ACE Header Independent Testing Results and Review - 199.6WHP on CA 91 Octane

[shellslinger]

Not sure if this has been answered yet, will this throw a CEL? It seems like it will most likely since there's not cat.

If it does throw CEL, anyway to remedy?

Thanks all.

[steve99]

Originally Posted by shellslinger

Not sure if this has been answered yet, will this throw a CEL? It seems like it will most likely since there's not cat.

If it does throw CEL, anyway to remedy?

Thanks all.

Your wasting money buying this (or most other headers) without getting a tune to suit. you will likely only see about 1\3 of the possible gain without a tune.
even most aftermarket catted headers will thow a cel eventually
02 spacer on second 02 sensor may work but its an expensive header and would be wasted without proper tunning
in the tune they will disable cel code P0420 cat efficiency

[shellslinger]

Originally Posted by steve99

Your wasting money buying this (or most other headers) without getting a tune to suit. you will likely only see about 1\3 of the possible gain without a tune.
even most aftermarket catted headers will thow a cel eventually
02 spacer on second 02 sensor may work but its an expensive header and would be wasted without proper tunning
in the tune they will disable cel code P0420 cat efficiency

Got it thanks, was the answer I was looking for!

[MaximeT]

I will add that if you run a device that increase airflow without a tune, AFR will get too lean and damage the engine.

[steve99]

Originally Posted by MaximeT

I will add that if you run a device that increase airflow without a tune, AFR will get too lean and damage the engine.

the ecu will detect a difference in measured afr (by 02 sensor) and commanded afr (what the ECU is asking for) in closed loop operation and alter the LTFT compensation to bring these values closer together. while compensations may not be ideal they will then be applied in open loop operation to correct afr differences.

your more likely to run into issues changing an intake than changing header.

you not going to get much advantage from header unless you alter intake and exhaust cam timing to take advantage of the different flow characteristics of the header and lack of catylitic converter.

The stock tune runs very rich afr targeting (commanded AFR) of about 10.7 afr at higher rpm unlikely your going to get it to run lean enough to do damage on stock tune by running a header alone. Leaning it out a bit gives more power.

most tuner target about 11.5 to 12.5 on petrol NA

[MaximeT]

Originally Posted by steve99

the ecu will detect a difference in measured afr (by 02 sensor) and commanded afr (what the ECU is asking for) in closed loop operation and alter the LTFT compensation to bring these values closer together. while compensations may not be ideal they will then be applied in open loop operation to correct afr differences.

your more likely to run into issues changing an intake than changing header.

you not going to get much advantage from header unless you alter intake and exhaust cam timing to take advantage of the different flow characteristics of the header and lack of catylitic converter.

The stock tune runs very rich afr targeting (commanded AFR) of about 10.7 afr at higher rpm unlikely your going to get it to run lean enough to do damage on stock tune by running a header alone. Leaning it out a bit gives more power.

most tuner target about 11.5 to 12.5 on petrol NA

Damn, 10.7 that's a lot of fuel.

[steve99]

Originally Posted by MaximeT

Damn, 10.7 that's a lot of fuel.

yes get a stock rom and open it in romraider :-)

[MaximeT]

Originally Posted by steve99

yes get a stock rom and open it in romraider :-)

Thx for the screen shot.
Does the stock engine goes to 1,4 load at 7400 rpm ? Sounds like a lot of power to me (if not lost by rich AFR).

[Tim Radley]

Originally Posted by steve99

yes get a stock rom and open it in romraider :-)

Why on earth would they make it run that rich?

[MaximeT]

Looks like they are the last few points of the map where you're not supposed to go. They are calibrated to keep the engine safe, just in case you go there for some reasons.
That's my 2cnts

[steve99]

Originally Posted by Tim Radley

Why on earth would they make it run that rich?

I can only assume its for knock resistance on rubbish fuel like in south africa where you can only get 95 ron fuel, and just being safe



all the stock roms run same fuel table any country

[steve99]

Originally Posted by MaximeT

Thx for the screen shot.
Does the stock engine goes to 1,4 load at 7400 rpm ? Sounds like a lot of power to me (if not lost by rich AFR).

on stock car stock tune you generally wont see loads much over than 1.2

[MaximeT]

Originally Posted by steve99

on stock car stock tune you generally wont see loads much over than 1.2

Thanks.

[Tim Radley]

Originally Posted by steve99

I can only assume its for knock resistance on rubbish fuel like in south africa where you can only get 95 ron fuel, and just being safe



all the stock roms run same fuel table any country

Wow. That's pretty bad then. Surely with lambda and knock built in it can deal with fuel changes. 10.7 is the road to bore wash on an NA engine.

Dyno chart for my bone stock 86 attached. UK car with 100 miles on it.