Tuning EGTs, very high on low load, butterz in boost.
Thread Starter
Elite Member
iTrader: (15)
Joined: Sep 2007
Posts: 2,034
Total Cats: 5
From: Incline Village, NV
After wiring up the symtech labs circuit and egt sensor im getting way to high of cruising egts. In boost is another story of good egts.
Things i know:
Advancing timing= lower egts
too lean= high egts
Questions, why in the heck are my egts under 1500* in boost with such low timing, and out of boost driving around town its higher?
MSQ attached, sav will up the datalogg we took.
Things i know:
Advancing timing= lower egts
too lean= high egts
Questions, why in the heck are my egts under 1500* in boost with such low timing, and out of boost driving around town its higher?
MSQ attached, sav will up the datalogg we took.
Datalog showing a couple of boosted pulls and a bunch of cruising attached.
Spark map:

Looks really shitty in boost but it just detonates if I add any more advance than that.
Setup is a '95 Protege block, JE pistons, GTX rods, GT2560R on BEGi hotside parts with an MSPNP, 550cc Rx7 injectors, and a Walbro 190.
Spark map:

Looks really shitty in boost but it just detonates if I add any more advance than that.
Setup is a '95 Protege block, JE pistons, GTX rods, GT2560R on BEGi hotside parts with an MSPNP, 550cc Rx7 injectors, and a Walbro 190.
I think you need to do a couple things. FIRST, build set of det cans and tune that spark map. I think your knocksense is lying to you. If the engine truly detonates in boost at any higher number than those, then there's something wrong with the engine. You should be able to advance at least 2-3 degrees from peak torque to peak power no prolemo. That map is just weaksauceville. And it is rather retarded in cruise too. I can run more advance on 87 octane.
EDIT: Should or more less look like this.
EDIT: Should or more less look like this.
My motor would ping on that timing map on CA91.
Don't know what to tell you then. That map is terrible and it's the cause of high EGT's at cruise. Why do you drop 10* as soon as you go into boost? If you can run 15* at 5k and 156kPa, then you should be able to run 17-18* at 7k and 156kPa. Several reasons for this. If it knocks when you try, you have other problems. Can't tell you what they are, but I'd try to figure it out quick.
Do a compression test and see what you get. What heatrange plugs and what do they look like after a pull through boost? This thing's aftercooled right? (doesn't say in his sig, just making sure)
Do a compression test and see what you get. What heatrange plugs and what do they look like after a pull through boost? This thing's aftercooled right? (doesn't say in his sig, just making sure)
Joined: Jun 2006
Posts: 29,085
Total Cats: 375
From: Republic of Dallas
What's up with your AFR target table? Are you sure the WBO2 is readying correctly? I agree that something is fucked up.
I really recommend det-cans. You will hear detonation that you can't hear with the naked ear.
If you've put a timing light on it, and checked the cams too...then I think you should put a compression test on it. Good luck. Let me know what happens.
my ultra-safe, conservative spark map for nasty track floggin:
I really recommend det-cans. You will hear detonation that you can't hear with the naked ear.
If you've put a timing light on it, and checked the cams too...then I think you should put a compression test on it. Good luck. Let me know what happens.
my ultra-safe, conservative spark map for nasty track floggin:
Don't know what to tell you then. That map is terrible and it's the cause of high EGT's at cruise. Why do you drop 10* as soon as you go into boost? If you can run 15* at 5k and 156kPa, then you should be able to run 17-18* at 7k and 156kPa. Several reasons for this. If it knocks when you try, you have other problems. Can't tell you what they are, but I'd try to figure it out quick.
BKR6Es, IIRC, and it's intercooled, yeah.
Joined: Jun 2005
Posts: 19,338
Total Cats: 574
From: Fake Virginia
Originally Posted by cardriverx
run 40-47 degrees timing in cruise and it should destroy the engine in short order.
how short, cuz I've been running mid 40s at high rpm light load for evAr.
example from a datalog:
77mph cruise
3450 rpm
40-50kPa MAP
15:1 AFR
immeasurable knock
I'm running 40 degrees...
I think my EGTs are around 1200-1300ish during cruise.
Thread
Thread Starter
Forum
Replies
Last Post
StratoBlue1109
Miata parts for sale/trade
21
Sep 30, 2018 01:09 PM








