Lean or Rich

[redfire03 cobra]

Guys,

Will adding a offroad h-pipe and catback generally make you run lean or rich over the stock set-up. It is freeing up airflow, so I am not 100% sure which way it will affect your air fuel ratio. Any comments are greatly appreciated. Peace!

 

[Tat98Cobra]

Guys,

Will adding a offroad h-pipe and catback generally make you run lean or rich over the stock set-up. It is freeing up airflow, so I am not 100% sure which way it will affect your air fuel ratio. Any comments are greatly appreciated. Peace!

Changing exhaust should not affect your A/F ratio. With more air flowing, the MAF should compensate by adjusting fuel - therefore maintaining the desired A/F.
Messing with MAF's are usually what alter that ratio (usually leaning her out) - which makes people THINK that aftermarket MAF's yield more HP.

peace

 

[redfire03 cobra]

Hey Tat98 Cobra,

I was thinking of getting the K&N FIPK you have, did you get your car dynoed after the filter was installed. What performance gains did you get? Thanks! BY the way, do you have a slight ticking noise coming from your left hand side wheel well. I took my 03 cobra to our local dealership for this, and they said it is normal. Since you have an 03, could you let me know. The best way is to pull close to a wall on your drivers side and roll down your window, can you hear anything? Peace

 

[redfire03 cobra]

Hey Tat98 Cobra,

I was thinking of getting the K&N FIPK you have, did you get your car dynoed after the filter was installed. What performance gains did you get? Thanks! BY the way, do you have a slight ticking noise coming from your left hand side wheel well. I took my 03 cobra to our local dealership for this, and they said it is normal. Since you have an 03, could you let me know. The best way is to pull close to a wall on your drivers side and roll down your window, can you hear anything? Peace

 

[The Factor]

The ticking your hearing is a recall they had on the drivers side head,but there not replacing them anymore because it dosnt hurt performance or cause any problems.I had mine replaced when they were still doing it,you can tell whitch ones were done because the head will be blue along the edge were it meets the block.As far as your air fuel mixture changing,well mine did when I put a bassani x-pipe with no cats on my 03 cobra,I took it for a dyno and it was really lean,Fortunately I took it in the next day after installing and drove it easy until i checked it.2 weeks earlier I took it for a dyno and dialed it in.So the x-pipe definately leaned mine out ,I had too add around 3 to 4 % on the top end and a little on the bottom.The x-pipe gave me about 20 more RWH

 

[redfire03 cobra]

03yellow venom,

If you need to add fuel to the mixture because of my offroad h install, do you need to bye the tuner. I currently have the factory tune, so can they just add fuel to that factory tune, or does the car need to be tuned with a tuner. I ask this because what turned out to be a simple cost for a bolt on, will cost alot more to have the car tuned, like $500. Peace!

 

[Tat98Cobra]

Hey Tat98 Cobra,

I was thinking of getting the K&N FIPK you have, did you get your car dynoed after the filter was installed. What performance gains did you get? Thanks! BY the way, do you have a slight ticking noise coming from your left hand side wheel well. I took my 03 cobra to our local dealership for this, and they said it is normal. Since you have an 03, could you let me know. The best way is to pull close to a wall on your drivers side and roll down your window, can you hear anything? Peace

No ticking on mine - my build date was april of 03 so I believe I am after that ticking head issue.
03yellow - something is wrong if exhaust leaned out your a/f. Was the weather different on your original dial-in? On stock factory program, Maf should keep A/F's constant - unless of course you're pegging your MAF

peace

 

[Uncle Meat]

Will adding a offroad h-pipe and catback generally make you run lean or rich over the stock set-up.

Simple answer is it will lean you out a little at full throttle, but the amount will be negligible. On a stock 03 Cobra with it's super rich factory A/F ratio you shouldn't have to worry about it though. It won't lean it out enough to do damage. You do need to tune it though if you want to get ALL of the possible performance gains out of those exhaust mods. Just bolting them on will gain you some HP & TQ, but if you get the car tuned specifically to work with those new mods you'll make even more power!

With more air flowing, the MAF should compensate by adjusting fuel - therefore maintaining the desired A/F. Messing with MAF's are usually what alter that ratio (usually leaning her out) - which makes people THINK that aftermarket MAF's yield more HP. peace

This is true until you mash the loud pedal all the way to the floor (WOT). The ECM will do it's best to maintain a stoic 14.7 A/F ratio when cruising at part throttle. The tables the ECM reads from for WOT are different and this is where the custom tuning comes in and makes all the difference in the world. Tat98Cobra is right on the money about those aftermarket MAF's. Just bolting one on without getting the car specifically tuned for it can be dangerous.

I was thinking of getting the K&N FIPK you have.... What performance gains did you get?

Dyno proven gains of 25RWHP on a STOCK '03 Cobra. Easy and quick to install too!

The ticking your hearing is a recall they had on the drivers side head,but there not replacing them anymore because it dosnt hurt performance or cause any problems.I had mine replaced when they were still doing it,you can tell whitch ones were done because the head will be blue along the edge were it meets the block.

Correct on the ticking issue. They are refusing to replace the drivers side heads on ticking '03's now. I guess I'm lucky 'cause I got mine replaced twice under Article No. 03-11-4 dated May 23, 2003. As for the blue stripe deal... it don't mean squat as far as redesign! That was a nasty rumor which got started about the heads having a blue stripe that supposedly annotated the newer design. Not true. The heads on our cars in bare form are identicle. They can be built up as a passenger side head or a drivers side head. The blue stripe only indicated that it was assembled as a drivers side head and not a passenger side head. That stripe of blue paint was put there for the Niche-line workers.

If you need to add fuel to the mixture because of my offroad h install, do you need to bye the tuner. I currently have the factory tune, so can they just add fuel to that factory tune, or does the car need to be tuned with a tuner. I ask this because what turned out to be a simple cost for a bolt on, will cost alot more to have the car tuned, like $500. Peace!

There are a couple ways to get a new tune. The hand held Predator or Superchips tuners are one method. You could also go to a tuner who has the SCT system and they can directly flash your ECM with an updated tune, this way you don't have to buy the hand held unit. Either way you will need a dyno pull or three with wideband support to ensure the tune is correct. No way around it redfire03, if you want to be absolutely safe....you're going to have to pay one way or another and have the car tuned.... Keep in mind there are Cobra owners out there running exhaust & intake mods with AND without the stock pulley who are still on the stock tune! They just aren't reaping the full benefit of their mods and may possibly be running dangerously lean....


U.M.

 

[redfire03 cobra]

Thanks Meat. You covered all areas for me. I am going to put the offroad h on and have it tuned at the same time that way I will be able to sleep at night.