3" to 2.5" d/p vs 2.5"d/p?
15 July 2004, 08:48 PM
#1
Scooby Regular
Thread Starter
Join Date: Aug 2002
Location: Lancashire
Posts: 570
Likes: 0
Received 0 Likes
on
0 Posts
3" - 2.5" downpipe vs 2.5" downpipe?
Hi Guy's,
I have open neck versions of both the above and am trying to figure out the relative merits of each of them before having the mota remapped. Has anyone got any info or experience regarding the differences in performance between them?
Mota is a P1 with various other mods.
thanks in advance,
Steve.
I have open neck versions of both the above and am trying to figure out the relative merits of each of them before having the mota remapped. Has anyone got any info or experience regarding the differences in performance between them?
Mota is a P1 with various other mods.
thanks in advance,
Steve.
Last edited by The TunnelMeister; 16 July 2004 at 04:27 PM.
17 July 2004, 12:51 AM
#6
If going 3" go 3" all the way - downpipe with NO drop to 2.5", and 3" centre and rear.
Then, if not getting new 3" throughout d/pipe, and choosing d/p, 3" to 2.5" may be ok for mid power motors, a bit better than 2.5" d/ps but the drop down may not help peak power. Not sure if it benefits spool up or torque, midrange etc.
What power you running looking to run? Seems 3" is best for 320/350 ish engines. #
Just passing on some comments I have had for my car setup!
Then, if not getting new 3" throughout d/pipe, and choosing d/p, 3" to 2.5" may be ok for mid power motors, a bit better than 2.5" d/ps but the drop down may not help peak power. Not sure if it benefits spool up or torque, midrange etc.
What power you running looking to run? Seems 3" is best for 320/350 ish engines. #
Just passing on some comments I have had for my car setup!
17 July 2004, 09:13 AM
#7
Scooby Regular
Thread Starter
Join Date: Aug 2002
Location: Lancashire
Posts: 570
Likes: 0
Received 0 Likes
on
0 Posts
Will do Mr Askew, thanks. 
Vulnax999, thanks for that.
Mota is already fitted with 2.5" decat centre & back, I added the 3-2.5" d/p some time ago. It increased the bhp but seemed to drop torque which I've since struggled to recover despite other mods. Looking for 310-320 lbs/ft & 330+ bhp after remap.
Not knowing what merits are claimed by the manufacturer are for the 3"-2.5" d/p I'm hoping someone on here can help.
At the moment I'm running 2.5" straight thru' and it 'seems' a little slower on spool up, but that could just be me!
Anyone else any thoughts?
cheers,
Steve.
Vulnax999, thanks for that.
Mota is already fitted with 2.5" decat centre & back, I added the 3-2.5" d/p some time ago. It increased the bhp but seemed to drop torque which I've since struggled to recover despite other mods. Looking for 310-320 lbs/ft & 330+ bhp after remap.
Not knowing what merits are claimed by the manufacturer are for the 3"-2.5" d/p I'm hoping someone on here can help.
At the moment I'm running 2.5" straight thru' and it 'seems' a little slower on spool up, but that could just be me!
Anyone else any thoughts?
cheers,
Steve.
Last edited by The TunnelMeister; 21 July 2004 at 06:11 PM.
Trending Topics
22 July 2004, 07:45 AM
#9
Former Sponsor
iTrader: (4)
Join Date: Jan 2001
Location: ECU Mapping - www.JollyGreenMonster.co.uk
Posts: 16,548
Likes: 0
Received 2 Likes
on
2 Posts
I think the strangulation mentioned for the 3" to 2.5" is a bit out dated now...
Believe over 400bhp has been run with a 3" to 2.5" downpipe and 2.5" system..
With the right turbo of course!
Simon
Believe over 400bhp has been run with a 3" to 2.5" downpipe and 2.5" system..
With the right turbo of course!
Simon
22 July 2004, 08:03 AM
#10
Scooby Regular
Thread Starter
Join Date: Aug 2002
Location: Lancashire
Posts: 570
Likes: 0
Received 0 Likes
on
0 Posts
Thanks for your input Simon, its appreciated.
Does anyone have any views about advantages of the "3-2.5"? ie does it allow faster spool up, have less initial flow resistance etc than the straight 2.5"?
Steve.
Does anyone have any views about advantages of the "3-2.5"? ie does it allow faster spool up, have less initial flow resistance etc than the straight 2.5"?
Steve.
22 July 2004, 08:05 AM
#11
Former Sponsor
iTrader: (4)
Join Date: Jan 2001
Location: ECU Mapping - www.JollyGreenMonster.co.uk
Posts: 16,548
Likes: 0
Received 2 Likes
on
2 Posts
There has been talk of the reduction to 2.5inch helps spool up but I have no proof of this and have only ever run a 3" to 2.5" and the standard downpipe on my car.
22 July 2004, 08:19 AM
#12
Scooby Regular
Thread Starter
Join Date: Aug 2002
Location: Lancashire
Posts: 570
Likes: 0
Received 0 Likes
on
0 Posts
Thanks again Simon!
I currently have a 2.5" version fitted, car is booked for remap late August and this question is niggling me. I want to make sure I have the best option fitted for next month. I've just emailed Scoobysport with the question, will let you know what they say!
cheers,
Steve.
I currently have a 2.5" version fitted, car is booked for remap late August and this question is niggling me. I want to make sure I have the best option fitted for next month. I've just emailed Scoobysport with the question, will let you know what they say!
cheers,
Steve.
22 July 2004, 08:25 AM
#13
Former Sponsor
iTrader: (4)
Join Date: Jan 2001
Location: ECU Mapping - www.JollyGreenMonster.co.uk
Posts: 16,548
Likes: 0
Received 2 Likes
on
2 Posts
You might have a long wait emailing Scoobysport..
They are in change of ownership and business etc..
I'd ring H&S (Hayward and Scott).
A 3" will release more power and if you have the money to spare then go for it but you should be able to get the power you want with the 2.5inch.
Simon
They are in change of ownership and business etc..
I'd ring H&S (Hayward and Scott).
A 3" will release more power and if you have the money to spare then go for it but you should be able to get the power you want with the 2.5inch.
Simon
Thread
Thread Starter
Forum
Replies
Last Post