ian996
|
| posted on 28/9/15 at 10:54 PM |
|
|
Merge collector
Made 275bhp on the dyno today but it appears my exhaust collector is a choke point. It's a race line exhaust 4-1 so I'm surprised but
it's probably down to the bodging to get my silencer to fit and it needs repacking.
So where to get a good collector from that won't cost lots of money and any ideas on design. Will a venturi type design be beneficial.
|
|
|
|
|
Nickp
|
| posted on 29/9/15 at 06:07 AM |
|
|
What engine / spec is it and how have you come to the conclusion that the collector is holding it back? 275bhp sounds pretty impressive especially if
it's N/A 
|
|
|
snapper
|
| posted on 29/9/15 at 06:11 AM |
|
|
I had a larger collector end welded in to the original
So count off the double step from can to collector and have a tube the same diameter as the can all the way to the collector
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
|
|
|
ian996
|
| posted on 29/9/15 at 06:38 AM |
|
|
quote:
Originally posted by Nickp
What engine / spec is it and how have you come to the conclusion that the collector is holding it back? 275bhp sounds pretty impressive especially if
it's N/A
N/A Duratec
Amongst other things, main parts are:
- Omega HC pistons
- Saenz steel rods
- Raceline dry sump
- 1mm oversize Hi Port Neil Roper cylinder head
- Kent DTEC 80 cams
- RaceCo 54mm DTH bodies with 690cc injectors
- Emerald K3 ECU
- Raceline stainless 4-1 exhaust manifold and Wun-Off silencer
I think i can get slighty better port matching from bodies to head, but the tuner said the collector was a bit of a choke point.
Cam timing is spot on, rev limit is set at 9200. Might be worth recleaning the head as i when i took it for a shake down it was badly over fueling -
throttle pot was reading as stuck open so was throwing huge amounts of fuel in.
[Edited on 29/9/15 by ian996]
|
|
|
matt5964
|
| posted on 29/9/15 at 06:57 AM |
|
|
If you have the space a 4-2-1 will free it up and improve torque figures also.
Simpson exhausts will have them off the shelf.
Luego velocity XT 2.0ltr 221.3bhp 178.9lbft
|
|
|
Nickp
|
| posted on 29/9/15 at 07:07 AM |
|
|
quote:
Originally posted by ian996
quote:
Originally posted by Nickp
What engine / spec is it and how have you come to the conclusion that the collector is holding it back? 275bhp sounds pretty impressive especially if
it's N/A
N/A Duratec
Amongst other things, main parts are:
- Omega HC pistons
- Saenz steel rods
- Raceline dry sump
- 1mm oversize Hi Port Neil Roper cylinder head
- Kent DTEC 80 cams
- RaceCo 54mm DTH bodies with 690cc injectors
- Emerald K3 ECU
- Raceline stainless 4-1 exhaust manifold and Wun-Off silencer
I think i can get slighty better port matching from bodies to head, but the tuner said the collector was a bit of a choke point.
Cam timing is spot on, rev limit is set at 9200. Might be worth recleaning the head as i when i took it for a shake down it was badly over fueling -
throttle pot was reading as stuck open so was throwing huge amounts of fuel in.
[Edited on 29/9/15 by ian996]
Wow, sounds a screamer!! 
I'd do as snapper has and get a piece of pipe that matches your silencer and get that welded in place of your smaller collector outlet and see
if you get an increase.
|
|
|
ReMan
|
| posted on 29/9/15 at 07:16 AM |
|
|
9200! Nice
It couldn't be the silencer its self choking could it? Do they have a hp/flow spec?
www.plusnine.co.uk
|
|
|
ian996
|
| posted on 29/9/15 at 08:20 AM |
|
|
quote:
Originally posted by ReMan
9200! Nice
It couldn't be the silencer its self choking could it? Do they have a hp/flow spec?
I know it needs repacking, it was a bit loud when i got it started for the first time, so i checked it and its something i need to do when i get back
to the UK, so might be contributing. I think its a good call to sort out the pipe from collector to exhaust though, might be able to get that done for
not much cash.
The power band is quite high so i think a 4-1 is better suited for this setup.
Anyone know of a good place to get merge collectors made up for reasonable money? maybe a longer flowing collector with venturi type pipe to silencer.
|
|
|
mookaloid
|
| posted on 29/9/15 at 10:33 AM |
|
|
quote:
Originally posted by ian996
[
Anyone know of a good place to get merge collectors made up for reasonable money? maybe a longer flowing collector with venturi type pipe to silencer.
Yes:
CGR Automotive
"That thing you're thinking - it wont be that."
|
|
|
Oddified
|
| posted on 29/9/15 at 12:47 PM |
|
|
If it's up at 9200rpm, your better staying with 4 into 1 collector, and as said above the collector itself looks ok but get a larger outlet pipe
welded in place and then all the way to the silencer. You should be at 2.5" or larger ideally, what size is there now? (hard to tell from the
picture...).
Ian
|
|
|
907
|
| posted on 29/9/15 at 02:18 PM |
|
|
If it was mine I would chop a small amount off the 4-1 and round up the end.
Weld on a bigger link that suits the can inlet.
Please bare in mind I don't know the sizes.
Paul G
 
Description
|
|
|
Nickp
|
| posted on 29/9/15 at 03:28 PM |
|
|
^ What everyone else said then 
|
|
|
