105mm to 120mm

[Steve in VC]

First, I am sad to say my stock clutch still holds (no drag race launches - it slipped NA).

The most positive (other than the improved low end torque) is the new PC-Pro settings eliminated the stumble I got at low boost. My red line A/F reads 10 (safe). I will leave it there until I make my pilgrimage to the East (FFS HQ) for a proper tuning this fall (after the heat).

I upgraded the fuel pump, sent the harness to Tom for re-flash, and as I posted earlier was able to change the pulley easily by pushing the car in 5th to get the bolt I was working on to the top, where nothing is in the way.

My butt dyno is pretty numb, so the biggest change is time to red line is much faster, and in those rare occasions where I need too pass, no problem.

The only significant issue was the recommended belt was just long enough that the tensioner pushed the left and right side 1/8" from each other. I traded that in for the 110/115 belt, re-positioned the tensioner (and fought with the belt for a while). No problem. (I checked, no belt sizes in between).

I expect my gas mileage will drop a bit (can't stay out of boost), and my face smileage will go up.

Thanks Tom!

[socal pat]

Man, 105 to 120 is a big jump. I agree that the 10:1 is safe for now, but I bet you'll find at least 15whp once you iron out those AFR's. Where did you end up with your Timing card?

[FormerDatsun510Man]

Glad you like both the new settings and the bigger pulley. I suggest though that if you are reading 10:1 on a wideband at redline, lean it out to at least 11:1 at high rpm. Widebands don't generally read so well below 10:1 and that is rich enough that I wouldn't say it is particularly good for the engine or the cat. Anyway, if you want safe a/f ratios before tuning, I suggest to go for 11:1 Additionally, I suggest the following settings:

E-Cool:
turn up the G-B to 5 lights to give more cooling with this larger pulley

Main Card:
G - 4 to 5 lights (I found that this setting keeps it from leaning out at low rpm)
Y and R - 0 lights (I found it is best to keep these two zeroed out otherwise it skews the fuel curve too much)
Y-B - adjust as needed to hit 11:1 AFR (I figure you would probably need it at 4 lights... remember doesn't have to be exact... +/- 1/2 point AFR is fine)
R-B - 4 lights (makes a reasonably flat curve from mid to high rpm with this setting)

Timing Card:
Super safe settings would be to set G, Y and R at 2,4,4. That combined with 11:1 would be optimal safety before a tune on the dyno.

Bill

[Tom @ Fast Forward]

You are welcome Steve. However, I would like to se it a bit leaner as well. At least 11. Wouldn't want to cook the cat or O2 sensor. If there is any Green, Yellow or Red, (main card) turn them off and check again.

[Steve in VC]

I will defer to the experts and lean it out, 15WHP andd better gas mileage. Works for me.

[Steve in VC]

Glad you like both the new settings and the bigger pulley. I suggest though that if you are reading 10:1 on a wideband at redline, lean it out to at least 11:1 at high rpm. Widebands don't generally read so well below 10:1 and that is rich enough that I wouldn't say it is particularly good for the engine or the cat. Anyway, if you want safe a/f ratios before tuning, I suggest to go for 11:1 Additionally, I suggest the following settings:

E-Cool:
turn up the G-B to 5 lights to give more cooling with this larger pulley

Main Card:
G - 4 to 5 lights (I found that this setting keeps it from leaning out at low rpm)
Y and R - 0 lights (I found it is best to keep these two zeroed out otherwise it skews the fuel curve too much)
Y-B - adjust as needed to hit 11:1 AFR (I figure you would probably need it at 4 lights... remember doesn't have to be exact... +/- 1/2 point AFR is fine)
R-B - 4 lights (makes a reasonably flat curve from mid to high rpm with this setting)

Timing Card:
Super safe settings would be to set G, Y and R at 2,4,4. That combined with 11:1 would be optimal safety before a tune on the dyno.

BillWell....

