[maxi-overdose]

iTrader: (3)

while I was driving on a on ramp to another freeway today, I noticed that a Boxter was following me really close...and I really wanted to find out if I can run with this nice machine.

once I got off the ramp, I pulled to inner lane and let him get right next to me. he saw me pulled off and quickt he caught up with me and stayed in the outter lane. the road was clear @ 6:05am.......got my car at 4th gear, 2500 rpm @ 60mph. I know once I floored the pedal, she will downshift to the second to 5500rpm and I might have a chance to pull on him.

once I am ready to go....I took a quick glance at my EGT and turned out that my EGT is really high. 750c @ 60mph, 2500rpm. we were running on an uphill road too. affraid of ruining my car, I didnt step on her....and I had no choice but to watch the porsche getting away from me.


Why is my EGT so high? at cruising, it seems fine....80mph and I am only getting 640c the most. but once on uphill road (only 10% incline the most) it just works all the way to the top.

am I detonating? I didnt hear anything.....the only noise that I have is the ypipe rattling against something (it doesnt show up all the time). If I am detonating....isnt my knock sensor supposed to retard my timing and make my car slower?

is my stock cat-back too restrictive??


thx for any help~

PCGuRu2K

iTrader: (34)

Wow.. 1382 @ 60mph definitely high.. When I cruise @ 80 my egt is only like 1200.. When you drive the car hard the EGT does go up..

Now we have a porshe boxster thinking he can take a boosted max. If it was just a regular and not a "s" you should have been able to take him

[maxi-overdose]

iTrader: (3)

that's about right for my EGT temp @ 80mph, crusing....640c = 1200f

I dont know what caused the EGT to go that high at that moment. (it is always high when I drive that uphill road) It was a curvey on ramp and follow by a 10% incline freeway.

Quote:

Now we have a porshe boxster thinking he can take a boosted max. If it was just a regular and not a "s" you should have been able to take him

hopefull I will meet him again~

Stephen Max

iTrader: (59)

You have to give it more gas when going uphill. More gas = higher EGTs.

[maxi-overdose]

iTrader: (3)

hmmm.....but I want to lower the EGT so that I can boost with the porsche though.

I was partial throttling again to adjust to the right rpm for bost.

CBass69187

iTrader: (4)

Have you considered getting a new exhaust? That should help a little but an intercooler would be nice also. Are you tuned?

[maxi-overdose]

iTrader: (3)

I am thinking about fixing the stock bpipe to get rid off those crushed section. I want to see how much will that cost from a local shop.

intercooler might be too expensive for me. I am thinking about using water/alcohol injection. cheaper (400)...but you have to fill the resevoir frequently.

I am not tuned, super rich under 10:1 AFR.

Stephen Max

iTrader: (59)

You probably would have been okay once you went to WOT and got that 10:1 fmu into action.

[maxi-overdose]

iTrader: (3)

I have an 8:1

wouldnt high tempearture damage the engine interals?

[maxi-overdose]

iTrader: (3)

and I just read this article....

detonation will cause the EGT to drop...

now I am confused...I thought it will raise the EGT.

Stephen Max

iTrader: (59)

Sorry, I meant 8:1. If you are running rich at WOT, like you've said in other posts, then even though your EGT was higher than you expected at partial throttle at 60 mph (but that was because you were going up the hill), once you went WOT your rich, fmu-controlled afr would have kept temperatures down. In theory.

Where did you read about detonation causing EGT to drop? I'm not disputing, I'd like to read that article.

[maxi-overdose]

iTrader: (3)

http://www.streetrodstuff.com/Articl...e_Basics_V.php

here is the link.....I got it by searching under yahoo with "detonation and EGT"

thx for your help

Jer

iTrader: (2)

You folks are confusing me, but I betcha redoing your exhaust will make your EGT's look much better

Stephen Max

iTrader: (59)

Thanks, Maxi. Pretty interesting stuff, especially this:

"We now know that the Hemi design is at the worst end of the spectrum for a combustion chamber "

now that Dodge has a big advertising campaign selling the Hemi engine.

[maxi-overdose]

iTrader: (3)

Jer: you had stock bpipe with EGT gauge, right? how does the EGT look after you get the aftermarket car-back?


no problem stephen....why is this line so interesting? sorry that I dont have any knowledge in hemi engine.

I didnt see that boxster today. but instead, an M3 (last gen) was following me and I sure gave him a good run!

Stephen Max

iTrader: (59)

It's interesting because Dodge is presently selling the Hemi engine as being something really desirable, based on a thirty year old reputation. When I was in high school (1970) the Dodge Charger and Plymouth Roadrunner had Hemi engines, and they were hot stuff. But it turns out that more modern combustion chamber designs are considerably better when it comes to high performance engines. So much better that this article says the Hemi combustion chamber is the worst.

MardiGrasMax

iTrader: (14)

Dont sweat the EGT's till you got well into the 800's, like 820 or so. My bet is when you floored it from 750 your EGT's would have dropped because the FMU would have ritchend it up. Ive seen it happen. Part throttle cruising on the interstate I see 760 all the time, then nail it and it drops.

Stephen Max

iTrader: (59)

From reading the article: the reason the EGT gets lower once detonation occurs is that detonation breaks through the thermally insulating boundary layer of gas at the piston surface and heat goes out of the exhaust gas and into the piston (which is what causes piston damage, as well as the explosive shock). This cause the engine to overheat, which increases detonation further.

[maxi-overdose]

iTrader: (3)

I forgot to mention about this...

you and Stephen are right and I tested today too. The EGT was 750 before boosting....once I floored the pedal, it went up a little and then dropped back down to 720 and stayed there. I floored it again right after and it didnt go up.





thx

JAY25

iTrader: (38)

once you floor it and the FMU detects boost your FP will go up and it wont let your EGT surpass 800 Degrees Celsius, My EGTs are between 600-720 Celsius just regular crusing.

Quicksilver

iTrader: (1)

Good info guys...more food for thought for me!

Jer

iTrader: (2)

Afraid I never took the route on this car