Just fitted Harrop otr custom tune and hsv headers and cats on my ve ssv and lost my crackle and pop

[Frosty005]

As the title states i just got my 2006 ve ssv manual back from the shop i had a harrop otr custom tune and vf series 1 hsv headers andand cats.... fitted was quit happy with the dyno results i gained 43 rwk and a 100 nm of torque....I have to say the car seems to be a bit quieter than it was and I lost most my crackles and pops i had when changing gears and de accelerating i used to love that sound so I have mixed feelings i enjoyed the sound of it before but it does seem to run smother through the rev range now and a bit more grunt in third and fourth gear. Although before when I nailed it in first and second before the tune etc It seemed to throw me back in the seat more ....after the tune it doesn't seem as if it does as much but seems smoother through the rev range and the second geary seems to spin a lot longer after the tune indicating it is producing more power / torque even though it doesn't seem to launch as hard into the seat.....has any one got any input into any of this ? Mainly why my crackles and pops have nearly disappeared .....the hsv headers and cats were only 1500 km old so the cats wouldnt be blocked and the original exhaust manifold and cats that came off had 140,000km on em.so I was expecting everything to flow better and be a slight bit louder and for the crackle and pops to be louder if anything...any input would be appreciated...thanks

 

[_R_J_K_]

What exhaust did you have before? Any mods or changes to it? Did it have a tune originally?

The popping is unburnt fuel in the exhaust, the cats act almost as a screen and catch the fuel on the way down the exhaust and stop it combusting in a way that produces that sound. If the car is tuned slightly rich and the cats are completely gutted it's super noticeable. Since you've got HSV cats, the cats are going to be 200 cell cats (although I don't think 100 cell would make a huge difference?).

 

[Frosty005]

What exhaust did you have before? Any mods or changes to it? Did it have a tune originally?

The popping is unburnt fuel in the exhaust, the cats act almost as a screen and catch the fuel on the way down the exhaust and stop it combusting in a way that produces that sound. If the car is tuned slightly rich and the cats are completely gutted it's super noticeable. Since you've got HSV cats, the cats are going to be 200 cell cats (although I don't think 100 cell would make a huge difference?).

Thanks for your reply....I only purchased the car around a month ago the guy I bought it from didn't do any mods but he said the guy before had done a tune in it. . and it originally had the old mace cold air set up the chrome looking plastic piping that went straight down to the pod filter that sat right behind the passenger fog light ....it also only had the stock ss exhaust manifold and cats before the hsv headers and cats were fitted ....when I got a power run before I got all the above fitted it only produced 214.7 rwk so I not sure if I believed the previous owner stating it had a tune before and I can't find any receipts showing it had been tuned before ....the end result after harrop otr and hsv headers and cats and tune was 257.7 rwk but seems quieter , no crackle and pops and doesn't seem to throw me back in the seat as hard in first and second but does Bigger second gearies and third and fourth gear pulls harder now ....I'm a little confused about it all but that's what's it's doing?

 

[SPEEDTRIPPER]

Thanks for your reply....I only purchased the car around a month ago the guy I bought it from didn't do any mods but he said the guy before had done a tune in it. . and it originally had the old mace cold air set up the chrome looking plastic piping that went straight down to the pod filter that sat right behind the passenger fog light ....it also only had the stock ss exhaust manifold and cats before the hsv headers and cats were fitted ....when I got a power run before I got all the above fitted it only produced 214.7 rwk so I not sure if I believed the previous owner stating it had a tune before and I can't find any receipts showing it had been tuned before ....the end result after harrop otr and hsv headers and cats and tune was 257.7 rwk but seems quieter , no crackle and pops and doesn't seem to throw me back in the seat as hard in first and second but does Bigger second gearies and third and fourth gear pulls harder now ....I'm a little confused about it all but that's what's it's doing?

If its tuned correctly it won't pop and crackle as its not dumping fuel into the exhaust, you'll probably find its better on fuel now too.

 

[Frosty005]

If its tuned correctly it won't pop and crackle as its not dumping fuel into the exhaust, you'll probably find its better on fuel now too.

thanks for the reply ....yes I've been doing a bit of googling and staring to see this may be the case in relation to fuel cut off and timing after the foot is off the gas pedal ...though early indications are pointing out a little more litres per hundred though this might of been as it was a shorter drive back home and a lot of right foot testing on the way home it was averaging around 13.5 lt per hundred 50/50 high way / city with the occasional squirt ...on the way home it was more like 17 per hundred...I'll take it out on weekend see if figures are better on a longer drive .....I've also been reading people saying you can get a safe crackle and pop tune without decrease in performance and still safe for the engine if you don't go overboard with the cackle and pop tune though it stated can be done for most cars it starting sounding like it was mainly for turbo cars ....I definitely miss the cackle on pop but if it does go better on petrol i may have to live with it or speak back to the workshop .....just thought I would get some in site / input from others so I don't sound completely out of touch with these newer type cars when I speak to the workshop....I've mostly had old school cars previous to this.....and it's been a while since I've had a decent ride..... thanks again for your reply