URD 7th Injector Tuning Guide
- Thread starter shootmymime
- Start date
masphx
New member
So I'm still trying to get a hold on this tuning thing. Something is not clicking in my head about it for some reason. I have the stock tune loaded on and I'm able to record the r4 software and the AFRs. I understand the open loop tune but it is the closed loop I'm not understanding. I have a 98 4Runner so my understanding I can tune in closed loop. Every site mentions this but none say how to do it. Also not understanding the timing advance in closed loop. Right now I'm trying to find a way to record my timing advance fuel trims and closed/ open loop status to my computer but that is turning out to be a struggle.
4Reak Show
New member
Pretty much closed loop is any time you're just driving around while warmed up and NOT at wide open throttle. Hence, a majority of the time. The fancy URD box will compensate for any additional fuel given to the engine by telling the main computer that it ISNT enrichening. (If it didn't tell the main computer this, it would simply scale back the main injectors to compensate and you wouldn't actually increase the overall fuel mixture. That's why you tapped into the O2 sensor signal wires upon install). So basically, when you're looking at your chart of values, you want to add fuel in the lower boosted areas since GENERALLY that's the closed loop range. At least that's my understanding. Also, turning down the overpressure setting within the URD software will tell the URD box when to start to enrichen the mixture (and therefore lie to the main computer).
For example, my driving style is very mild by comparison and I normally only float around 0-5 PSI of boost when I'm getting on it (only like 1/2-3/4 throttle) So I turned my "overpressure" setting down to 1psi so it will start the enrichment process at 1 psi and above. Any value I put into any cell at the 1psi range will be automatically compensated to the main computer and should appear on the AFR reading as a rich mixture overall.
The timing is a lot more tricky. It's hard to have everything refreshing and appearing at the exact same time. The goal is to have like 20 degrees at any given time of advance if I'm not mistaken(?) So if the main computer is showing 15 degrees at a particular area, is has retarded (delayed) the ignition by 5 degrees. And you would then put a 5 into that area on the chart, so the URD can again lie and tell the main computer everything is groovy and it should then float at 20 degrees again on the main computer's data reading.
It's not the best plan, but I only increased my timing retard based on how I drive, how it feels and how it sounds. When it's pinging, that's a no-no and needs to be corrected. Simply have the r4 software live and showing what cell range it's in when it pings and increase the numbers in that cell (and slightly around it to buffer) until it no longer pings.
Also when you change a cell's value don't forget to actually "write it" to the URD box as a DIFFERENT CUSTOMER/FILE NAME so you can still revert back to the original chart. That took me a few tries to grasp.
Good luck
For example, my driving style is very mild by comparison and I normally only float around 0-5 PSI of boost when I'm getting on it (only like 1/2-3/4 throttle) So I turned my "overpressure" setting down to 1psi so it will start the enrichment process at 1 psi and above. Any value I put into any cell at the 1psi range will be automatically compensated to the main computer and should appear on the AFR reading as a rich mixture overall.
The timing is a lot more tricky. It's hard to have everything refreshing and appearing at the exact same time. The goal is to have like 20 degrees at any given time of advance if I'm not mistaken(?) So if the main computer is showing 15 degrees at a particular area, is has retarded (delayed) the ignition by 5 degrees. And you would then put a 5 into that area on the chart, so the URD can again lie and tell the main computer everything is groovy and it should then float at 20 degrees again on the main computer's data reading.
It's not the best plan, but I only increased my timing retard based on how I drive, how it feels and how it sounds. When it's pinging, that's a no-no and needs to be corrected. Simply have the r4 software live and showing what cell range it's in when it pings and increase the numbers in that cell (and slightly around it to buffer) until it no longer pings.
Also when you change a cell's value don't forget to actually "write it" to the URD box as a DIFFERENT CUSTOMER/FILE NAME so you can still revert back to the original chart. That took me a few tries to grasp.
Good luck
4Reak Show
New member
You can do whatever you need to to obtain the proper AFR, based on how you drive and what you're trying to obtain. Every truck seems to run a little differently and need different areas of improvement. Remember, it's unlikely it will ever feel as effortless as big Chevy V8 in my experience.
shootmymime
New member
Yes. Adjust your values, little by little in smooth increments. Open loop starts around 3000 rpm. So try to stick to fuel numbers around there. You should not need any fuel below 1psi.
I'm quoting you here because I didn't want to quote your monster message. I agreed with everything in it BTW.
Timing is meant to stay at 20deg at full throttle, You have it exactly right. Viewing the timing (I'm using an ultra gauge) shows some number. (16). You need to find the exact place where it is reading that value on the R4 software and it should be 4 or close to there. Thus making your timing at 20.
