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matt · Post by **matt** » Wed Mar 01, 2006 11:24 pm

So its possible to have correct A/F ratio AND too high an EGT at the same time?

thats why you check egt after 'dyno' then reduce egt with small change to igniton timing?

Mats · Post by **Mats** » Wed Mar 01, 2006 11:59 pm

Whan tuning turbo engines you usually aim for a temperature, say high 800 to low 900 right before the turbine inlet and with proper AFR (not lambda 1!), some say never go over 850 and others gladly see 950 in peak temp all day. Usually it varies some depending on where you measure, a bit lower right after the valve then in the turbine inlet and depending on where you measure you naturally get different results.

On N/A cars the EGT won't be as critical as you don't have a 1000USD part in the exhaust to fry and you really won't see critical temperatures unless you do something seriously wrong and you will notice the power loss long before that.
On the dyno you can clearly see the result from ignition changes in the power output, on the road you're really just guessing.

The road is for base mapping to save time in the dyno but it's on the dyno you will get the power.

matt · Post by **matt** » Wed Mar 01, 2006 11:59 pm

YES I UNDERSTAND (Finally)

You can have correct A/F ratio and too high an EGT !

So to reduce egt you can advance timing,
however this may cause knock so you run A/R a bit richer and knock goes away but power down,
so u run more boost to get power back up to a point but maybe this is too much boost so you reduce boost but maintain same A/F ratio and the increase timing again this time theres no knock + good power!

I just didn't realize you could have TOO HIGH EGT with correct A/F ratio

Maurizio · Post by **Maurizio** » Thu Mar 02, 2006 12:55 am

On the dyno you can clearly see the result from ignition changes in the power output, on the road you're really just guessing.

The road is for base mapping to save time in the dyno but it's on the dyno you will get the power.

I read a lot of road mapping in the diy corner.
How good would the result be without dyno, 90% of the potential?

la_strega_nera · Post by **la_strega_nera** » Thu Mar 02, 2006 1:17 am

matt wrote:I just didn't realize you could have TOO HIGH EGT with correct A/F ratio

It is, as Mats says, primarily a problem with turbo cars, generally comes from being too small on the turbine housing and restricting the exhaust flow

matt · Post by **matt** » Thu Mar 02, 2006 4:56 am

What do you think of this ? Its in Oz too

http://www.wbo2.com/2A0/default.htm

also

http://www.techedge.com.au/vehicle/wbo2/default.htm

Like megasquirt for Wideband O2 senors + lots more functions, might make things alot easier for tuning (if you can solder it all together)

Mats · Post by **Mats** » Thu Mar 02, 2006 6:03 am

la_strega_nera wrote:
matt wrote:I just didn't realize you could have TOO HIGH EGT with correct A/F ratio

It is, as Mats says, primarily a problem with turbo cars, generally comes from being too small on the turbine housing and restricting the exhaust flow

Either that or a combination, usually you open the exhaust valve earlier on a turbo car to get some nice high pressure exhaust gasses to the turbine, sometimes (always?) they still burn when you open the valve and this naturally yield high EGT.

Post by **Zamani** » Thu Mar 02, 2006 8:08 am

Maurizio wrote:
On the dyno you can clearly see the result from ignition changes in the power output, on the road you're really just guessing.

The road is for base mapping to save time in the dyno but it's on the dyno you will get the power.
I read a lot of road mapping in the diy corner.
How good would the result be without dyno, 90% of the potential?

It depends. If you have a dynojet, it's pretty much useless for anything other than WOT tuning. In this case, road tuning, assuming there is almost no traffic and variations of grades (steepness?), is better for non WOT load sites. It's almost impossible to tune part throttle on a dynojet.

If you have a mustang or dynapack or any other load dyno, for safety reasons as well as convenience, it's much better to go with the load dyno.

My suggestion is, to cut on dyno time usage you need to do some homework. Go out and do logged data runs (load, TPS, A/F, ignition advance). Go WOT a few times and re work your fuel maps until your A/F is all ok. Then go to the dyno.

I think on the road you may not get 90% of what you can achieve on the dyno, maybe 70%?

. Simply because you don't know, as far as power goes, where you are at. But you should be close if you work the maps based on your log files. Then the trip to the dyno is just for some fine tuning work.

Barry · Post by **Barry** » Thu Mar 02, 2006 10:57 am

Mats,Mat,I usually do the road thing on a n/a engine,using the wide band sensor..Ignition timing wise,I have a very good idea of what is needed...Ive done a shit load of these like this..
Results,normally 90-95% done.I like making it richer to play safe at w.o.t.
This is then adjusted on the dyno ..

A turbo setup will also be done on the road,but with a major exception..Low boost,and NOthing more than half throttle..I creep up on the power and boost on a turbo..As long as I have the wide band in the car,Im happy..

All the drivability is done on the road..As for egt,i dont bother on a n/a engine.Turbo will get egt measured at the same time mixtures are done on the dyno..

Post by **Zamani** » Thu Mar 02, 2006 1:31 pm

Baz,

What's the best ign. adv. for my setup? All I know is I got 10 wbhp on the dyno going from 23.5 to 24.5.

ar4me · Post by **ar4me** » Thu Mar 02, 2006 1:54 pm

24.5 at 6000 RPM?

Can anyone shed some light on optimal ignition advance as function of load? Say, at a given RPM, what would be the optimal ignition advance as function of load? I understand that you can run more ignition advance under lighter load (compared to more load) without pinging, everything else being equal, but, does it buy you anything? What makes more sense? Like, what would an optimal ignition advance be at say 4000 RPM as function of load, typically?

Enough questions in there?

Jes

la_strega_nera · Post by **la_strega_nera** » Thu Mar 02, 2006 2:23 pm

matt wrote:What do you think of this ? Its in Oz too

http://www.wbo2.com/2A0/default.htm

also

http://www.techedge.com.au/vehicle/wbo2/default.htm

Like megasquirt for Wideband O2 senors + lots more functions, might make things alot easier for tuning (if you can solder it all together)

I know of a couple of guys playing with the techedge WB02 units. They love them to bits.

matt · Post by **matt** » Thu Mar 02, 2006 3:32 pm

Excellent!

pitty WBO2 not DIY kit to keep cost down its the one with all the features

2A01 DIY + Bosch 7057 sensor prob' cheapest route.......

enzo · Post by **enzo** » Thu Mar 02, 2006 3:46 pm

i bought the 2A0 DIY Kit....assembling was more difficult than MegaSquirt...but assemblet in 10h....works great!

the cheapest WB is still the Innovate LC-1 199$ including sensor (w/o display)

Barry · Post by **Barry** » Thu Mar 02, 2006 8:38 pm

Jess,You nearly dissapeared in all the replies..

My own experience,I run a lot of light load advance..typically 50 deg.As for w.o.t. Its best set up on the dyno..
What I do find with the light throttle setting is that the motor feels like it has an elastic band ready to be unleashed at light load.
I enjoy this and sometimes I actually tap off as the engine feels to be pulling very well at light load.(which it is..)
Im sure this would probably dissapear once the proper advance is dailed in..(in 20 years of programming I feel I have not go the ultimate settings yet,but have been damn close...)
I have shortened the practical life of an engine over time by having a too aggressive setup,sance detonation...

But ,yea,Light load advance works very well..check out the Haltech forum for more..