To get to 11:1, I lowered all the mains except G to the lowest setting and dropped E-Cool to 3. With E-Cool at 5, I was at 10:1.

The transition from vacuum to boost is undetectable - I can feather boost anywhere below 5 pounds with no stumbling.

And, my butt dyno isn't quite as numb, 15WHP, maybe, but definately a change - zoom zoom.

[Tom @ Fast Forward]

Steve, are you running stock injectors?

[Steve in VC]

Steve, are you running stock injectors?I'm running 280's.

[Tom @ Fast Forward]

That's why your settings are lower than Bill suggested. You will probably want to leave ECool where suggested and take more out of Y/B. But I'll leave that to Bill to confirm.

[FormerDatsun510Man]

I agree with Tom there. Move the E-Cool back up to 5 and lower your Y-B on the Main Card as much as you need to so you are back at 11:1. It is quite possible you will end up with the Y-B at only 1 or 2 lights since you are running 280cc injectors.

Bill

[Steve in VC]

The setting Bill suggest got me A/F of 9.6 (bogggggg)

Everything on the main card is as low as possible except G which is at 4.

Everything on the 5th injector is as low as possible except G/B which is 3.

As we discussed in our PM on M.net, I want E-Cool turned up to just non-condensing (as long as the EGT stays balanced).

If this is safe, I can live with it until I make a trip out that way this fall.

I have a knock detector, which seemed to work with the Miata sensor, (but that caused the ECU to throw a CEL). I bought a separate sender unit and it didn't put out enough signal, so I modified the circuit to get more sensitivity. Since then I bought another Miata sensor and will get it set up properly (using a hammer, not 13:1 A/F).

[FormerDatsun510Man]

If you have everything zeroed out on the main card, except for the G, then at this point all you can do is turn down the G-B on the E-Cool so as to get back up to a reasonable AF ratio of 11:1. It seems to me that the likely solution would be to put the stock injectors back in.

Bill

[Steve in VC]

They have been in the bottom of a junk bin - I would be concerned dirt got into them. Me thinks that would be more fatal.

[socal pat]

I'm watching this with interest. I too have 280's with a Walbro 255 and Tom's fuel rail. I recently had Tom re-flash my cards and I have been rich myself. I have had other issues which have prevented me from doing any real tuning, but that was cured just this afternoon in my garage. So in the morning I'll be strapping on my 120 as well. It is amazing the amount of fuel we can put out with this setup. Enough to bog the motor at 15psi. Hard to belive FM sees it necessary to use 550's on 220whp kit?

[rins]

I too had 280cc's first with my 8PSI setup but had to change them back to stock 240's because I got 9-10:1 AFR readings at mid rpm's (everything in PC-Pro was set to 0)

[FormerDatsun510Man]

Consider that the stock 245cc injectors with the stock rail and pump can flow up to about 180rwhp at their limit. With the rail and Walbro pump you can push them a bit higher. We could actually run the standard 105 pulley setup with just that for fueling if we used WI instead of a 5th injector. But a 5th injector is both simpler and more reliable than WI while providing the amount of needed cooling for our hp levels. We use a 500cc 5th injector and that really ups the rwhp limit that we have sufficient fuel. Consider that the 5th injector increases the total fuel capacity by nearly 50% with stock injectors already. Now, we of course don't add that much fuel from the 5th though. For example, with the standard kit making 190-200rwhp, about 20-30rwhp is coming from the 5th injector, which is only about a 1/3 of it's maximum capacity. Turning it up for another 20rwhp on top of this, for making say 210-220rwhp, with no more fuel needed from the main injectors is still well within its capacity. In fact, when running larger pulleys I have found on my car that increasing the amount of fuel from the 5th injector allows one to run less timing retard (with the same AFR as when running less 5th injector too).

Just something to think about. Steve, I think your Miata is safe with 11:1 and 4 deg timing retard with whatever card settings you end up with. However, I think it might be worth your time to bring your stock injectors with you when you come out to Arizona this fall and we can ensure we find which way makes the best power and also drives the best on your Miata.

