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EGT's and A/F Ratios
Posted: Thu May 26, 2005 1:28 am
by PeteGLH
As explained in my last 3 of 4 posts (;)) I am now a proud owner of a 91 SS, and I am lovin' it!
I Got my EGT hooked up, A/F and Boost Gauge. In my old turbo cars (Mainly Turbo Dodges... I know I know, ugh... but sooo much fun) I would run pretty much full rich ( Last Green on A/F ) and run about 1400-1450 WOT and 1300-1350 cruise speed on the EGT. Anything over 1550-1600 was of GREAT danger for a Turbo Dodge as they were pretty fragile.
Now driving around my SS, I notice WOT around 1500-1550 and cruise (110-120 km/h -- 65-70 mph) to be around 1400. Also, A/F will just barely reach rich... not completely rich on WOT at 8 psi.
My old Turbo Dodge experiences urge me to back out as the EGT's climb as well as the not full rich reading on the A/F.
Are these normal numbers for these cars?! I would love to hook up my MBC and go for maybe 10-11 psi, but with these EGT numbers and A/F readings I am a bit concerned.
Hoping to get some feedback as I am not yet accustomed to this car and what it is able to withstand!
Thanks in advance!
Posted: Thu May 26, 2005 3:07 am
by IronMonkeyL255
My uncle used to have a KILLER Shelby Charger. That thing was fast as all hell.
Posted: Thu May 26, 2005 3:56 am
by THAWA
Did it Go like Hell?
Posted: Thu May 26, 2005 4:40 am
by azn2nr
narow band af gauges dont tell you alot but thats gettin pretty hot but also kinda normal from what i hear
Posted: Thu May 26, 2005 6:33 am
by IronMonkeyL255
Yup.
He was looking for a new project car. He had found a Charger GLH, but it was out west. I am trying to find him a cheap Impreza or Legacy Turbo.....
Posted: Thu May 26, 2005 9:42 am
by 93forestpearl
do EGT's lower with an I/C? TBE?
Stuff starts to melt st 1500 F.
Posted: Thu May 26, 2005 12:42 pm
by dzx
I think an intercooler would generate more heat because its cooling the air charge but then the engine is supplying more energy, you get a bigger explosion in the cylinders. Also you still have the turbo which is probably the hottest thing under the hood. You can open up the hood at night after getting on it for a while and the turbo will be glowing a bright red. Dont touch tho....
Posted: Thu May 26, 2005 2:37 pm
by free5ty1e
aw... why not? It's so pretty.....
Posted: Thu May 26, 2005 2:41 pm
by legacy92ej22t
It only doesn't hurt for a second.
:)
Posted: Thu May 26, 2005 6:06 pm
by PeteGLH
My Omni's were all pretty fast (best E.T 13,96 @ 99 mph) with very little mods, IC, 2.5" Exhaust and MBC set at 15psi on stock Turbos. I also had swapped the turbo motor and manual tranny into a late 80's Minivan which ran a best of 14,77 @ 93 on 12 psi. That was funny as hell!!
Those things were cheap, fun to drive, but not very reliable....
Anyhow, I do feel that these EGT temps are kinda high... am I wrong in thinking so?!
Motor runs and feels great, no blowby whatsoever, but I little too hot for my liking... based on my old experiences... and junkyard engines aren't so easy to find for a Turbo Legacy...
I have been told that the temps were quite normal for these cars... would just like to have that confirmed.
I miss my Turbo Dodges, but with the winters up here (Quebec City) a good solid running AWD car is ideal!
Anyhow, LMK what you guys think!
Posted: Thu May 26, 2005 7:08 pm
by vrg3
Where did you place the EGT probe on your Mopar and on your Legacy? The placement might be making a lot of the difference.
I'm not very familiar with the Dodge turbo setups, but one thing to understand about the stock Legacy turbo is that it's practically always on boost. Even when you're just cruising on the highway you frequently go on boost. And the turbos are tiny.
=)
Posted: Thu May 26, 2005 10:30 pm
by PeteGLH
I have noticed that the stock setup is almost ALWAYS in boost. I would never go into boost with the Turbo Dodge unless I really got onto it. However, the turbo was much bigger as well (Garrett T3 vs VF-11)....
I am thinking that a bigger turbo would help this "easy spool" condition to go away.. and maybe even help with fuel consumption??
Anyhow to get back to the point, the probe on my TD's (Turbo Dodges) were placed around max 3" from the #1 exhaust port, meaning about 6 " before the turbo. #1 on TD's is known to run the richest so that might affect EGT Temps a bit. On the Legacy I'd have to check where it's at... I didn't install it myself as I had no time to do it.. and I didn't check the quality of the install (which I plan to get around to tonight...) I'll get back to you, but my guess would be somewhere between 4 and 6 inches from the exhaust port... (I HOPE! or else my EGT'S are pretty high!)
Anyways, if you guys are running cooler with comparative EGT probe placements, I'll get my stuff checked out. (O2 Sensor, bigger injectors, FPR, etc...)
I would love to run more boost, but this kinda iffy situation is forcing me to hold back
Thanks again!
Posted: Thu May 26, 2005 11:25 pm
by vrg3
A bigger turbo will help. A less restrictive turbine and a more efficient compressor will improve volumetric efficiency, reduce heat, and let you do more without boost.
Your probe probably isn't 4 to 6 inches away from a port... there isn't a good spot that distance away I don't think. One popular place to put it is in the middle of the driver side exhaust manifold, which is maybe a couple of inches from the ports on that side.
Posted: Fri May 27, 2005 1:28 pm
by free5ty1e
My EGT sensor is in the #4 exhaust header pipe (since #4 is the last cylinder in line for fuel) before the turbo. On boost, even at 10-11 psi, I've seen the EGTs go above 1500. More often with partial throttle boost than with WOT boost, of course.
Gauge maxes out at 1600* F, never seen the Legacy let it go above 1550. My turbo Saturn, even at 4psi, was running right around 1600, which I was not happy with, but then again those things were never meant to take boost...
Posted: Fri May 27, 2005 8:39 pm
by THAWA
#4 is the first cylinder in line for fuel. Maybe you mean #3.
EGT
Posted: Tue May 31, 2005 1:08 am
by PeteGLH
EGT is right in the jonction between the two runners on the pass side (1-2 or 3-4?) .... therefore maybe 2-3 inches from the exhaust port.
Anyways, It runs a little lean, so I'm not stepping into it too much. Clean up all my fuel related components and see what goes on.
Anyone ever tossed the canister? I've always dumped 'em on my old Mopars and never noticed a difference... not even on hot days ... Maybe these cars don't handle it too well... anybody have any experiences with this?