Thread: exhausting issues

"OFFROAD however the stock exhaust was best. Withought the back pressure from the exhaust going downhill in an auto is dangerous,"

I'm sorry,, What??

Originally Posted by Pedro_The_Swift

"OFFROAD however the stock exhaust was best. Withought the back pressure from the exhaust going downhill in an auto is dangerous,"

I'm sorry,, What??

Quick story, went up a steep hill in wombat in L1 and had to come back down. Stock exhaust had no problems, super low from idle. Same hill week or 2 later with the straight pipe went up in L1, done the turn and started the descent and thought i was going to die basically it felt like i was in N
It makes a massive difference in low range descents withought the aid of the compression brakes the trans is useless untill it begins to overun.
Even when coasting on the freeway with the straight pipe, if you take your foot off the throttle the revs drop much lower basically idle. With the mufflers the trans overruns like it should instead of just like free spinning.
Hard to explain, take your pipes off and go for a spin

'Even when coasting on the freeway with the straight pipe, if you take your foot off the throttle the revs drop much lower basically idle."

Well that bits not right,, assuming the tranny is locked up, the gearbox wont unlock (or disengage) until below 40kph.

and in low 1st what you are describing is disengagment,, even unlocked there is still a connection between engine and wheels,,

was HDC used?

Originally Posted by Pedro_The_Swift

.....
Well that bits not right,, assuming the tranny is locked up, the gearbox wont unlock (or disengage) until below 40kph.

and in low 1st what you are describing is disengagment,, even unlocked there is still a connection between engine and wheels,,

was HDC used?

Wrong D!
You're thinking D2 .... Jim's talking D1 speak!

Oooops,,, My apologies to all...

Originally Posted by LRJim

Quick story, went up a steep hill in wombat in L1 and had to come back down. Stock exhaust had no problems, super low from idle. Same hill week or 2 later with the straight pipe went up in L1, done the turn and started the descent and thought i was going to die basically it felt like i was in N
It makes a massive difference in low range descents withought the aid of the compression brakes the trans is useless untill it begins to overun.
Even when coasting on the freeway with the straight pipe, if you take your foot off the throttle the revs drop much lower basically idle. With the mufflers the trans overruns like it should instead of just like free spinning.
Hard to explain, take your pipes off and go for a spin

If your ECU sees more than a few km/h from the speed sensor it raises the idle speed. Nothing to do with pipes or the lack of them. If I was forced to own a D1/RRC V8 I would find and cut the speed sensor feed to the ECU. I installed a 14CUX onto a 110 County once without the speed input and it runs perfectly well.

I think were getting a bit technical for the point i was making.
Big pipes, no back pressure = no exhaust brakes. Low speed downhill descents 1-5kph you notice it a lot, the auto trans isnt low enough without the exhaust brakes on steep downhill descents.
I learned that by the punker effect of my brown eye

gaskets if fitted wrong way around causes leakage

Borrowed from RPIV8 site
Although it may seem obvious, which way round you fit the exhaust gaskets, it is very possible to get it wrong, We strongly suggest you check [& double check] the correct alignment as the following 2 pictures will show, getting it wrong has serious power loss implication



It's clear to see just how wrong things can be. The problem is not 'the wrong way round', but 'inside out & the wrong way round'




Surprisingly enough, exhaust blow was not a problem but power was 40% down (minimum), especially as rpm. increased.