[Guest]

I have recently remodified the back bumper of my evoVI TME so the exhaust comes out the right hand side. This can prevent the sharp bends around the rear diff if the exhaust were to come out the left side (as standard). To reduce even more back pressure restriction i decatted my exahust and now takes longer for the turbo to spool up (Turbo lag)!!?!
If any one knows whats wrong i would really like to know.

Thanks

 

[Guest]

You need to remap your ECU if you start palying with backpressure. Also, the 90 degree bend as a major loss of power is overrated, basically it makes next to no difference. If this would be so restrictive, then think about the aftermarket manifolds, they have over 180 degree bends...

 

[Guest]

Empra,

The end effect of creating a more free flowing exhaust is normally a reduction in torque, which is what you are feeling. However, you should be generating more bhp at higher revs now. Depends on whether you are a torque or horsepower person as to what is best.

Dave

 

[Guest]

Push up the boost!

 

[Guest]

Thanks for ur replies.......um...180 degree bend in the manifold......makes sense. But dont rally cars normally adapt a straight pipe for faster reaching full boost. I like both torque AND bhp (and it does feel i am getting more power at higher end) but it doesnt feel like a reduction in torque.....more like just taking the turbo a longer time to spool to the max.

If i do change a ecu would it give me the same/better top end, or same/better bottom end and/or would the turbo spool up faster like it was before i took the cat out? my car is already running 1.1-1.2 bar boost standard - how much more can i boost it and would it solve the 'lag' problem??

And another strange thing i noticed was the high exhaust temp: if anyone has exhaust temp for the car what are the normal operating temps when pushing the car and driving normally??

Thanks

 

[Guest]

If the exhaust temp is higher (how do u know?) , it wud indicate a lean mixture which cud cause poor response at low revs.
Wot exhaust system is it and wot r yr other mods?

 

[Guest]

Yes how high is the EGT? They are typically around 900 degrees Celsius I think.

To monitor your car's engine, I came across an interesting product, a CAMP colour tactile screen with all the engine info in it (EGT, oil temp, oil pressure, boost, revs, speed, etc, etc. GBP 950 approx) This thing work under Windows CE and can update an HKS FConV ECU. Plus you can set warning levels for all the parameters etc. I will get this thing not to take chances when upping the boost...

What ECU do you have? (Can you say do you have? or should you say have you got? )

 

[Guest]

i am runnin on standard ecu for the evo TME. I dun think the exhaust temp is supposed to be 900, its too high. (I read somewhere that when u have an antilag system activated it produces extremmly high exhaust temps ranging from 900 - 1100)

Claudius: is 900C the temp u get when runing hard or cruising on normal day traffic? im thinking of changing to a programmable ecu (like autronics, haltech or motech) but think its still a bit of a waste for the standard turbo

Evoboy: i know my EGT from my gauge which is connected near the manifold. My mods are only the downpipe, exhaust, decat air filter and twin plate clutch. My exhaust system is custom made 3 (as it is straight and comes out the RHS). Does black smoke from exhaust during hard driving indicate running lean?

 

[Guest]

Empra

I havent got the thing yet so I dont know EGT, but I will let you know. At the manifold, EGT is very high, typically around 900 degrees Celsius, forgot where I read that. Could be lower if you push the car less, but still very hot.

I think you could get a programmable ECU right now, and have it set up for the standard turbo. This way, when you upgrade the turbo (and engine internals!!!) you can use the same ECU ie you dont have to buy that too. Plus you get more from your turbo right away. Dont you think?

 

[Guest]

Black smoke means you are running rich,I doubt if you have a problem with high exhaust teperatures with your current mods,oh and running rich is what you would expect thats what Evos do.

 

[Guest]

what's the preferred decat pipe size for E4 with aftermarket catback exhaust fitted ie. APEXi N1?! 2.5 or 3 straight pipe?!

 

[Guest]

Empra,
Black smoke under hard acceleration is mixture enrichment and is normal.

How much has yr exhaust temp increased by ?
Full power ex temps wud b around 800 deg c.

 

[Guest]

My exhaust temp under hard acceleration goes up to 800 - 900C.
Evo Boy: Is this 800C the temp for driving hard....beacuase i get up to 800C with jus 1 burst in second gear (ie:reving hard in 2nd gear jus once) but it quickly drops back to about 600-650C
My main concern is that the lag on my car has got noticeble worst after decat.

If anyone has a fuel regulator, i would like to know what u should set it at with jus decat exahust/downpipe and air filter (straight induction) on a TME ? wat setting if i were to boost up to say 1.3-1.4?
If anyone has anti lag i would also like to know wat the operating EGTs r while driving hard

Thanks

 

[Guest]

skevo4: my evo TME is using a 3 cat with 3 straightpipe all the way (downpipe and amp; exahust).....but as u c i have lag problems so im not sure which to recommend....maybe a smaller cat (say 2.5 ) may provide a bit more back pressure for more efficient turbo spool up and thus less lag but im not sure.

 

[Guest]

Regarding exhaust temps,

the richer the fuelling, the cooler the exhaust temp

Also,

the higher the octane of fuel, the cooler the exhaust temps

and vice versa with leaner fuelling or lower octane fuel.

Out of interest, my car never runs more than 750 degrees on my EGT gauge using Optimax fuel and a rich fuel setup, even at 1.35 bar boost at max revs in 5th gear.

Cheers

Simon

 

[Guest]

Empra,
Check yr lambda sensor in the turbo down pipe , that gas temp is 2 high 4 an exhaust only modded car.
Also check the manifold connection 2 the fuel pressure regulator.

 

[Guest]

Simon Evo: That is about the temps i had b4 some granny whacked the back of my car......but then when i was fixing the back panel i decatted my exhaust at the same time and made it straight. Wat is the octane levels u use in optimax fuel?? i use 98.
What should fuel pressure be set at for TME boosting 1.2-1.4 to minimise leaning?

I will definately chack my sensors at the manifold...maybe it got knocked out of place

 

[Guest]

empra,
Don't be concerned with actual fuel pressure , just ensure that the manifold tube connection 2 the regulator is securely connected , if it is detached lean running will result on boost.

 

[Guest]

I want to know is it mean when change the exhaust come from the right will make more turbo lag????Evo 7 exhaust come out from right as well,..Empra_EvoVI,what brand is your right exhaust??I want to put one for my Evo,it look special!

 

[Guest]

Empra,

I have an EVO IV and I too have done a similar thing with my exhaust. Mods so far are: HKS air filter, Blitz BOV, and full exhaust from turbo back - right hand side (Apexi N1 muffler, custom exhaust 3 - 3.5 , and decat). Decat was through a simple 3 pipe. I have not had any problems whatsoever with my car. It runs fine. I don't even experience fuel cuts of which I thought I would. The decat has definitely made the car MUCH louder and performance has increased slightly.