EGT\'s????

[Fish]

OK for those who might know, what temps would you map to on a rotary?

I used to map to circa 850c POST turbo on my cortina but I have a change to fit two EGT sensors pre turbo, one per port. I know that the rear rotor is most likely to see hotter temps, but not by that much.

Should I be looking at circa 900-950c?

Thanks
Fish

[Fish]

Guess those that know, are not willing to share information.

Now posted on a couple of other forums.

Fish

[iaint]

Danny,

Temps approaching 900C on a piston engine are generally seen as a bad thing, even with a few trick bits (forged pistons etc).  The temp in the down-pipe isn\'t going to be significantly lower than post turbo.  

Pre turbo is obviously going to be hotter than post but maybe (probably?) not more than 25C due to the speed of the gasses.  There may also be a drop in temp on the exit side as the pressure may be lower after the turbine.

I would guess that noone has got round to measuring that bit on a FD in the UK yet?  Either that or you\'re right and they\'re not willing to share that \'commercially viable\' info!

Maybe once you\'ve mapped the beastie you can let us know what the temp differential accross the turbos is?

Iain

[Fish]

Iain, I have had one reply offline, which I am a little upset about.

I thought the whole idea was to share niformation.

Post turbo temps can be as much as 50c less in past tests on the cortina\'s.

But yes once mapped I WILL be posting temps that I am running.

Fish

[bill shurvinton]

I think you\'ll find that very few people in the UK know what  TIT should be on a rotary, partly because few people tune using EGT these days and partly because most EGT probes will last about 2 minutes in the exhaust of a rotary.

As TIT is a function of ignition timing as well as AFR it adds some complexity to rolling road tuning, as on many rollers you cannot hold power for that long due to heat soak. On an engine dyno its a completely different ball game...Hands up those who have put  a 13B on an engine dyno in the UK?

However the other rotary forums have some good stuff on EGTs

[Carl]

Originally posted by Fish
Iain, I have had one reply offline, which I am a little upset about.

I thought the whole idea was to share niformation.

Post turbo temps can be as much as 50c less in past tests on the cortina\'s.

But yes once mapped I WILL be posting temps that I am running.

Fish

I did gladly share the info with you as one of my customers.
I just don\'t think it should be bandied about for all and sundry to see or know, especially other tuners/other tuners customers.
Sorry if that is not good enough.But I think as a valued customer I was prepared to let you know.Why should everyone know everything all the time about how to do everything that has taken some of us years to learn?
Also the old adage "A little knowledge is a dangerous thing!" comes to mind all of the time.Many informative post\'s do not put up the complete information or to the other end of the spectrum they over complicate the issue and then confuse things.Information overload becomes the thought.for some this could easily lead to creating problems for themselves.
I see many people reading info on here and other boards and only ever understanding half of it,then they get completely the wrong end of the stick.
That can\'t allways be helpful.
Also if someone reads this and then goes to their tuner or builder and they insist that the criteria given for exhaust gas temperature be stuck to cos Carl say\'s so, then their engine subsequently blows up where does that leave both my reputation and the other tuners?
Also as Bill has said,the EGT probes do not last long with the rotaries fiery breath.
I don\'t really know why you should be upset over this and very suprised.
Kind regards
Carl

[Brett]

I agree with Carl here, its all well and good sharing the information with people who are going to use it for themselves, but some people would want to make a profit on what they gleaned.

 Look at the thread marked \'FAO:Brett\' in the 2nd gen section, I bent over backwards to give him lots of usefull information and I dont have a problem with that as none of it was \'black art\' stuff, but when it comes down to info that could potentially loose a popular company(ies) money then I feel it should be restricted.

 BTW if InitalD is reading this, (Not mega poster initial-D, the other one) did you actually read that thread?  A response of some kind would have been appreciated!

[iaint]

Originally posted by IainT
I would guess that noone has got round to measuring that bit on a FD in the UK yet? Either that or you\'re right and they\'re not willing to share that \'commercially viable\' info!

Originally posted by Carl
I did gladly share the info with you as one of my customers.
I just don\'t think it should be bandied about for all and sundry to see or know, especially other tuners/other tuners customers.

Looking at my intial comment I realised it could be taken as a criticism of a Tuner not sharing the info - the single-quotes make it look a little sarcastic - not my intention!

Was going to write more about this but suffice to say commercial info is exactly that and some people on here make their living from what they\'ve invested tinme and money in for many years.