Bill

[Steve in VC]

280LPH / 245LPH = 1.143
120mm / 105mm = 1.143

Does this mean the 105mm pulley fuel map with the 280 injectors will increase the fuel just the right amount for 120mm pulley.

Leave the 5th injectors set for the 120mm pulley.

[FormerDatsun510Man]

280LPH / 245LPH = 1.143
120mm / 105mm = 1.143

Does this mean the 105mm pulley fuel map with the 280 injectors will increase the fuel just the right amount for 120mm pulley.

Leave the 5th injectors set for the 120mm pulley.

If the 245cc injectors were maxed out the answer would be yes. However, the 245cc injectors are not maxed out on the 105mm setup because we have the 5th injector. This means that as a function of psi, the larger injectors will supply 280/245 x as much fuel with the same PC Pro settings. Since the amount of airflow is proportional to psi (with everything else in the system being the same besides the pulley used), this means that with the same settings on the PC Pro you would be running 280/245 more fuel from the main injectors. Given that you are probably running only 10-15% of the total fuel from the 5th injector, this means that AFR will be significantly richer (as you observed). This is the reason you have to reduce the PC Pro settings so much. Now, if the 245cc were maxed out with the 105mm pulley, the story would be different, though I think we still would have issues in the transitional zones.

That all said, I do have another file available for the PC Pro that we can reflash to give you more range with the larger injectors. This in essense would allow you to reduce the fueling even further on the main injectors so that you can turn the E-Cool back up for better air charge cooling. I guess my point was that if we are having to turn down the duty cycle this far with the 280cc main injectors, it points out that probably the 245cc would be a better match. Either way, we can find out which works optimally when you come out. In the meantime, we can offer you guys both reflashes of the PC Pro to allow better adjustment with the 280cc injectors.

Bill

[Steve in VC]

Bill,

I didn't explain my thought well.

If I use a 105mm fuel map with 280 main injectors, I run rich because the injectors are 14% too big. If Increase the pulley from 105mm to 120mm, the amount of air increases 14%. The 105mm fuel map, which would be lean with 245 inectors, is just right with 280 injectors.

The E-Cool injector stays the same, tuned for 105mm, is too lean with 120mm. It needs a 120mm fuel map.

If this is correct, you have the right maps "on the shelf".


Maybe there is another solution - a 130mm pulley! :drool5:

[Tom @ Fast Forward]

The amount of boost also increases and the cards add fuel for the added boost. If you had the same injectors in both cases, the fuel would be about right as the boost would correct the fuel.

[Steve in VC]

The amount of boost also increases and the cards add fuel for the added boost. If you had the same injectors in both cases, the fuel would be about right as the boost would correct the fuel.That explains - thanks.

[Tom @ Fast Forward]

I think you and Bill and I and several others need to go to Paris and have coffee at "Cafe les Deux Magots" and discuss Life and Miatas. It is on Rue St. Germain right behind Eglise St. Germain. Anybody know why I pick that spot?

I think it is OK to drift a bit now that this thread is solved. :)

[Godless Commie]

I guess it's only because it's germain to the subject..

I'm in, it's only a three hour flight for me:)

[Satisaii]

I think Vivian could be talked into a trip to Paris.

[FormerDatsun510Man]

I'm just afraid that I might not want to leave if I go there. Might need to establish the FFS Europe division :biggrin:

Bill

[Tom @ Fast Forward]

Don't any of you know the significance of Cafe les Deux Magots???? :)

[FormerDatsun510Man]

Well, maybe I could get the award there this year. I'll write a novel of the struggles of turbos vs. superchargers in the Miata world.

I could tell you a lot of stories about the Cafe Du Monde though.

Bill

[Steve in VC]

Don't any of you know the significance of Cafe les Deux Magots???? :)I'll bite, what?

