626 manifold quetsion....yet another thread

[Captain KRM P5]

has anyone checked to see if there is an aftermarket intake mani for the 626? or has mazda been left out of the entire aftermarket scene except for the rx models

obx had one listed but never produced it

 

[Crazee D]

I am N/a...lurks away...

 

[Alejo_NIN]

i purchased the 93-97 intake manifold

 

[nazgul350r]

Sweet! I will be waiting to run to the junkyard!

 

[RussianMR2]

-low_psi

"the EGR puts exhaust gas back into the intake manifold. it makes detonation and pre-ignition more of a problem."



The EGR recirculates unburned gas back into the intake to not only get better gas mileage and have better emissions, but also to cool the temperature in the combustion chamber and to prevent detonation and knock

__________________

 

[Alejo_NIN]

what you say may be true, but how is HOT AIR FROM COMBUSTION going to cool down already cooled air from the intercooler?

doesn't make sense to me...

gotta explain that better

besides...EGR only works when the car is cold, after that, it shuts off and stops working until the car cools down again....
so baiscally, EGR only works for the first 5 mins when a car is started and mostly 1 to 5 times a day....
so, how does that help:
Gas consuption
and Detonation and Knock?

i'm sorry if i came a little mad...i'm just curious...please don't flame..

-low_psi

"the EGR puts exhaust gas back into the intake manifold. it makes detonation and pre-ignition more of a problem."



The EGR recirculates unburned gas back into the intake to not only get better gas mileage and have better emissions, but also to cool the temperature in the combustion chamber and to prevent detonation and knock

__________________

 

[Alejo_NIN]

WIKIPEDIA explains it better

read the last part!::

Exhaust gas recirculation (EGR) is a NOx (nitrogen oxide and nitrogen dioxide) reduction technique used in most gasoline and diesel engines.

EGR works by recirculating a portion of an engine's exhaust gas back to the engine cylinders. Intermixing the incoming air with recirculated exhaust gas dilutes the mix with inert gas, lowering the adiabatic flame temperature and (in diesel engines) reducing the amount of excess oxygen. The exhaust gas also increases the specific heat capacity of the mix lowering the peak combustion temperature. Because NOx formation progresses much faster at high temperatures, EGR serves to limit the generation of NOx. NOx is primarily formed when a mix of nitrogen and oxygen is subjected to high temperatures.

Contents [hide]
1 EGR in Spark-Ignited (SI) Engines
2 EGR in Diesel Engines
3 Implementation of EGR
4 External links
5 References



[edit] EGR in Spark-Ignited (SI) Engines
In a typical automotive SI engine, 5 to 15 percent of the exhaust gas is routed back to the intake as EGR (thus comprising 5 to 15 percent of the mixture entering the cylinders). The maximum quantity is limited by the requirement of the mixture to sustain a contiguous flame front during the combustion event; excessive EGR in an SI engine can cause misfires and partial burns. Although EGR does measurably slow combustion, this can largely be compensated for by advancing spark timing. Contrary to popular belief, a properly operating EGR actually increases the efficiency of gasoline engines via several mechanisms:

Reduced throttling losses. The addition of inert exhaust gas into the intake system means that for a given power output, the throttle plate must be opened further, resulting in increased inlet manifold pressure and reduced throttling losses.
Reduced heat rejection. Lowered peak combustion temperatures not only reduces NOx formation, it also reduces the loss of thermal energy to combustion chamber surfaces, leaving more available for conversion to mechanical work during the expansion stroke.
Reduced chemical dissociation. The lower peak temperatures result in more of the released energy remaining as sensible energy near TDC, rather than being bound up (early in the expansion stroke) in the dissociation of combustion products. This effect is relatively minor compared to the first two.
EGR is typically not employed at high loads because it would reduce peak power output, and it is not employed at idle (low-speed, zero load) because it would cause unstable combustion, resulting in rough idle.

 

[03MSP]

what you say may be true, but how is HOT AIR FROM COMBUSTION going to cool down already cooled air from the intercooler?

doesn't make sense to me...

gotta explain that better

besides...EGR only works when the car is cold, after that, it shuts off and stops working until the car cools down again....
so baiscally, EGR only works for the first 5 mins when a car is started and mostly 1 to 5 times a day....
so, how does that help:
Gas consuption
and Detonation and Knock?

i'm sorry if i came a little mad...i'm just curious...please don't flame..

It lowers temps because it is inert gas. It does not ignite therefore temps are lowered. But if it doesn't operate during WOT I guess that is a moot point.

edit: After reading your wiki quote it seems that EGR function is used after warmup so the point is unmooted!

 

[Alejo_NIN]

ok, we weren't so far from the truth

EGR is not used at WOT thus...i was right
EGR is used in between high loads and idle...i was wrong
EGR does lower the temps...i was wrong again...you were right
EGR Hurts performance on heavy loads...i was right
EGR helps gas consumption...i was wrong, you were right

 

[Alejo_NIN]

Check the pictures...
anyone can post pics of the stock manifold?

 

[Alejo_NIN]

bump for input

 

[Alejo_NIN]

bump, check first post for updates

 

[nazgul350r]

So we need to have the fuel rail when we buy the manifolds? And that is all that is needed to make it work.

 

[Alejo_NIN]

so far, it seems like the stock mazdaspeed fuel rail should be compatible...
i am yet to verify this, since i haven't been able to install the manifold yet...

also, there seems to be a little block in the way of the injectors...it should also be verified when installing since i don't have injectors to check it out...

all in all, i think the 626 manifold is a GO!

 

[nazgul350r]

Report back in once its finished. Great work on seeing what would need to be done to wideing the market of manifolds.

 

[shabaka]

the only thing i see is...

if you use that old style fuel rail...
it won't connect to the new style quick release fuel lines

or if a person (other than Alejo) wants EGR it won't fit either
due to placement...but there's ways around that

 

[Alejo_NIN]

if you use a stainless braided line to reroute the EGR gases into the mani, i don't see why wouldn't that work!

 

[shabaka]

yeah...like i said the EGR can be worked around a bit, I even used appliance gas line I had in my plumbing van, that worked

i really was more curious about the fuel rail situation thats all
no worries

 

[Alejo_NIN]

to tell you the turth, i will only know when i instal mine..

 

[kc3635]

yo

Subbing, I wana know what kind of gains u'll get. I'll be first in line to get one installed if they're good. Good luck with the install.