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Old 1st August 2008, 00:26   #16
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Quote:
Originally Posted by Shan2nu View Post
There is some production car (not getting the name) that uses dual exhaust pipes. At low revvs the exhaust exits through one pipe designed to provide torque at low revvs but when the engine revvs increase, the exhaust is diverted to another pipe designed for high rpm torque and power.

Shan2nu
Thats a great idea. If you can have variable valve timing and variable intakes then a variable exhaust should be a logical development.

Of course it would be far too complex to implement as an aftermarket modification.
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Old 2nd August 2008, 05:04   #17
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Originally Posted by theEnd View Post
...If you can have variable valve timing and variable intakes then a variable exhaust should be a logical development...
Heres some interesting info on that topic : Honda-Tech.com: All Motor: Variable Exhaust Geometry

cya
R
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Old 2nd August 2008, 09:51   #18
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very nice information. but do our indian installers who make custom headers and exhaust follow the same engineering? do they calibrate the diameter of pipes based on the engine parameters?

can someone confirm the procedure how they make custom exhausts? any technical data available?
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Old 2nd August 2008, 15:31   #19
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Quote:
very nice information. but do our indian installers who make custom headers and exhaust follow the same engineering? do they calibrate the diameter of pipes based on the engine parameters?

can someone confirm the procedure how they make custom exhausts? any technical data available?
I seriously doubt. Most of the tuned cars in India are not dyno tested so without knowing the power and torque curves, it's just a matter of being lucky with the intake and exhaust designs.

I sometimes see the same header design on 2 engines with diff characteristics. Ofcourse any header design (with eqaul lenght pipes) will give you better performance compared to the restrictive stock system, cars usually come with. So you can't lose out with a calculated header design but it's possible that someone else with the same engine mods and a more precise header/exhaust design might find a bigger improvement in perfromance.

If we were to give all the Indian tuners the exact same car and ask them to only modify the intake/headers/exhaust, you would still see a vast diff in performance, even though everything else on the car is identical.

Shan2nu

Last edited by Shan2nu : 2nd August 2008 at 15:32.
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Old 2nd August 2008, 15:55   #20
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Shan2nu,
this could also be because all tuners in India use their own indvidual calculations which are the best according to them
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Old 30th July 2009, 18:16   #21
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Help regarding FFE

I had some queries regarding modifications on my 98 carb zen. well i have been toying with the idea of modding it for a bit more pep.

Since its a carburetted engine, what i wanted to know is that if i get a complete FFE i.e. from headers to end can will the car fail pollution tests?
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Old 30th July 2009, 18:29   #22
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No! it will not fail - just make sure that you ask the person at the PUC / Pump to lean the air/fuel mixture before he takes out the final print out. That is how i do it in the Padmini. Works like a charm enjoy.

Keep me in the loop when you get it done make sure it is loud

Last edited by planet_rocker : 30th July 2009 at 18:31.
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Old 30th July 2009, 19:34   #23
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One question, what problems can you notice if the FFE is not working properly. I fitted a FFE 6 months back and sometimes when I'm driving with half throttle, the car gives a jerk, somewhat similar to improper fuel supply. Not sure whether it is a problem with fuel pump or the FFE. But the problem started occurring after fitting the FFE. When you floor the pedal for a couple of meters, then it goes off. Any idea?
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Old 13th February 2010, 13:48   #24
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ok so is there a chance that lack of restriction or back pressure can harm your engine? as in drop compression or fry the rings?
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Old 14th February 2010, 12:58   #25
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Quote:
ok so is there a chance that lack of restriction or back pressure can harm your engine? as in drop compression or fry the rings?
No, infact it will improve engine performance since there is less obstruction for the engine to overcome.

Only drawback is that you could notice a drop in low rpm performance (which can be a prob on the highway when you wanna ovartake in top gear with 4 passengers onboard).

Shan2nu

Last edited by Shan2nu : 14th February 2010 at 13:10.
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Old 15th February 2010, 10:28   #26
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ok and the end can doesnt really make a difference at all right as long as the FFE is precise ?
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Old 15th February 2010, 12:40   #27
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The end can does make a diff. If you have a FFE and a stock restrictive end can, you wont see the full potential of the FFE.

I ran my car with headers and stock mid pipe for a few months. It was only after i fitted a performance half pipe exhaust, did i realise how much of a diff it makes.

Im still using the stock intake filter, so my engine should feel even more powerful once i upgrade to a performance one.

Shan2nu

Last edited by Shan2nu : 15th February 2010 at 12:51.
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Old 15th February 2010, 13:08   #28
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ok so does the tip or mouth size of the end can make a difference?
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Old 15th February 2010, 13:58   #29
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@ Shantanu - your car must be really loud with the Half-pipe setup? Is that your daily drive?
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Old 15th February 2010, 15:55   #30
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Half of bangalore drives with half pipes, it is not loud when u are driving sedately, but once you go pedal to metal!! All hell breaks loose!


Quote:
Originally Posted by planet_rocker View Post
@ Shantanu - your car must be really loud with the Half-pipe setup? Is that your daily drive?
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