Guys... Need your expert opinions and preferably experience here...
I did 2 things today to my exhaust. After doing these, I felt that it has lost significant low end to mid range torque and also responsiveness. I haven't tried high rpm. Going to try later but I have a feeling its also bad. I did 5k rpm just now and the power doesn't even come yet. I am trying to figure out which of the 2 things made me lost power.
1. I change my tertiary extractor pipe to a more free flowing one. Just a short section of about 40 cm. 4AGE blacktop has as area at the exhaust where is it squashed/tapered. All aftermarket extractors replaced this section with a smooth pipe. Some people replaced only this section because it is known to be the most restrictive part of the exhaust. Refer to picture. I used quite a standard diameter 2.3".
2. I added one more midbox. My set up now is stock extractor > midbox > midbox > s-flow muffler. Previously was extractor > midbox> muffler. I thought I can add another bullet just to silence it more since already decat. They usually recommend to replace the cat with a bullet if decat to reduce noise. But I chose a midbox instead because it can reduce more noise.
Do you guys think it's caused by the change in pipe to a free flowing one, or the addition of another midbox?
Thanks!!!
P.S - Pls do not decat. Pls do not curve me coz bugger shop removed mine without telling last time.
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UPDATE: Did a mild spirited driving with slightly high load (70-80% throttle) up to about 7000 rpm. Couldn't go full because on RON95 now. The top end power seems to be the same if not a little better. Power delivery is also smoother. Previously, the engine seems to have something stucking up its power at low revs. Once reach ~5000 rpm, there is like a sudden release and I feel the "push". Now, the push is a bit gentle and spread out over time. The transition is smooth. It takes about 2 secs for the power to build up instead of a sudden release of power.
Another observation... Significantly reduced knocking even using RON95!!! Previously, I could go more than 50% throttle and dare not pass 6000 rpm when using RON95. Now there is almost no knock.
I did 2 things today to my exhaust. After doing these, I felt that it has lost significant low end to mid range torque and also responsiveness. I haven't tried high rpm. Going to try later but I have a feeling its also bad. I did 5k rpm just now and the power doesn't even come yet. I am trying to figure out which of the 2 things made me lost power.
1. I change my tertiary extractor pipe to a more free flowing one. Just a short section of about 40 cm. 4AGE blacktop has as area at the exhaust where is it squashed/tapered. All aftermarket extractors replaced this section with a smooth pipe. Some people replaced only this section because it is known to be the most restrictive part of the exhaust. Refer to picture. I used quite a standard diameter 2.3".
2. I added one more midbox. My set up now is stock extractor > midbox > midbox > s-flow muffler. Previously was extractor > midbox> muffler. I thought I can add another bullet just to silence it more since already decat. They usually recommend to replace the cat with a bullet if decat to reduce noise. But I chose a midbox instead because it can reduce more noise.
Do you guys think it's caused by the change in pipe to a free flowing one, or the addition of another midbox?
Thanks!!!
P.S - Pls do not decat. Pls do not curve me coz bugger shop removed mine without telling last time.
**********************************************************************************
UPDATE: Did a mild spirited driving with slightly high load (70-80% throttle) up to about 7000 rpm. Couldn't go full because on RON95 now. The top end power seems to be the same if not a little better. Power delivery is also smoother. Previously, the engine seems to have something stucking up its power at low revs. Once reach ~5000 rpm, there is like a sudden release and I feel the "push". Now, the push is a bit gentle and spread out over time. The transition is smooth. It takes about 2 secs for the power to build up instead of a sudden release of power.
Another observation... Significantly reduced knocking even using RON95!!! Previously, I could go more than 50% throttle and dare not pass 6000 rpm when using RON95. Now there is almost no knock.
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