You guys got this!!
shootmymime
New member
I have noticed that the 2.2 brings on boost so fast that the computer is not able to compensate fast enough from that initial part throttle to 1-2 maybe 3 psi in an instant, that is where hesitation happens at times.
We should also try and add some timing at the lower rpm to prevent low rpm ping high boost. I just got my truck figured out. (My wiring was installed incorrectly, My mistake). So I am now starting to figure out what other people were talking about.
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We should also try and add some timing at the lower rpm to prevent low rpm ping high boost. I just got my truck figured out. (My wiring was installed incorrectly, My mistake). So I am now starting to figure out what other people were talking about.
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shootmymime
New member
so an update, my truck ran great on the highway for a couple days, then i went to moab and on the way home i noticed my arf were not in the mid 11.s like i had in the past, but were not in the mid 13s
so i guess now my wiring was not the same, i got the correct wiring info from URD and i had to change my maps quite a bit to get the fuel i need. now i am in the 12s but i still need to get into the 11s
more work on this POS!
so i guess now my wiring was not the same, i got the correct wiring info from URD and i had to change my maps quite a bit to get the fuel i need. now i am in the 12s but i still need to get into the 11s
more work on this POS!
shootmymime
New member
I got around to changing my tune and making some adjustments. At my 4,500 ft elevation I would only see 6-7 psi with my 2.2 pulley. So I decided to throw on the 2.0 and see what happens.
My numbers are good. (Little rich). And timing looks nice.
My numbers are good. (Little rich). And timing looks nice.
Last edited:
JayRolla
New member
Adding low rpm timing will make detonation worse not better.
4Reak Show
New member
Traditionally, you're totally correct. But I think he means "adding more retard" since that's how the URD 7th system works: the numbers you increase delays (or retards) the timing.
shootmymime
New member
Jayrolla you are correct. But that's not how the 7th injector works. (It's kinda backwords)
4reak show is correct. The way the 7th injector system works.
You add values with the tune which retards the timing.
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JayRolla
New member
OMG, I guess you may be right and thats what he meant. Might be very confusing to someone just learning out how to tune. By adding timing retard he is removing timing to help fight knock.
4Reak Show
New member
Indeed. And for the record I did have to add quite a bit of retard on the lower end to combat knock. Only like 100' elevation and summers in the 90-100's so it got bad sometimes. Plus being a manual, I'd be at like 2,000 RPM in some gears to accelerate and 2-3K rpm seemed to need quite a bit of retard to stop be knocking.
Sucks, cuz you can feel the power difference, but at the price of NOT blowing up my motor, I'll take it. Never gonna be a race car.
Sucks, cuz you can feel the power difference, but at the price of NOT blowing up my motor, I'll take it. Never gonna be a race car.
shootmymime
New member
But good catch with both of you. Made me think for a bit.
It's completely different the timing my 71 mustang.
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It's completely different the timing my 71 mustang.
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Last edited:
JayRolla
New member
ECU controlled timing is way different. In my DSM I can set base timing just like in an older motor and the ECU takes over from the base timing set with the timing light. Which is cool because most newer cars are only controlled by the ECU and not able to adjust base timing at the CAS.
JayRolla
New member
E85 tune or meth injection. THen you could most likely add timing (removing retard) to get that power back and some.
On my DSM 91 pump gas I could run at most 20psi of boost and 14* max timing. After e85 I could run 36+psi and 22* max timing. Same car and setup. Pump gas dynoed 300whp, e85 400+whp.
shootmymime
New member
I would like to get a tune for us 7th injector guys on e85. It's something I've through of for a while. But never really gone any further than the thought.
Could you mix 85 and 91 (generally speaking unknown of a ratio ATM ). Afr may go up a hair but octane would be higher.
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JayRolla
New member
Yes you can mix it. Its what the mazda/ford guys do with the direct injection fuel system since upgrading the system is pretty much out of question. So they do a 70/30 mix. You must do it perfect each time or you will need to retune. And yes you need a tune directly for the e85 mix as your car will run super lean at that ratio.
Its easier to just tune it for e85 if you car can handle it. Would need fuel pump and injectors that can handle roughly 30% more flow.
shootmymime
New member
What's the 70/30 mix? What to what? I have heard 30% more fuel needed.
With my 7th injector system, walbro 190 I guess I'd be fine. I'd probably throw on the stock pulley or 2.2 to test 85. Sure wouldn't run the 2.0 like I am now.
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