IbanezDan51
Well-Known Forum User
The 280Z tank is supposedly better because of its extra baffles. I think its one of those things, you try it, see if it works, if you have issues resolve them later.
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Speeduino installation
- Thread starter jonbills
- Start date
The 280Z tank is supposedly better because of its extra baffles. I think its one of those things, you try it, see if it works, if you have issues resolve them later.
tyroguru
Club Member
OK - thanks. I've certainly seen a number of EFI installations with 240Z tanks but I guess we don't know how successful they each are under different driving conditions. As you say, suck it and see with this.
I've got two pumps, a low pressure one by the tank and high by the Swirl pot. When the tank is lower than 1/4 I do hear the low pressure pump going dry briefly on corners and roundabouts. But the Swirl pot is always full and the HP pump sources from there.
Jon the one thing I avoid on pain of death in my z ownership is adding up what I’ve spent! Best live in ignorance on that front.
This is seriously impressive stuff JB! Great work. Now you have to put the kit together and sell a turnkey solution to the rest of the Z world.
One question, did you ever solve the knock sensor puzzle? Did you manage to get it working and does speeduino have the ability to take a knock signal and act on it?
This is seriously impressive stuff JB! Great work. Now you have to put the kit together and sell a turnkey solution to the rest of the Z world.
One question, did you ever solve the knock sensor puzzle? Did you manage to get it working and does speeduino have the ability to take a knock signal and act on it?
johnymd
Club Member
I’ve run EFI on several Zed’s and never had an issue with the 240z tank. If you just think about what you are using the old tank for then it becomes obvious.
The existing tank is just backup storage for you engine fuel source which is the swirl pot. The swirl provides a constant supply of fuel to your engine and is shaped so the outlet will always provide fuel when cornering, braking and accelerating. The zed tank just keeps it topped up so if fuel supply from this tank is interrupted for several seconds (cornering/braking) it doesn’t matter as the swirl pot will have a reserve of fuel to keep you going.
The existing tank is just backup storage for you engine fuel source which is the swirl pot. The swirl provides a constant supply of fuel to your engine and is shaped so the outlet will always provide fuel when cornering, braking and accelerating. The zed tank just keeps it topped up so if fuel supply from this tank is interrupted for several seconds (cornering/braking) it doesn’t matter as the swirl pot will have a reserve of fuel to keep you going.
Yeah I don't normally add up what things cost. I'd been telling myself I'd probably only spent a grand or so!
Speeduino itself doesn't support knock detection, but they are apparently working on a standalone knock sensor. (I think with the idea that Speeduino can use it as an input)
I'm not sure I'll bother, I've had no hint of knock since I've been using the P90.
Speeduino itself doesn't support knock detection, but they are apparently working on a standalone knock sensor. (I think with the idea that Speeduino can use it as an input)
I'm not sure I'll bother, I've had no hint of knock since I've been using the P90.
Today I realised my throttles weren't balanced well - #1 was opening before #2 and #3 last, so adjusted the linkage.
I also made the AFR Table a couple of points richer everywhere, having read a bit more about power and AFR.
Because of the changes, I had to retune it. It seemed to take one or two out pretty much everywhere in the VE table.
Not sure if that makes sense to me, but it must be right.
The VE table's quite pretty
X is RPM, Y is Throttle Position and Z is fuel volume required.
It sort of makes sense, like below 5k rpm or so the throttle opening is only the limiting factor upto about 35% open, after which the engine has all the air it can use at that RPM and more throttle doesn't make a difference.
I also made the AFR Table a couple of points richer everywhere, having read a bit more about power and AFR.
Because of the changes, I had to retune it. It seemed to take one or two out pretty much everywhere in the VE table.
Not sure if that makes sense to me, but it must be right.
The VE table's quite pretty
X is RPM, Y is Throttle Position and Z is fuel volume required. It sort of makes sense, like below 5k rpm or so the throttle opening is only the limiting factor upto about 35% open, after which the engine has all the air it can use at that RPM and more throttle doesn't make a difference.
From what I’ve read / understood, 11.5 AFR is great for racing and best rich torque while keeping engines cooler on long straights; but ideal target for balance of power and rich torque is between 12.2-12.8 depending on who’s publication you read.
Seriously in awe of your efforts on this project buddy - you are not just learning but engineering your way through it! [emoji106][emoji106]
Seriously in awe of your efforts on this project buddy - you are not just learning but engineering your way through it! [emoji106][emoji106]
Thanks Ali. I'm still a bit leaner than that, I've aimed it at 13.0. Maybe I should reset again for 12.8? I'm inclined to get down to Northampton motorsport and get it on their dyno and see what they think.
13.0 isn’t too shabby either Jon.
The RR is the way forward and the only way you are going to know for sure. What does that cost you? My local place does £100 a power run or £150 an hour off peak.
I know conventional Z wisdom says you can go to 34 - 38 degrees of advance on the L series but what a few experienced heads (old skool race mechanics) have told me and been consistent about is: get the mix Bob on and don’t get greedy with timing - unless you are racing, the 2-3 degrees extra is not going to make power that you will feel off a rolling road but will save your engine in the long run.
