I'd like to know how some of you guys are tuning highway AFRs. I have mine limited to 16.5 which I believe is limiting my decell enlean, but anyways, that's what it's at and I managed to get 22.4 mph in freezing weather while increasing elevation.
How to you guys push the limits? I'm about to install some thermocouples into my headers to take some data, any ideas as to when you've gone too far? How about frequency of usage. Do you let the motor stay in highway mode a long time or what?
I wonder what kind of milage I would be getting with 2.73 gears and a 6 speed, lol. Better than 30 I'm sure. Anybody know if they make a quick change rear quick change rear for our torque arm cars?

 

ahh i run like 10 different AFR's. i run everything from 13.2 to 16.8 depends on what the cars. doing. also unlike the rest of your ( and like grumpy) i have a turbo car.

As i get closer to boost IE zero vacum i really start richineing things up. ill see if i can put some datalogs together of the various AFR's and my fuel milage. its in the mid 30's high way and high 20's city. depends on how aggresive i am on the throttle

 

Lean cruise has the penalty of adversly affecting engine life.

And with a dissy your limited by cap to rotor timing for spark energy to properly fire the plugs at the timing needed to run lean effectively. While you can get to 50d with a distributor your wasting alot of spark energy just crossing the air gap at that much advance. My best mileage was done at 48d timing, and 16.7:1. That's of course with the 3.8 bore by 3.4 stroke I have.

But, dropping the timing back and adding fuel, increased oil pressure by 5 PSI, and instead of the oil being black as the ace of spades in a thoud miles, at 3K now it still looks as good as new. that tells me that the piston dome temps are passing alot less heat into the oil and therefore there is less carbonizing going on. And it also explains the reason for so many newer cars now spec'ing syn oil. It's getting to be about how much abuse the oil can withstand.

Dropping from 48 to 28, and from 16+ to 13.6 has dropped me to 25ish MPG, and I'll wager that long term, it'll be much cheaper, since the valves will last longer as well as the rings and bearings.

Once it warms up and I can tune the new motor with all the thermal coatings on it, it should be interesting to see how the tune pans out. I think that they may be a key element in MPG.

 

I have noticed that my car will ping with winter gas and required 2 degrees removed from cruising speeds. I've concluded that 92 octane is the min this winter. 87 was fine on long road trips.
I'm going to install a oil temp gauge and run conventional again. Then for "research" I'm going to put in some amsoil 5w-30. I know amsoil will be cooler but I wonder by how much. In our F4i it was as much as 50 degrees! But that was under constant high load mid to high rpm.
I understand the dizzy ignition issues and that's why I've aquired a cran cams high baller CDI. Hopefully this helps with those 3rd gear WOT issues I've been having on and off.
Grumpy, what thermal coatings did you have done? We're getting our motor all dressed up with TechLine Coatings Inc. Headers, pistons, wrist pins, bearings, and CC. We'll be doing a bunch of tests to see if it does anything. Those tests do include a dc electric dyno where we just motor the engine and record the torque translates into pumping losses.
Do you think running 42 degrees of timing and ~16.5 afr is all that detrimental to the engine? I thought highway mode turns on and off with cycles to prevent piston damage.

 

if i now bruce he went to swian tech for coatings. there piston coatings are great. What id realy like to here form him is how much extra power he is able to sqeuzze out with the coating VIa timming and boost ? thats got my mouth watering. I know my honda engine uncoated is a pretty stout performer. but with good coating i think i could find another 50hp by being able to get crazier with AFR's and timing.

 

I'll be interested in hearing what you learn from EGT readings. That is something that I really want to look into for street use, for exactly what you're asking here....How do you know when too lean.... I bet the oil temps will be something to look at here too! Just a semi-educated guess here, but I bet when you run lean for very long the EGT and oil temp will go up to higher than you'd want!

I know from what I've looked at in the ANHT hac that hiway mode does cycle in and out, along with knowing a bit about catalytic converters, I don't think that with a cat (do you have one now? ) you would want to have it in hiway mode too long. Might it may also be something to look at collector temps?

With the fact that hiway mode cycles in and out (at least for $8D) and temps rising when it's in, I can see some use for running EGT (maybe at the collector?) info into the ECM to be a factor in hiway mode operation? I understand this may be overkill, but any time you can do something to be on the safe side of the fence.....

Just my thoughts, maybe they will spark some ideas for someone, or help someone out!

 

Winter fuel has more low end aromatics so yes, typically less timing is needed.

Yep, Techline, the guy that did the coatings was real familiar with them, so we took that option. I did it to keep from putting any more heat into the cooling system then needed. I had a friend do about the same thing with his Syclone and it was impressive about the coolant temps, and EGTs. The Chyro (?), and antifrictional stuff I'm still leery of.

