Afr

[mariusz]

just to let every one know that i instolled fuel cut defender yesterday. my CX7 boost up to 18 PSI , and that's just pod air filter and high flow cat converter.

also AFR (air/fuel ratio) was measured ,with the higher boost and it's only 10.5. wich so rich, i can only imagine that without mods AFR in in 9's. two thing come out of it:
1. that's why our fuel ecconomy is so bad for a 4 cylider car
2. there is plenty!!! room for furter mods that improve boost and indirectly lift AFR.

any comments

PS did any body installed boost control and if it made any difference in the low-mid range???/

 

[CX-7owner]

I'm going to turn up the boost soon so your information is helpful..

Do you have AWD? Also, how is the tranny acting when you really get on it?

 

[astraelraen]

I have a manual boost controller that I bought a few months back that I've been thinking about playing with now that I got the dashhawk to monitor things.

If it wasn't 25 degrees outside I'd probably go try it out.

 

[hectik1]

It runs rich to protect the engine. Most stock cars will hit 10:1 or lower.

 

[mariusz]

i have AWD and transmittons has no obvious problems, one thing i did noticed that it chancges gears up a bit sooner vs speed tha before.

in regard to AFR 10:1 is very rich 11-12:1 are still safe but give max performance.

 

[SuperStretch18]

i have AWD and transmittons has no obvious problems, one thing i did noticed that it chancges gears up a bit sooner vs speed tha before.

in regard to AFR 10:1 is very rich 11-12:1 are still safe but give max performance.

MS6's are blowing engines at 12:1. The DISI needs a richer mix for safety reasons...

 

[CX-7owner]

MS6's are blowing engines at 12:1. The DISI needs a richer mix for safety reasons...

They do have different engine management, the MS3 has no problems at 18psi on the stock IC.

 

[AzMz3]

MS6's are blowing engines at 12:1. The DISI needs a richer mix for safety reasons...

This is far from true. What other DISI do you know that is running as rich as the MS3/MS6/CX-7.....none.
There are a few that are tuned from the factory alot better than the Mazda's. It is definately not for safety as were are running in the high 9afr when other DISI are in the mid 12afr stock and tuned.

I seriously doubt the Ms6's are blowing because of their AFR.

 

[hectik1]

DISI = high compression + high boost

Leaning out the AFR, along with bumping the already high boost increases chances of detonation and ultimately blowing the engine.(freak) It is a fine line.

 

[Haltech]

DISI = high compression + high boost

Leaning out the AFR, along with bumping the already high boost increases chances of detonation and ultimately blowing the engine.(freak) It is a fine line.

Incorrect information... You need to shoot over to the MS3 section for some school.

 

[SuperStretch18]

This is far from true. What other DISI do you know that is running as rich as the MS3/MS6/CX-7.....none.
There are a few that are tuned from the factory alot better than the Mazda's. It is definately not for safety as were are running in the high 9afr when other DISI are in the mid 12afr stock and tuned.

I seriously doubt the Ms6's are blowing because of their AFR.

So what is the explanation to why the stock tune is so rich? The fact that a different direct injection engine performs differently shouldn't be a surprise as it's not the only variable. What is the construction of the rods & crank? How much boost are they running? What compression rate? There are a lot of other variables besides just afr.

Same goes for blown engines, so you are probably right that AFR is not the only things causing the MS6's to blow. It was irresponsible of me to simply state that ##:1 is the line in the sand, but it is just as irresponsible to say that anyone can just turn up the AFR without looking at those other variables as well. That's all I'm saying...

 

[AzMz3]

So what is the explanation to why the stock tune is so rich? The fact that a different direct injection engine performs differently shouldn't be a surprise as it's not the only variable. What is the construction of the rods & crank? How much boost are they running? What compression rate? There are a lot of other variables besides just afr.

Same goes for blown engines, so you are probably right that AFR is not the only things causing the MS6's to blow. It was irresponsible of me to simply state that ##:1 is the line in the sand, but it is just as irresponsible to say that anyone can just turn up the AFR without looking at those other variables as well. That's all I'm saying...

Poor tuning! Maybe safety for future mods. I too would be curious as why Mazda tuned it like that.

And no you just don't tune for AFR without looking at other factors. But it is pretty common for DISI/GDI vehicle to run richer then stoich for best power.
And as stated running too rich in DISI/GDI enigine can cause damage.

 

[hectik1]

Incorrect information... You need to shoot over to the MS3 section for some school.

You telling me that the DISI turbo direct injection is not running high compression? Or that the car isn't running high boost?