell cats, 2.5 inch hsv midsection with stock bimodal mine managed 306rwkw with 702 nm of torque.

Feels great love how it drives.. it's got that dirty V8 sound when you open it up
In terms of baseline I didn't get a chance to see my first few pulls on dyno I was outside on phone and I missed I would say tho approx 240rwkw

 

[EternityDre]

Vf2 ssvr manual After OTR , 1 3/4 long tube pacemakers, high flow 100cell cats, 2.5 inch hsv midsection with stock bimodal mine managed 306rwkw with 702 nm of torque.

Feels great love how it drives.. it's got that dirty V8 sound when you open it up
In terms of baseline I didn't get a chance to see my first few pulls on dyno I was outside on phone and I missed I would say tho approx 240rwkw

Sounds spot on for a LS3 that's run in with those mods. Welcome to the club

 

[Ron Burgundy]

How would LS3 run with VCM and OTR ? I am aware that it sometimes throws warning light, but what is this error ?
Is the car running crap/lean ?
Anyone ran with OTR only without a tune ?
Would this negatively affect the engine?

 

[07GTS]

How would LS3 run with VCM and OTR ? I am aware that it sometimes throws warning light, but what is this error ?
Is the car running crap/lean ?
Anyone ran with OTR only without a tune ?
Would this negatively affect the engine?

if it does throw a code it usually that the maf or map has gone over a set airflow target against an rpm point, it dosnt cause any issues unless it goes into limp mode but usually its just the ecu recognizing a change in airflow which could be bad for the engine but it dosnt know so it just shows a code to get looked at, usually that test is disabled so it wont affect it after decent mods, the ls3 may have a higher set point as not all see the code