This is an interesting article on the topic too ..
https://www.hotrod.com/articles/innovate-air-fuel-ratio-meter/
This is very long but educational ...
https://www.enginebuildermag.com/2008/07/carburetor-tuning-the-airfuel-equation/
The RR is the way forward and the only way you are going to know for sure. What does that cost you? My local place does £100 a power run or £150 an hour off peak.
I know conventional Z wisdom says you can go to 34 - 38 degrees of advance on the L series but what a few experienced heads (old skool race mechanics) have told me and been consistent about is: get the mix Bob on and don’t get greedy with timing - unless you are racing, the 2-3 degrees extra is not going to make power that you will feel off a rolling road but will save your engine in the long run.
This is an interesting article on the topic too ..
https://www.hotrod.com/articles/innovate-air-fuel-ratio-meter/
This is very long but educational ...
https://www.enginebuildermag.com/2008/07/carburetor-tuning-the-airfuel-equation/
Modern cars achieve 16 on the cruise for fuel economy, so in some respects not a bad thing with a bit of vac advance timing but otherwise you may be cruising a little hot imho. Does it matter? I genuinely don’t know enough to say either way, but my gut says you may be stressing your valve edges with very hot gas passing at high velocity / frequency.
Someone with better knowledge of these things and educate me / us on that front.
Someone with better knowledge of these things and educate me / us on that front.
Thanks Mike, I think the main difference between Speeduino and MS2 is that Speeduino is still being actively developed in terms of both hardware and software.
I'm really impressed with it, but I've got not experience of others [emoji28]
I did recalibrate the TPS, but it wasn't out - TPS is on body #1 which was leading #2 and #3, so the adjustment brought 2 and 3 in line with #1 if that makes sense.
perfect sense , sometimes the idle changes and needs a throttle stop change which can then lead to a tps adjustment. i will have a look on the diy efi site when i get time.
you have gone past where i stopped as i never got to a wideband and autotune (ran well) , thats for my next attempt
and in case anyone is wondering it was a ford zetec rather than a Z
you have gone past where i stopped as i never got to a wideband and autotune (ran well) , thats for my next attempt
and in case anyone is wondering it was a ford zetec rather than a Z
The last week or two, I've been fretting a bit about injector open time. I left it at the default of 1.0ms since the beginning, which is said to be "close enough" for most injectors. But with a pulse width of only 1.5ms or so at idle, being a few % out on the dead time can make a difference.
I asked Bosch on twitter, who helpfully said that it was proprietary information so they couldn't possibly tell me.
So yesterday I had a go at calculating it myself.
In tuner studio, there's an engine settings page where you tell it about your engine and injector size, and how many times to squirt per cycle.
You can also see when the engine is running a value called "pulse width", which is how long (in ms) current is applied to the injector each squirt. Pulse width minus open time is actually how long fuel is squirted for.
So, the theory is then that if you hold the engine at a set rpm with a set AFR (say 3000 and 14.0) then the actual fuel delivered per cycle will be the same whatever squirts per cycle is, and you can calculate your injector open time from the differences in the pulse width.
I tried this with 2 and 3 squirts with 1.0ms set.
With 2 squirts, my pulse width is 1.65ms. Take away the 1.0ms for open time, then I've got 2x 0.65ms squirts per cycle = 1.3ms of fuel.
With 3 squirts, my pulse width is 1.425ms.
Take away the 1.0 again and that's 3x 0.425 = 1.275ms of fuel.
Close but not the same.
You can then do the calculation:
openTime = [NumOfSquirt(a)*PulseWidth(a) - NumOfSquirt(b)*PulseWidth (b)]/ [NumOfSquirt(a) - NumOfSquirt(b)]
and I get the answer 0.975 is my open time. So take that Bosch, I've revealed your secret
I asked Bosch on twitter, who helpfully said that it was proprietary information so they couldn't possibly tell me.
So yesterday I had a go at calculating it myself.
In tuner studio, there's an engine settings page where you tell it about your engine and injector size, and how many times to squirt per cycle.
You can also see when the engine is running a value called "pulse width", which is how long (in ms) current is applied to the injector each squirt. Pulse width minus open time is actually how long fuel is squirted for.
So, the theory is then that if you hold the engine at a set rpm with a set AFR (say 3000 and 14.0) then the actual fuel delivered per cycle will be the same whatever squirts per cycle is, and you can calculate your injector open time from the differences in the pulse width.
I tried this with 2 and 3 squirts with 1.0ms set.
With 2 squirts, my pulse width is 1.65ms. Take away the 1.0ms for open time, then I've got 2x 0.65ms squirts per cycle = 1.3ms of fuel.
With 3 squirts, my pulse width is 1.425ms.
Take away the 1.0 again and that's 3x 0.425 = 1.275ms of fuel.
Close but not the same.
You can then do the calculation:
openTime = [NumOfSquirt(a)*PulseWidth(a) - NumOfSquirt(b)*PulseWidth (b)]/ [NumOfSquirt(a) - NumOfSquirt(b)]
and I get the answer 0.975 is my open time. So take that Bosch, I've revealed your secret