The only high timing my engine's seen was the lean cruise stuff. And I knocked a corner off of one of the piston domes. That's not to say there weren't other contributing factors. 28 PSI would be tough on any cast piston.

In testing with my truck I'm at 34d, and the GN was happy at 28. The stock old carb stuff was at about 40, so at 42 I wouldn't worry toooo much.

I believe the cycling of lean cruise is for converter temps.. Run em too lean too long and they cool off.

 

I really don't care for the fact that they change the fuel so much without the consumer knowing it! I noticed on my daily driver that the last tank was down about 2 MPG.. That really bugs me seeing that the price just went up 20 cents a gallon today! But, I digress from the whole gasoline price thing.......

As for the temps, I understand that the converter temps will be lower, but how will the EGT just out of the head be? I'm thinking it would be higher, but again, just a semi-educated guess!

 

Is EGT even something useable for everyday driving? I would think it would be more useable than for WOT tuning. Again, I'm just thinking aloud.....

 

I'm doing it for different reasons, then max HP. I have about all the HP my chassis and tranny will handle in a reliable manner, as it is. My efforts now are seeing how much I can squeeze out of even a milder tune. By barrier coating the piston domes, combustion chambers and exhaust ports, I should be able to keep the heat in the exhaust, and use that to more effectively spool the turbo. Then possibly run a larger compressor housing, and take advantage of things that way.

I'm actually shooting for making the same HP at 18 PSI, that I used to make at 24.

 

Just a little info about EGTs. They are VERY useful all the time if you can get all the other tid bit info like AFR, oil temps, tps, SA, blah blah blah. When a cylinder cuts out from a fouled spark plug (way rich) you can watch the EGTs drop like a rocket to still hot but not nearly as hot temps. We're talking going from 1400 to 350 in a matter of 2 or 3 seconds. This is why I like thermocouples. Other than the spark plug, a EGT can give you similar data without having to remove the spark plug. Now if only I had a camera inside the CC looking at the piston, plug and valves, .
Keeping the heat in the CC is such a good idea. Not only do you increase your engines efficiency but power goes up since you're building more BMEP (hotter burn). Then what is also great about the coatings is that you don't form hot spots! It's like having high compression without the high compression and requiring less timing. Your BSFC goes down since you can now make more hp with less fuel, it's a win win situation if you can afford it .
When we ran too rich the EGTs dropped, when we run too retarded the EGTs increased. Rich and retarded = hot headers and EGTs higher than ever. Run too much timing and you detonate, EGTs drop way down since the burn is happening so far ahead of the cycle. It's wicked cool doing all of this on a miniture engine that's pumping out nearly 170hp per liter withOUT a poweradder. For anybody interested that's like 950hp from a 350, hehe. Small parts rev friendly = hp and more tuning options. For all of you with 4 bangers and want serious performance, build it to rev or you'll be fighting a loosing battle. For all of you with 8 cylinders, be thankful you have two 4 bangers .
I'm going to do some research on EGTs with water injection and a few other experiments. Right now I'm working on building the new stand for the dyno. We had it moved into a nother building and I wasn't about to go back to a damn water brake!!!

 

You've got a WB?, correct?.

He's an experiment for you,
set the C/L enable HI, and then make a chip where your open loop at 16.5 and see what your mileage is.

 

Oh id prefer to squezze more power out of the same boost. level im at now 14psi. mpore then 14psi seems to break the ring lands with frigtening regularity even with no detonation. Dont ask me talk to honda.

Anyways yeah let me know how that works and how much are the techloine coatings ? did you get a molydisulfide skirt coating as well ??

I was thinkng TBC on the domes Heat rejecting on the unerside with a molydisulfide skirt coat. on the new forged slugs i have sitting on my desk !.

As for the rest of the engine yeah aluminum heads it would be nice to TBC the exhuast ports and chambers. i was thinking about having my intake externally coated in a heat rejecting coating along with my charge pipes.

SO bruce im seriously interested in coating to both improve reliabilty and performance.

Oh what size turbo are you running on the black car now. I found a sleeper of a turbo thats outflow the stock piece if you know anybody lookig for a cheap upgrade.

And if you see anybody looking for the GN headers that some guy used to produce there tube try Y design let me know. theres a michigan fab shop that picked the desing and is making them again!

If you want ill get pictures.

 

The Skirt treatments seems to be more of a crutch to me. The really new stuff has really really small skirt designs.

You might rethink what the wall is at 14 PSI that you're running into. the high RPM operating range tuning of the Honda engine is different then what a low RPM GM would be.
FWIW, I know if I was spinning a motor under boost to 8K, I'd want resolution to as close to that RPM as possible. Decades ago, we had some concerns about being able to move the timing and fuel around at the higher RPM for the 4 cylinders. But, at that time we were limited to blow-thru carbs, and EFI was just beginning.

