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Tuning for 80's and 100% ethanol

SgtMarshal

SgtMarshal

Active member
[FONT=&quot]I installed a set of 80 lb injectors and filled my tank with E100. I was confident in my tuner until he said my IFR should be right, then another tuner said to use a different IFR and it worked. I thought I had a vacuum leak because my fuel trims were 16.4. if I did have a vacuum leak, changing the IFR would have no affect, right?[/FONT]
 


I'm pretty sure it would make a difference. If you decrease the IFR, you would richen up. I do most of my tuning in open loop, and I know for sure you can tune away a vacuum leak. You don't want to do that obviously.

Easiest way is to smoke it for a leak, but if you just stick a rubber gloves over the throttle body and blow a little air into a vac line, you can make the glove inflate a little. It should pretty much stay inflated when you plug the vac line you blew air in. Well, unless you have a big cam. If it immediately deflates, you have a leak.
 
Not unless you know how to tune offsets. What I did is tune stock injectors with stock settings. Then plug in new IFR and tweak it until trims or AFR error(using wideband) was close. I still had to retune the MAF. I spent a lot of time researching how to get the correct injector values, but eventually gave up and stayed with stock offsets. Unless you get ID injectors you won't ever have the right values. I really don't think it makes much difference because our pcm is pretty limited compared to newer V8 computers. You can get a solid tune just changing IFR for 80's. I recommend open loop MAF tuning if you have a wideband. I had a lot of trouble at first because of l any injectors, vac leaks and a bad fpr. But now I can open loop MAF tune from a crappy MAF table to within 2-3% in an hour. The guide is on hptuners v6 engine tuning forum in a sticky.
 


it was the tune. and i forgot to plug the vacuum line to the fuel pressure regulator. fuel trims are pretty close to 0, which surprises me because I haven't made any maf adjustments.

I built a stethoscope for the engine and had a friend ride shotgun with the computer in his lap with the ear muffs on to listen to the engine and he said he could hear detonation, only on one pull, the next pull was clean and he didn't hear anything

on a side note, i think i'm spraying too much water. I will have to swap nozzles for the medium or turn the water spray off. car felt like a turd at full throttle.
 
You'll get detonation from being too rich, as well. First time I tested the meth kit, medium nozzle, it fell on its face and knocked. I pulled fuel from WOT and have stepped up to the large 500cc nozzle, pulled more fuel, and it runs great. These Heaton love the spray. You can go to a larger nozzle than is recommended since we are running it through a furnace of a blower.
Good read:

Water / Meth Injection with Roots Superchargers [Archive] - K20A.org .:. The K Series Source . Honda / Acura K20a k24a Engine Forum
 
Soon as I get my brake and fuel lines fixed I'm gonna make me some of those knock muffs. I'm curious how much false knock these have. That knock muff build you posted said that once you start modding your car, stock knock sensors aren't as reliable since the sensors were tuned around the stock engine.
 
Oh, well it would help if I knew what I was talking about, lol. Sorry I just assumed you were using meth mix. I had just installed the 500 from the 250 right before my brake line blew.
 


that article was really interesting. makes me wonder how much power I would be making with a dual nozzle and 50/50 water/methanol. since i'm spraying water only I think I need to decrease the nozzle size.
 
bandook said:
Oh, well it would help if I knew what I was talking about, lol. Sorry I just assumed you were using meth mix. I had just installed the 500 from the 250 right before my brake line blew.
Click to expand...


just jump to the large 1000 cc nozzle since you are spraying 50/50.
 
I may. I'd have to order the nozzle. So your afr doesn't go rich or lean when you are spraying? Are you using a progressive controller? I was curious so ive been reading up on spraying just water, and some say they had to tune the bog out. Others say no. It just seems that you would be at least a little rich since the water would be taking up air volume. Dunno
 
I wouldn't jump to the 1000cc nozzle if you are going to spray water only. spraying water is supposed to intercool the blower, but also cool the combustion chamber. I do use a progressive controller. its the aem kit.

mine is running rich right now but I think it's cause I need to adjust the maf.

since you are on E85 you already have some charge air cooling, so I wonder if you would need to use the small nozzle. but cooling the blower is a good thing.
 
Everyone needs to remember if your tuning gasoline you really need to be able to watch wot afr, tuning rich then pulling fuel back is much safer. I honestly havent seen an engine knock overly rich and I've Dyno tuned and strip tunes many over the years.
Under boost most engines make best power in the 10.5-11.5 afr BUT I've had several engines with high 12 to low 13 afr make near perfect pulls.
The water/meth can help an engine with preignition issues while making more power.
Engines respond better when air is cool and damp.
Thus the reason for intercoolers.
We had one of the 775bbc on Dyno and it was former pro mod engine, it was dual carb with massively ported big chief heads and 15.7-1 compression, but was spinning only 200-210psi on dynamic compression test due to camshaft overlap.
BUT above 4800 it had issues, we traced it to the engine detonating over gas quality. We installed a Snow water meth unit and tada the engine woke up and ran well even on down to using 89 octane. We tried E85 carbs but E85 in our area is so weak since they dropped the spec on E85 from E70 to E51.
The inconsistent nature of E85 is so bad it's limited value right now.
But on the Dyno I chose a conservative timing curve, then bring in the fuel till it tops out on power, then add a bit more timing then fuel and so on. We then keep working fuel and timing curve till we get best power. I also like to check about pulling timing for track tuning. If engine still makes power ok but bit less torque curve for bad tracks and such.
I had one customer that ran his car tuned back a bit, and kept the higher power setting for last ditch effort in face offs.
 


MonzaRacer said:
Everyone needs to remember if your tuning gasoline you really need to be able to watch wot afr, tuning rich then pulling fuel back is much safer. I honestly havent seen an engine knock overly rich and I've Dyno tuned and strip tunes many over the years.
Under boost most engines make best power in the 10.5-11.5 afr BUT I've had several engines with high 12 to low 13 afr make near perfect pulls.
The water/meth can help an engine with preignition issues while making more power.
Engines respond better when air is cool and damp.
Thus the reason for intercoolers.
We had one of the 775bbc on Dyno and it was former pro mod engine, it was dual carb with massively ported big chief heads and 15.7-1 compression, but was spinning only 200-210psi on dynamic compression test due to camshaft overlap.
BUT above 4800 it had issues, we traced it to the engine detonating over gas quality. We installed a Snow water meth unit and tada the engine woke up and ran well even on down to using 89 octane. We tried E85 carbs but E85 in our area is so weak since they dropped the spec on E85 from E70 to E51.
The inconsistent nature of E85 is so bad it's limited value right now.
But on the Dyno I chose a conservative timing curve, then bring in the fuel till it tops out on power, then add a bit more timing then fuel and so on. We then keep working fuel and timing curve till we get best power. I also like to check about pulling timing for track tuning. If engine still makes power ok but bit less torque curve for bad tracks and such.
I had one customer that ran his car tuned back a bit, and kept the higher power setting for last ditch effort in face offs.
Click to expand...


but have you run 100% ethanol?
 
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