On tyhe plus side - Danny has the info he needs courtesy of Carl and I\'m looking forwards to seeing the results of the tuning.  Finding temp sensors that can live in that environment could be fun!

Iain

[Fish]

The sensors I am using are rated to 1100c, so should be able to handle what a rotary puts out. This is going by what figures I have been told. You knows its all secret squirrel around here.

Bill, as for engine dyno\'s, when Carl was building my engine I asked who else would be interested and no-one came forth. Thus making it stupidly expensive to do it.

This in conjunction with the Techedge WB02, should see good results.

Fish

[iaint]

Originally posted by Fish
Bill, as for engine dyno\'s, when Carl was building my engine I asked who else would be interested and no-one came forth. Thus making it stupidly expensive to do it.

Fish

I think that realistically there are only three ways this is likely to happen:

1) Private individual with pots of cash decodes to have the full works on an engine and gets it mapped on engine dyno.  

2) Tuner decides to do it to develop a number of cutting edge base maps in controlled circumstances.

3) Race team does it to enter a car in a series that would demand this level of development.


1 won\'t happen as a we\'re all skint from running FDs and lottery odds are steep!  Benefits might not be that great over rr or \'road\' mapping for a single case.

2 is unlikely to happen unless a large company comes into the rotary scene as I can\'t imagine that any of the tuners have that much cash floating round to invest.  Return on the cost may not be worthwhile.

3 is unlikely to happen as, as far as I\'m aware, there aren\'t any race series in the UK that are likely to be rotary friendly requiring that level of evelopment.  Plus a race engine wouldn\'t compare well with a street ening would it?

Maybe scenario 2 is more likely though but it\'d still need fine tuning in situ...

[bill shurvinton]

Pending where your techedge is, I would put your EGT probe next to that, as the controller cannot handle temperatures above 800C, which can be seen in the downpipe.

There are heatsinks available to get around this problem, but first you need to know if you have a problem. The techedge only has 2 limitations for the tuner. 1 of those is that there is no overheat alarm, so you just get wrong answers if you do overcook it

[Fish]

Bill, the headers are already drilled and tapped, so that’s where the sensors will be. The Techedge is just in the mid pipe, but this could be moved to where the stock sensor will be (i.e. just after the turbo).

Iain, from what I gather there are some SERIOUS people out there with pots of money, looking or doing serious rotary engines.

But that comes back to secret squirrel ground. The cost wouldn’t be that bad if a couple of people got together and sorted out the initial costs of mounting the engine on the dyno. (Engine mounts, oil/fuel lines and such)

Fish

[Carl]

Originally posted by Fish
Bill, the headers are already drilled and tapped, so that’s where the sensors will be. The Techedge is just in the mid pipe, but this could be moved to where the stock sensor will be (i.e. just after the turbo).

Iain, from what I gather there are some SERIOUS people out there with pots of money, looking or doing serious rotary engines.

But that comes back to secret squirrel ground. The cost wouldn’t be that bad if a couple of people got together and sorted out the initial costs of mounting the engine on the dyno. (Engine mounts, oil/fuel lines and such)

Fish

Hey Danny,
Where are all of these people with pots of money who are doing serious rotaries?
I have yet to meet any of them.
Most of them have not got much money, otherwise I think they would be driving Porsche 911\'s instead!
That is the way it seems to me anyway,LOL:rollin :rolleyes: :p :p
Kind regards
Carl

[bill shurvinton]

I have to say that monied RX owners do seem a little thin on the ground, outside some of the clientele that Pip has built up over the years (Stacey Vickers car being a prime example).

Don\'t get me wrong, I\'m all for monitoring EGT (the innovate aux box comes with dual EGT probes so you can log lambda and EGT). However using EGT is a 2 edged sword. You must know what you are doing with them or you could cause damage. For example the textbook peak NA exhaust temperature (based on complete combustion of petrol) is around 900C. This occurs at 14.7:1. However a number of variables will change the peak, such as coolant temperature, spark timing, inlet air temperature. So a best EGT on 1 engine at 1 boost will not easily transfer.

As for the engine dyno, they don\'t cost that much, so why doesn\'t the club buy one?

Bill

[Fish]

Originally posted by bill shurvinton
As for the engine dyno, they don\'t cost that much, so why doesn\'t the club buy one?

Bill

Bill, if more forum members became full members the club might just have a budget for stuff like this.

Fish