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.

 

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

 

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

Tony.

 

That's why I'm changing mine...doh!

 

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.

 

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...

 

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

 

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

 

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.

 

So would the older link ecu benefit or be able to use a later map sensor to allow it to read closer to 250kpa ??

 

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.