Power and more of it
Submitted: Sunday, Feb 29, 2004 at 22:09
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Bonz (Vic)
I was just wondering what the limitations/considerations were with increasing power output from ones engine. I have heard tell that a bigger exhaust will give me more power, mate has a Defender and put a 2.5" exhaust on and Truckster has a 3" (2.5"?) one and it helped but why? Does it allow the gases to get out faster hence allowing more fuel air mixture in and a bigger bang?
If the fuel is limited on intake electronically then how do you get more power out the other end without remapping the engine management system ala D-tronic?
Its amazing what wafts thru ones mind when wandering around the Motor show...
Any clues would be good.
ThanxLife ISN'T like a box of chocolates...it's more like a jar of jalapenos.
What you do today, might burn your bum tomorrow."
Reply By: Wayne (NSW) - Monday, Mar 01, 2004 at 08:37
Monday, Mar 01, 2004 at 08:37
Bonz
The other replies have spoken about getting the air (exhaust) out .Getting the air in will also help. Fitting a
snorkel will help force air into the turbo and there fore increase torque.
I did notice an increase in torque, when driving on the sand dunes at
Stockton Beach , after the exhaust was increased to 2.5", the new exhaust had a lot of the bends taken out and all the mufflers removed.
WayneAlways Out'N About
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Reply By: ianmc - Monday, Mar 01, 2004 at 10:09
Monday, Mar 01, 2004 at 10:09
I have had a 2.5" exhaust on my Triton 2.5td for some time together with a straight thru muffler and the fitter did a great job in minimising bends.
As advised the turbo acts as something of a muffler so the noise level is only slighlty increased, low speed torque is improved a little, but top speed remains about the same but this may be due to gearing & engine characteristics I feel.
It cost me $250 but the pipe used was thin & probably resonates a bit. I would go for a heavy guage pipe & muffler if possible & probably greater life.
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Reply By: Member - Bradley- Monday, Mar 01, 2004 at 10:44
Monday, Mar 01, 2004 at 10:44
Best way to think of an engine is as a big air pump.. gas in / gas out. Atmospheric pressure will push gas into an engine but the exhaust stroke of the cycle has to 'push' the gas out so to speak. of course the gasses are hot and therefore expanded, so they will need to move at speed to evacuate to combustion chamber. Exhaust headers are designed to 'scavenge' the gases and help remove combusted gases from the chamber to allow for more fresh gas on the next cycle. The exhaust pipe should be of a large enough diameter and minimising any sharp bends , the bends should be mandrel bent as this does not decrease the internal diameter of the pipe and reduces frictional losses from the bend. With turbos, go for an incresed diameter from the outlet flange onwards, with an internal divider for the wastegate gases. For max power use a custom header manifold as
well ( $$) upgrade turbo etc ($$$) There is also a lot of thermodynamics involved but i'm sure as hell not going into it here. lol. Hope that didn't confuse too much.Just killin time till
easter...............go and play in the dirt, instead of workin in it......
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