Intercooler Muffler Delete = loss of power?

[Anonymous]

Hi guys,
I just installed a delete pipe similar to this:
http://www.mini-madness.com/madness-min ... -pipe.aspx
on my RCZ THP200..
It fits well (after some minor modifications)...
But unfortunately, I seem to have lost power between 2000 to 4000 rpm.. 1st and 2nd gear seems the same as if I didn't have the delete pipe.
The difference can be felt the most at highway speeds. i.e. speeding up from 70 to 100kmh in 5th or 6th gear.. it feel much more sluggish than before..

Can anybody help me to understand why this is happening? All things equal, a straight-through pipe should only benefit performance in some way(at most have no effect at all), and not decrease performance yes?

 

[Anonymous]

It could be the ecu thinking there is a problem and limiting power. It's like when I put a k&n filter and racing exhaust in my scimitar turbo. The power dropped by 20% because the ecu didn't know what was happening and reined in the power. Once chipped it was fine, but It might not be that. It could also be something to do with the extra power Peugeot get from the engine. The mini has less. Whatever they do to get the extra power might be something to do with it. Doubt it though :eusa-think:

 

[Anonymous]

I stand to be corrected but I suspect you have upset the airflow metering. You have to remember these engines are built to meet very exact emissions regulations and are already squeezing huge amounts of power it of very small displacement. Everything is monitoring very closely by the ECU and and changes outside the expected parameters will fault the ECU.

Its not like the old days where you could modify away to your hearts content. The engineers who design and build the cars generally know what they are doing.....

Now if you really want something to modify buy a Defender!! I have taken mine from 58BHP to over 180BHP, changed the engine from a 2.5NA to a 200TDI turbo, centre box removal and big bore exhaust from Janspeed, Turbo boost increase to 18psi. Full size Allard intercooler, reworked fuel pump etc. :lol: :lol: :lol: :lol:

 

[Anonymous]

Hmm.. both of you make sense.. so the only way to solve my problem is either
a) remove the delete pipe and revert back to stock intercooler piping
b) modify my ECU
sigh... didn't think a simple pipe could change so much..

mr shiney@ for me it was actually a choice between the Defender Puma 2.4 or a RCZ about 2 months ago... in the end it was a RCZ for me... but I've always wanted to know, what's the 0-100 timing for a 180bhp Defender? =)

 

[RCZ-Performance]

Get it re-mapped at Superchips. After put on my exhaust and installed the K&N filter, I noticed a difference in the middle of the rpm range, in the wrong direction. After the remap it was much better and now the mods I did are working as designed. As others indicated, the way this engine is built, their is not much you can do to it without having to get into the ECU.

All engines require some kind of back pressure, so what you have done is allow the exhaust to flow better, but that back pressure is not the same. So I seen many people of the years install a big and loud exhaust only to lose power.

 

[Anonymous]

Zombie, Its not exhaust. its air. It's basically a muffler that quietens the air flow when it comes out of the turbo before entering into the intercooler. All part of making the car as quiet as possible. It has a side effect that it changes the flow of the air which is accounted for in the ECU. Remove it and the fuel air map is then out of sync which produces what I suspect is an over lean condition in the mid range. Not only does it effect performance but it could also be happily burning its way through your valves.

Obiecat. I am seeing a 0-60mph of 10 seconds now which is pretty amazing for a Defender!! It was not possible to count the original 2.5NA engines 0-60 as it would not get that high!! The unmodified 200Tdi is about 17 seconds and as I said the modified is 10.

In order to get that you need massive amounts of cooling surface via the intercooler and then need to change the fuelling to feed it. In a Diesel direct infection you don't have the lean issue described above as the injection pump is linked via a vacuum tube to the fuel pump so the fuel is correct. Without modifying the fuelling you get better efficiency and more torque but not a lean situation. By changing the fuelling to match the Turbo demand you can get oodles more power out!!

 

[RCZ-Performance]

Zombie, Its not exhaust. its air. It's basically a muffler that quietens the air flow when it comes out of the turbo before entering into the intercooler. All part of making the car as quiet as possible. It has a side effect that it changes the flow of the air which is accounted for in the ECU. Remove it and the fuel air map is then out of sync which produces what I suspect is an over lean condition in the mid range. Not only does it effect performance but it could also be happily burning its way through your valves.

Ahh this is me learning more about turbos, as I come from the Supercharger world. So my apologies for that mistake and thank you for educating me :beer:

Still get it remapped

 

[Anonymous]

Yeah a remap written specifically to cope with the change in airflow would probably fix it.

I think its one of those where you start a cascade of things that become harder and harder to fix. The engine is already highly strung wringing so much power out of small unit leaves a really narrow band for after market modification without starting to do some damage.

I will leave the debate around warranty out if it though!!!

 

[Anonymous]

Good discussion guys... I have now taken my muffler delete pipe out and I have gained some low end power back.. haha.. I'll save the pipe for when my warranty ends and I start changing lots of things.. =)
As for the remap, I'll start with a tuningbox (racechip) first, as its easy to remove when sending the car in for servicing.. couldn't find many reviews on racechip tuning boxes though..I guess I'll be one of the first to extensively test it!

zombie1066@ thanks for the info! glad to know an aftermarket exhaust + remap sits well with the RCZ! Yea Im very weary of changes to the intake/exhaust setup of cars. My friend had a prelude with an exhaust twice the size of stock.. It didn't really move very fast...

mr shiney@ yes that is a very fast 10 second Defender.. My friend only got his Td5 down to 12 secs.. I love defenders and will get 1 one day... haha... when you added a larger intercooler, did that increase turbo lag? Or did fueling changes help reduce it? Hope we woudn't get booted off the forum for being off-topic! haha

 

[Anonymous]

remeber simply bolting on a "tuning box" is just "fooling" the car AF ratio. Short term power increase, long term stress on engine and increases the risk. DERVS are more resilient seeing as they are very heavy and strong engines as standard.