High EGT's...any suggestions

[Rez90]

I have a hahn S16G with a S-AFC on my 95 GST. I have upgraded injectors and all of that other stuff as well. I've been told that i want my O2 voltage between .90-.92 for the best power. when it reads in that area, the car seems fast as hell, the problem is that my EGT's are getting very close to 1600 way before i would actually like to let off the gas. This is especially bad on the highway where i'll be crusing at 70-75 mph and someone will tempt me to get in a high speed ordeal, my EGT's will be really high really fast. i guess i'm asking whether i have to run my car really rich to keep the EGT's down, which kinda sucks. I was under the impression that if i had my O2's reading .92ish, the EGT's would stay in a safe range.
any suggestions?

 

[Violater101]

Well, the odds are that you are knocking and hence the fast rising EGT's. Without a way to adjust your timing, your going to have to add more fuel to get the EGT's down if I am not mistaken. You are correct in that you want your A/F around .92 ideally on pump gas. How much boost are you running and on what octane? You might want to lower the boost some if you don't want to add fuel back.

 

[L2RTSiAWD]

Exactly. You will have to add fuel to lower egt's or turn the boost down so your current fuel trim's will be rich enough to keep EGT's at a safe level.

Later,

 

[Rez90]

i'm running about 18 pounds usually on 94 octane. i don't have a timing controller on the car and i dont' know much about knock and what it involves. do you have any info or links i could check out in regards to it to get a better understanding?

 

[L2RTSiAWD]

Really It looks like you need a Pocketlogger to tune your car at this point.

Later,

 

[Rez90]

i thought that you could only get pocketloggers for 1g cars. can you get them for 2g cars? and can you tune with them or only do datalogging. cause if you cant tune with them, i'd have to get an ITC or something of that effect to actually tune my timing and fuel together.

 

[L2RTSiAWD]

You can't tune only log. Pocketloggers are for 1G and 2G(I have one) you don't need an ITC, just use they afc to control your fuel and let the ECU control your timing.

Later,

 

[Rez90]

question. i have an afc, but you dont' say i need an itc. but i should get the pocketlogger. if i'm going to let the ecu control the timing, then why do i need the pocketlogger. would it just be to make sure i'm staying safe?

 

[L2RTSiAWD]

You get the pocketlogger so you can see the timing and make sure your getting a good timing curve. You can see the timing and know if your too lean(timing pulled) or perfect(timing being constantly added).

Later,

 

[RetardedAWD]

There is a happy medium with adding fuel to cool EGTS. If you add too much fuel they will actually be higher because fuel burns not only in the cyl but in the exhaust manifold .

 

[civic619]

Originally posted by L2RTSiAWD
You get the pocketlogger so you can see the timing and make sure your getting a good timing curve. You can see the timing and know if your too lean(timing pulled) or perfect(timing being constantly added).

Later,

When you mean timing being added, are you implying the ecu will advance the timing degrees??

and when you are refering to the numberical value of the timing log, is that in Degress??? 16Deg?

 

[autronicDSM]

Yes, ECU will advance the timing for you as long as you don't knock. Logger is pretty important to have so you can make sure everything is working like it should.

 

[doug]

http://www.racingknowledge.org/forum/topic.asp?TOPIC_ID=1348

 

[boostle]

Originally posted by RetardedAWD
There is a happy medium with adding fuel to cool EGTS. If you add too much fuel they will actually be higher because fuel burns not only in the cyl but in the exhaust manifold .

Not quite. I run my car very rich 'cause i'm mostly doing long highway runs and my egt's never go far past 800c.

 

[doug]

Yeah, it's only when your timing gets pulled so much that combustion occurs late enough in the cycle that it's not quite done "combusting" as it heads out the exhaust manifold and shoots your EGTs up. I'm pretty sure that's what's happening with me right now. I will be logging it soon, I hope, to make sure.

 

[Phoenyx]

Originally posted by L2RTSiAWD
Really It looks like you need a Pocketlogger to tune your car at this point.

Later,

A pocketlogger will do him good at this point however, he will only be able to "observe" his timing. Sure, if it's reading low, then he's more likely knocking. However, he could get away with adding (or subtracting) more fuel across the whole rpm range and see when and where his EGTs are rising also.

I disagree with not needing an ITC or some form of timing control. You can get much more HP out of the car when you are able to advance the timing beyond what the ECU will allow (provided no knock). It is definitely my secret weapon.

-M