u r sofa king we tah did

ok let me start off by telling you what i have. its an 89 irocz with a warmed 350, 24# accel injectors, car was originally 2.77 rear, now its 3.42 with an 700R4. (about to be t56 but im gonna start burning now with the 700R4 to get the hang of it).

first question is, with the 24#ers im running a bit rich, and my BLM numbers are in the 117-119 range normally. now if i have read this right, i need to change my injector constant first and foremost until i get the BLM to stay right around 128 at light cruise? or idle?

with the gears being changed to 3.42, i am able to bring the advance up to full advance faster than the stock 2.77 chip without running into detonation right? not meaning upping the total advance, just faster transition to full advance.

on highway mode, is there a certian amount of time that you should stay in highway mode? i see a time limit setting, just wondering if there is a safe point and a danger point.

lastly, glenn i noticed in a search you said you enable PE at 50% throttle to make it seem like vacuum secondaries are opening, are you still doing this and how do you like it?

thanks for your time guys, im gonna be asking alot of questions in the next 2-3 weeks so dont beat me with a stick too hard if i ask a dumb question.

Grumpy

What seems to be working best for me lately, is using the injector sze, to get the BLs close to 128 at cruise. That will at least get the car drivable. Then I fudge the battery volatge correction to get the idle close. Then attack WOT.

Lately, I haven't been bothering with highway modes, well other then AFR. Clever use of timing will get you as much timing as you want in the main spark table.

Gearing and converter go hand in hand. The real problem is the gear spacing with the 700R4 that just limits what you can run. I often have to pull alot of timing out below the stall speed of the converter just to min wheel spin. Then just a note the timing shouldn't change alot from peak torque to max HP, though getting slightly richer between those two points.

Any more, and I'd have to shoot you.....

Grim Reaper

I'm with Bruce on the methodology for "starting" your adjustments for larger injectors. Fuel pressure is a key concern too. I have found the "flow characteristics" are not linear as you increase fuel pressure. Higher fuel pressure has a higher effect at high loads and least effect on low loads. I also use Bruce's method of adjusting Constant first to "ball park" and then work on idle via Batter Correction.

As for gearing, you should be able bring on the spark advance a little sooner, but it is really something you need to "test, test and more test". Over 75% of all my eprom "burns" have been spark related...just to give you a hint. Let the engine tell you what it wants, and it will go quicker.

For the Highway Mode, I suspect you are talking about the timers. Basically there are two. I am going off memory, so bear with me if my titles are slightly incorrect. There is one timer for how long the "Highway Mode Cycle" will run, before it "resets". Stock it is around 60 seconds. Leave that alone.

Then there is a delay timer. This is the amount of time Highway is "delayed" once all the conditions are met (including the 60 second timer). Stock this is set to "10 seconds". If you leave this unchanged, you will run in Highway Mode for 60 seconds, then drop out for 10 seconds. I've set my "delay" to 0.

Now, there is some debate as to whether this is a "good thing to do". One group says that you constantly running Highway Mode will result in premature death to the cat. Thus you need to "cycle" the Highway Mode on and off to ensure you don't burn it out.

I have been running with the delay at 0 for over a year and thus Highway Mode will CONSTANTLY run. So far there doesn't appear to be any problems with my cat, but only time will tell. I think that if you have good mixtures, then you can try running constantly in Highway Mode but don't go too lean on the AF ratio. I live in a mountainous area, so my Highway Mode gets cycled "naturally" just by driving. But if you live in a "flat area", you may wish to cycle your cat.

Lastly, I am still using 50% @ 1,200 rpm and as the RPMS go up I decrease mine with it invoking at 35% @ 4,800 rpm. This is something you need to play with and find out what you like. I believe Bruce mentioned that he invokes his at 16% at all rpm levels. Bruce does have a turbo so he has different tuning concerncs. But this is one of those areas I think you need to play with and find out what you prefer. What I like and what you like may be entirely different.

Have fun with the tuning. I'm currently experimenting with "lower grades of gas" as the cost of 94 octane is 20-25% higher than 87. That is a big incentive to tune my car for "at least" being able to "cruise" with 87. Because I do use a "piggy back", I am thinking of having one for 87 (highway travel) and 94 (performance). Ultimately, I would like to figure out how to get the power out of 87 as I do with 94. I definitely have to lower the spark advance for 87 at any loads > 70 Kpa or I ping like crazy. (I disabled the Low Octane Routine which would normally take care of this, but this routine also contributes to "inconsistent performance").

Everything is a learning experience.

Grumpy

the bric converters are alot more robust then the pellet and I'd venture a guess the two are being talked about at the same time. I'd just use an easy *break out* of lean cruise so not to risk being lean under ANY load other then flat road. Mine phases out even just going to 75. I have full lean at 65 and lower, 70 is also just parshal, and like I said gone at 75. thou, my cal is so close there really isn't a big change MPG wise.

87 to 94 ain't all about octane.
The biggest difference is the additive package. From what I've been able to see plug wise, dunno now the chemistry, and that's like CIA material. Even in race gas they won't tell you the EXACT brew, just the physical properties.

You can spend alot of time on Reed Vapor Pressure and blow off temps of the aromatics, and when done, you'll just better understand why you can't undo the chemistry boundries. Well if you a chemist you might come up with your own additive package, but that's sure alot of work.

It's getting border line, but up til recently the difference is fuel prices was always recoverable in lower maintance. But the stuff is turning to real dodo lately.

operator is asking for another 65 cents so I guess time to hang up......