Discussion
angus337 said:
I also asked Clive about them a few months ago, I already have clive's decat pipe, so though they woud be a good option for me. Unfortunately not availabe yet, and the design would need modifying on the passenger side to accomodate the standard air inlet route.
My plan at the moment is to go with the ACT manifolds and sell the y piece. For the MOT I think ill try getting a couple of cheap sports cats made up to fit the ACT pipes, as i can't really justify the cost of the ACT cats for one days use a year.
Yeah, what's it with 800quid for the ACTs cats?...is that not VERY dear, or am I missing something?? My plan at the moment is to go with the ACT manifolds and sell the y piece. For the MOT I think ill try getting a couple of cheap sports cats made up to fit the ACT pipes, as i can't really justify the cost of the ACT cats for one days use a year.
Classic Chim said:
Yes, none of my out rigger pics load. Says no pic try again,,, which doesn’t work either!
I have sorted it Alun.See here.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
spitfire4v8 said:
Not quite sure what you mean about not being able to fit a catalyst, it's these I'm referring to :
https://www.facebook.com/clivefppa/photos/a.215180...
It's only me that doesn't like the subaru warble and motorway drone / pressure pulses in the cabin from the std setup then ..
He is good that CF. Soooooo nice.https://www.facebook.com/clivefppa/photos/a.215180...
It's only me that doesn't like the subaru warble and motorway drone / pressure pulses in the cabin from the std setup then ..
Strictly speaking in outright flow terms the triple is way too much even for peter's 5.5 litre 400hp monster as full power is delivered on something like 2/3rds throttle.
However the outright flow is not the only reason people fit them .. the lightning throttle response from opening 3 butterflies simultaneously is often quoted as reason enough to have it
However the outright flow is not the only reason people fit them .. the lightning throttle response from opening 3 butterflies simultaneously is often quoted as reason enough to have it
When Joolz mapped my 5.5, he commented that maximum power was achieved at less than full throttle.
Given that yours is only a 4.6, a twin throttlebody plenum would be more than enough.
Out of interest, some years ago I had a tweaked 5.0 running the standard plenum with the 72 mm throttlebody. With a bespoke camshaft and other bits and pieces it achieved about 330 BHP on SRR.
I think the twin throttlebody plenum will probably give you a quicker response but not necessarily more power unless you are using the smaller throttlebody at the moment.
Given that yours is only a 4.6, a twin throttlebody plenum would be more than enough.
Out of interest, some years ago I had a tweaked 5.0 running the standard plenum with the 72 mm throttlebody. With a bespoke camshaft and other bits and pieces it achieved about 330 BHP on SRR.
I think the twin throttlebody plenum will probably give you a quicker response but not necessarily more power unless you are using the smaller throttlebody at the moment.
The ideà of a carbon triple, or even double plenums, was born out of 'man maths'....I could have BOTH ACTs exhaust and inlet manifolds for the price of my previously interested cf equal/tuned set up.
It does sound like sticking with my 72mm plenum will more than suffice for now.......THANKS!
lol
It does sound like sticking with my 72mm plenum will more than suffice for now.......THANKS!
lolI've had a 72 mm throttle on the std plenum, ACT twin throttle and now a triple throttle plenum on my 4.3 (10.5ish cr, fairly elaborately modified heads but std sized valves, now replaced with intermediate large valves; Piper 285 cam, now replaced with TVR/Kent 885). The 72 mm is good for 2-3 bhp at best, the real gain is in the better airflow distribution over the trumpets with the carbon multithrottle options.
On a 270 bhp John Eales 4.6 (10:1 cr, 218 cam, intermediate large valves, GEMS) the twin plenum gave an additional 12 bhp on his engine dyno, which surprised Tim a bit at the time as he previously thought the bhp gains were only significant on 300 bhp+ engines. Subsequent tests gave another 2 bhp or so for the triple at a similar hp level; the triple however does improve throttle response further.
The combination of ACT exhaust manifolds, twin plenum with carbon trumpets underneath and a bigger Bosch AFM gave about 24 bhp compared to blended base and 72 mm throttle on my car, on the same dyno with the same correction factors applied to the previous run (long time ago). The real impact of the airflow mods only came to light after going to the 123tune mapped ignition, which gave another 26 hp - methinks the 120,000 mile old Lucas distributor might have been fairly worn at this point with significant timing variations as a result...
On a 270 bhp John Eales 4.6 (10:1 cr, 218 cam, intermediate large valves, GEMS) the twin plenum gave an additional 12 bhp on his engine dyno, which surprised Tim a bit at the time as he previously thought the bhp gains were only significant on 300 bhp+ engines. Subsequent tests gave another 2 bhp or so for the triple at a similar hp level; the triple however does improve throttle response further.
The combination of ACT exhaust manifolds, twin plenum with carbon trumpets underneath and a bigger Bosch AFM gave about 24 bhp compared to blended base and 72 mm throttle on my car, on the same dyno with the same correction factors applied to the previous run (long time ago). The real impact of the airflow mods only came to light after going to the 123tune mapped ignition, which gave another 26 hp - methinks the 120,000 mile old Lucas distributor might have been fairly worn at this point with significant timing variations as a result...
900T-R said:
I've had a 72 mm throttle on the std plenum, ACT twin throttle and now a triple throttle plenum on my 4.3 (10.5ish cr, fairly elaborately modified heads but std sized valves, now replaced with intermediate large valves; Piper 285 cam, now replaced with TVR/Kent 885). The 72 mm is good for 2-3 bhp at best, the real gain is in the better airflow distribution over the trumpets with the carbon multithrottle options.
On a 270 bhp John Eales 4.6 (10:1 cr, 218 cam, intermediate large valves, GEMS) the twin plenum gave an additional 12 bhp on his engine dyno, which surprised Tim a bit at the time as he previously thought the bhp gains were only significant on 300 bhp+ engines. Subsequent tests gave another 2 bhp or so for the triple at a similar hp level; the triple however does improve throttle response further.
The combination of ACT exhaust manifolds, twin plenum with carbon trumpets underneath and a bigger Bosch AFM gave about 24 bhp compared to blended base and 72 mm throttle on my car, on the same dyno with the same correction factors applied to the previous run (long time ago). The real impact of the airflow mods only came to light after going to the 123tune mapped ignition, which gave another 26 hp - methinks the 120,000 mile old Lucas distributor might have been fairly worn at this point with significant timing variations as a result...
Many thanks, an Interesting read. On a 270 bhp John Eales 4.6 (10:1 cr, 218 cam, intermediate large valves, GEMS) the twin plenum gave an additional 12 bhp on his engine dyno, which surprised Tim a bit at the time as he previously thought the bhp gains were only significant on 300 bhp+ engines. Subsequent tests gave another 2 bhp or so for the triple at a similar hp level; the triple however does improve throttle response further.
The combination of ACT exhaust manifolds, twin plenum with carbon trumpets underneath and a bigger Bosch AFM gave about 24 bhp compared to blended base and 72 mm throttle on my car, on the same dyno with the same correction factors applied to the previous run (long time ago). The real impact of the airflow mods only came to light after going to the 123tune mapped ignition, which gave another 26 hp - methinks the 120,000 mile old Lucas distributor might have been fairly worn at this point with significant timing variations as a result...
Mr Haribo said:
I have a 4.6L on a triple, and yes a double will be fine even a single with a bigger butterfly will do ! Changing from a Mark Adams Ecu to a triple and a Emerald ecu got me 15bhp on the same dyno !
But the way it spins up..... love it I’m keeping the triple
Yours is the JE alloy one, if I remember correctly?But the way it spins up..... love it I’m keeping the triple
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