Notices
Drivetrain Gearbox, Diffs & Driveshafts etc

2 1/2 inch exhaust system power limit?

Thread Tools
 
Search this Thread
 
Old 23 January 2004, 08:48 PM
  #1  
Tone Loc
Scooby Regular
Thread Starter
iTrader: (1)
 
Tone Loc's Avatar
 
Join Date: Mar 2000
Location: UK
Posts: 5,166
Likes: 0
Received 0 Likes on 0 Posts
Question

I currently have a 3 inch downpipe which tapers to mate with a 2 1/2 inch centre section and backbox (Scoobysport). I'm just in the process of getting a FMIC and 550 injectors (link ecu) and im just woundering if i should be thinking about changing the exhaust. To be honest 350bhp would be all im looking for (i want to try to keep my gearbox in one piece ). So will my exhaust happer this... my initial thoughts are i should be ok at the power level i want. What do you think and what have other people achieved with this size of exhaust?

Tony.
Old 23 January 2004, 09:32 PM
  #2  
Pavlo
Scooby Regular
 
Pavlo's Avatar
 
Join Date: May 2002
Location: home
Posts: 6,316
Likes: 0
Received 2 Likes on 2 Posts
Post

Leave it the way it is.

Very little difference until you start hitting over 350hp. John banks can testify. Although a good 2.5" will be better than a bad 3" if you get what I mean.

Spend the money on roller/mapping time to get the best from the car.

Paul
Old 23 January 2004, 09:35 PM
  #3  
Tone Loc
Scooby Regular
Thread Starter
iTrader: (1)
 
Tone Loc's Avatar
 
Join Date: Mar 2000
Location: UK
Posts: 5,166
Likes: 0
Received 0 Likes on 0 Posts
Post

Cheers Paul.... that's the answer i was expecting/hoping for

Tony.
Old 23 January 2004, 10:41 PM
  #4  
AndrewC
Scooby Regular
 
AndrewC's Avatar
 
Join Date: Jul 2000
Location: Lancashire
Posts: 2,209
Likes: 0
Received 0 Likes on 0 Posts
Post


That's why I'm changing mine...doh!
Old 23 January 2004, 10:44 PM
  #5  
Tone Loc
Scooby Regular
Thread Starter
iTrader: (1)
 
Tone Loc's Avatar
 
Join Date: Mar 2000
Location: UK
Posts: 5,166
Likes: 0
Received 0 Likes on 0 Posts
Post

What power are you after Andrew? Im guessing if your sticking to your standard MAP sensor (so 1.4 bar limit with the Link) that 350bhp would be an achievement. However you may be planning to run more boost??? If not won't the system you have now be ok? Im certainly not keen on spending another £600 on the exhaust.

Tony.
Old 23 January 2004, 11:06 PM
  #6  
AndrewC
Scooby Regular
 
AndrewC's Avatar
 
Join Date: Jul 2000
Location: Lancashire
Posts: 2,209
Likes: 0
Received 0 Likes on 0 Posts
Post


I've done another deal!

Later map sensor is good for 1.55bar according to Bob, but I'm not going that far, like I'm not changing the ECU, not getting an FMIC...
Old 24 January 2004, 12:16 AM
  #7  
Bob Rawle
Ecu Specialist
 
Bob Rawle's Avatar
 
Join Date: Mar 1999
Location: Swindon
Posts: 3,938
Likes: 0
Received 1 Like on 1 Post
Post

Confirming later map sensor (MY97 on)reads to 1.55 bar with a link ... or 1.8 bar with a Motec/Gems.
Earlier, up to MY96, reads to 1.2 bar only.

cheers

bob
Old 24 January 2004, 01:09 AM
  #8  
john banks
Scooby Regular
 
john banks's Avatar
 
Join Date: Nov 2000
Location: 32 cylinders and many cats
Posts: 18,658
Likes: 0
Received 1 Like on 1 Post
Post

I could plot my 3" results over the top of the 3 to 2.5" results done on the same day. This was at about 320 WHP on Delta Dash - about 360-400 BHP depending on the dyno.

I'm quite tempted to go back to something smaller now Loss of 10 BHP for cutting out all the noise would not bother me. Silent torque is good fun and a little more subtle
Old 24 January 2004, 01:37 PM
  #9  
Tone Loc
Scooby Regular
Thread Starter
iTrader: (1)
 
Tone Loc's Avatar
 
Join Date: Mar 2000
Location: UK
Posts: 5,166
Likes: 0
Received 0 Likes on 0 Posts
Post

Cheers John, definately stay as i am then . For 10bhp or so i'd rather keep the £600 in my pocket.

Andrew... i thought that with the standard sensor the Link load rows only went up to 240kPa (even if the sensor goes over that). I know the sensor can do more (as Bob said) as i used the later one on my car with the scoobyecu. Guess if you stick with the standard sensor and run 1.5 bar then it will just use the same fuel/ignition values as for 1.4 bar.... not much of a problem. But then again if you do get the TD06 you could get away with running far less boost for the power you want anyway .

Tony.
Old 24 January 2004, 08:38 PM
  #10  
ustolemyname??stevieturbo
Scooby Regular
iTrader: (1)
 
ustolemyname??stevieturbo's Avatar
 
Join Date: Mar 2002
Location: Norn Iron
Posts: 2,786
Likes: 0
Received 0 Likes on 0 Posts
Post

So would the older link ecu benefit or be able to use a later map sensor to allow it to read closer to 250kpa ??
Old 24 January 2004, 10:42 PM
  #11  
Tone Loc
Scooby Regular
Thread Starter
iTrader: (1)
 
Tone Loc's Avatar
 
Join Date: Mar 2000
Location: UK
Posts: 5,166
Likes: 0
Received 0 Likes on 0 Posts
Post

I'd say no. The map sensors have very different characteristics. The early one reads 2.6volts at atmospheric while the later is 2.3volts. The gradient of the graphs are also different .

If the early sensor could read up to 5volts you'd get about 1.3 bar but mine will only go up to about 4.84volts.

Tony.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Darrell@Scoobyworx
Trader Announcements
26
30 January 2024 01:27 PM
Scott@ScoobySpares
Full Cars Breaking For Spares
61
11 January 2021 03:08 PM
BlueBlobZA
Member's Gallery
30
25 July 2016 09:14 AM
jason62
General Technical
13
21 September 2015 05:20 PM



Quick Reply: 2 1/2 inch exhaust system power limit?



All times are GMT +1. The time now is 04:42 PM.