I have a 60 on it now. It's the largest, reliable, stock appearing one I know of. At this stage a 70 is about my nest step but that blows the stock look.

Ya, I'd like to see the pics.

 

my engine doesnt see over 6500rpm. period. theres just no power u[p there. its an old 12v SOHC a20a1 2.0L 4cyl. Yeah i keep a gfood eye on the fuel and spark needs and no signs of detonation with every measuring means i can find. ive even been to a OEM supplier and calibratrs facility and we looked for acustical knock on one of there big rollers. No dice. no knock. its just that pistons are really weak. the rings lands exspecially. an if you do knock a piston Bam. it breaks. So i got a set or Arias forged pistons just as insurance.

Let me know how the coatings go. and did you want pics of the turbo headers ? ill post pics of my turbo setup as well if your itnerested ?

See if you can get turbonetics to put a hx35 compressor housing and wheel on your t4 setup. the hx35 map is so big that the entire 60-1 map fit inside its effiecny plateua. and the hx 40 nd hx 45 compressors are even bigger. !!!! cheap and easy to find to

outwardly however its about the same overall size as the stock GN trubo.

 

As you go up in RPM, there are some things that get critical.
In a normal stock type engine, the spark pretty much controls the reaction in the chamber for when it begins.
As you get into higher levels of performance, the chemistry changes somewhat in that the temps rise, and the reaction is really ready to happen, so in that case the spark just cascades an event that's really ready to go on it's own. The *go on it's own* is detonation. Now, in a conventional tune, folks usually add some fuel and retard the timing some to stop the ONSET of detonation. But, in some cases, retarding the timing just allows for more time for the heat to build. Tis a fine line as you get to that level.
Looking at what Honda did in the Turbo years of F1 might benefit you.
The trick has always been making the fuel air as reactable as possible. The trick is managing it. How much heat do you want and NEED, and then the guestion is how hot do you want the air, and how hot the fuel. Then in the cal how do you compensate for each?.
If you've looked at my web page, there is at a glance some items that just seem odd, but I did them for a reason.

 

Well grumpy like ai siad. We cant find,meausre,locate knock, signs of knock, results from knock. the ring land just break once you get to say 250hp. this mind you is a 110hp engine stock. i8 mean i can get some use out of it up there in the power levesl but its a limited lifetime. things just break down.

ill post some pics of the damage. If i can find them. And did you want pics of those headers ?

 

Then I'd still look at other items. ie ring gaps.

Yes, I'd like to see the pics.

 

im trying to find pics of the turbo v6 3.8 gn headers. If i cant find them ill go by the shop and snap a few off. sound fiar ?

as for the ring gaps. yeah i think thats most likely the culprit. but im not tearing down a 140k motor etc to re file them. i just keep the boost down and enjoy 225WHp. i cant even get a 6 puc extreme duty clutch to hold with the strongest pressure plate they make. So for now until i get the new flywheel made and the dual disc quarter master 7.25 inch V drive in there im stuck.


these are the ATR headers but they look similar to these. the passenger side header however is diferent. im sure if you wanted something custom or built to your specs they could accomodate most any request. right now there doing a set of twin turbo headers on a GN v6 motor.

heres the pic ( not the headers im talking about but fairly similar) these are ATR's

 

The trouble with the ATR's is that silly V-Band design. I've helped on two cars running them, and both were always a series of on going repairs.
Slip connections are the only way to fly, IMO.

Doing twins on a GN has been a dream of mine, I have two stock turbos sitting here for that very thing. I was thinking of doing my own molds and having a set of manifolds cast. But, stamina has been somewhat down lately.

 

ill find out how much the twin turbo setup on the other GN there doing is. ill get back to you on that. its a pretty intense car from what i saw. Roller cam bearings, big port aluminum head. looks like the block is cross bolted ? im not sure when there gonna be finished but ill try to get pics for you.

As for the AFR's i wouldnt go past 15.8 just to hot.

 

Roller cam bearings?
Or Roller Cam?.
The roller cam stuff I thought faded in the 70s. Seems like they used alot of oil volume to get working right, as I recall.

If it's a 6 bolt main Buick then that's the ne T/A AL block. $3,500 for a rough machined block. And they have some really nice heads to go with it. Kenny D went to over 1,000 HP with the block, and at that level the old heads that were on it failed. But, the block supposedly held it all without a whimper. 1K HP on the first dyno session ain't bad, IMO.

 

no needle rollers. Shes a 4 bolt main block from what i can cofrim but hes iron. sorry i knew it wasnt a ta block. it could be some of the GM hardware from the late eightys early ninites.

Yeah id heard KD had a good sesion with the block. Same problem though theve always had with the 3.8 though. needed 5-6 head bolts 4 just wont cut it. to much localized bore distortion.