[Tom @ Fast Forward]

First, it is important because I have a beautiful painting of it. :)

Second, because I always found the name to be funny for a café. Deux magot literally translates to 2 magots. Intended meaning is 2 eggs.

Third because it was the favorite place for itellectuals such as Simone de Beauvoir, Jean-Paul Sartre, Ernest Hemingway and Pablo Picasso to sit around, drink coffee and contemplate their navels; as well as mundane things like existentialism. I think we have an equivalent group of philosophers. ;)

[FormerDatsun510Man]

They have it on wikipedia.

http://en.wikipedia.org/wiki/Les_Deux_Magots

[Godless Commie]

I was just being subtle..

[FormerDatsun510Man]

I was just being subtle..

What do you mean? J/K :biggrin:

Bill

[Steve in VC]

Just something to think about. Steve, I think your Miata is safe with 11:1 and 4 deg timing retard with whatever card settings you end up with. However, I think it might be worth your time to bring your stock injectors with you when you come out to Arizona this fall and we can ensure we find which way makes the best power and also drives the best on your Miata.

BillThe weather has stayed at 85F. I moved my air cleaner behind the fog light, so my intake is very close to ambinet. I dialed out all the timing retard - no detonation. I'll keep a close eye on my detector (ears are shot).

I will retard timing before I cross the desert. I will bring the old injectors.

Enjoy,
Steve

[FormerDatsun510Man]

Glad to hear you have it running well! The 11:1 AF and 4 deg timing retard is a combination that I am sure would be extra safe, so it doesn't surprise me you can remove the timing retard with 93 octane. However with the AF leaned out to a max power setting in the 12:1 range I expect you may need a couple deg timing retard especially when you are out in AZ with the wonderful 91 octane available :biggrin:. On the other hand, if we are able to reduce the main injectors further (possible using the stockers reflowed) so that we can turn up E-Cool to its optimal setting I think we may be able to run no timing retard even on 91 octane. Time will tell :)

Bill

[Steve in VC]

Parts Group has a good used set of '00 injectors form my '00.

They have an almost new set of '01's (grey), but I assume they are not the right flow rating. Can anyone confirm that?

[Tom @ Fast Forward]

Correct. Yours are 240cc and the 01 is 280cc.

[Steve in VC]

Glad you like both the new settings and the bigger pulley. I suggest though that if you are reading 10:1 on a wideband at redline, lean it out to at least 11:1 at high rpm. Widebands don't generally read so well below 10:1 and that is rich enough that I wouldn't say it is particularly good for the engine or the cat. Anyway, if you want safe a/f ratios before tuning, I suggest to go for 11:1 Additionally, I suggest the following settings:

E-Cool:
turn up the G-B to 5 lights to give more cooling with this larger pulley

Main Card:
G - 4 to 5 lights (I found that this setting keeps it from leaning out at low rpm)
Y and R - 0 lights (I found it is best to keep these two zeroed out otherwise it skews the fuel curve too much)
Y-B - adjust as needed to hit 11:1 AFR (I figure you would probably need it at 4 lights... remember doesn't have to be exact... +/- 1/2 point AFR is fine)
R-B - 4 lights (makes a reasonably flat curve from mid to high rpm with this setting)

Timing Card:
Super safe settings would be to set G, Y and R at 2,4,4. That combined with 11:1 would be optimal safety before a tune on the dyno.

BillI installed a good set of the stock 240 injectors (in place of the 280's), and set the PC-Pro's & timing the above, A/F ratio went to 10.

I backed off the mains with little effect. I backed off the E-Cool and got to 11.5.

I didn't play with timing as it was 100+F yesterday, and I am rebuilding my Knock sensor, and I disconnected my ScanGauge while adjusting the clutch (The ACT stage 2 engages pretty close to the floor).

When I replaced my injectors, I noticed 3 of the 5 allen bolts holding the top of the intake were gone. I put in new ones with more blue locktite, and re-locktighted the other 2. Boost is at 15 with the 120 pulley on a stock 2000.