Exhaust Temps for CBR600

[Bear]

Does anyone out there have an exhaust temp. for a CBR600 engine? Right now we do not have an engine running to get this infor. 8000 to 10000 RPMs at any timing.

[BeaverGuy]

I don't know about the Honda motors. But today we were running our ZX6R and the EGTs were staying between 1000-1100 Farenheit regardless of RPM.

[Bowtie Man]

Hey,
I've been trying to tune my intake on the dyno, but have hit a wall with some high EGT's. I've changed the ignition timing in both directions as well as changed the A/F ratio in both directions, with no luck. I also changed to a colder set of plugs, and have played with dwell for the coils, still with luck. I don't know the exact temp as my thermocouples are in transit, however the header is glowing cherry red from the port to 6 inches up the flex pipe attached to the header from an RPM of 5000 and on. If you have any suggestions, as to another approach I can take I'd appreciate it.
Thanks,
Luc

[Bowtie Man]

I forgot to say i'm running an 01' F4i

[Erich Ohlde]

what ignition timing are you running, and what have your tried (e.g. 40-45degrees?). What kind of material are you using for your header, and what wall. Do you have any airflow over the header (fans, etc)? What AFR/Lambda are you running? Also is this WOT or part, full load and holding constant rpm or transient.

[Bowtie Man]

part throttle roughly 35% unloaded or loaded doesn't matter, it's at 28 degrees of advance have gone over 30, stock header at the moment, no airflow across the header, AFR's ranging from 12.5 to 17

[KU_Racing]

AFR- egt is comin from running too lean. you shoulde be at about 11:1 or slightly leaner (11:1-11.5:1). We had a high EGT problem last year, and running richer fixed it. Also, are you using sequential or batch-fire injection? Batch fire will run cooler- the injector will spray the valves with fuel on the power stroke, cooling them down.

[Chris Boyden]

Batch fire or not, it doesn't spray the exhaust valve(s).

[KU_Racing]

true- but I have seen egt's drop 50-100 degrees when switching to a batch fire system here at work (usually on race v8's, 2000 hp+)

[Erich Ohlde]

Ok, first off, you are way too retared on your ignition timing. Tune your afr for 13:1 then bump ign timing to about 40 degrees. should take care of the problem and you'll have a bunch more torque

[Bowtie Man]

personally I was under the impression that batchfire would increase the EGT as it would light off any remaining hydrocarbons not burned during the combustion event when entering the header

[Nigel G.]

First, make sure you have your EGT probe as close to your exhaust valve as possible, we noticed around a 300 degree drop from valve to collector. We checked the EGT with the stock Honda F4i ecu under full load out on the track and never saw it peak over 1300 degrees. Keep in mind that is hard acceleration with a ton of load. For the most part the EGT was between 800-1100. The temp changes quite a bit when you are driving out on a track. Now we are tuning a stand alone and using our reference EGTs to know our limit. Hope this helps.

[Superfast Matt McCoy]

If your exhaust is too restrictive it will make for lots of hotness.

http://students.ou.edu/B/Matthew.L.Brown-1/dynoorange.jpg

we went from a final exhaust diameter of 1 3/8 to 1 3/4 and it is much less orange now.

also more power.

[Bowtie Man]

That's a pretty decent distribution across the cylinders http://fsae.com/groupee_common/emoticons/icon_smile.gif we're still increasing the timing and the temps are slowly coming down. Our header material just arrived so it will be fabbed up this weekend and ready to go next weekend hopefully "crossing fingers" thanks for all your help, see you in a couple months

Luc