13 replies to this topic

[Kyle Burkhardt]

Been doing alittle research and need to confirm my understanding is correct. I have a 99. Right now, I'm not looking for that last 2hp so I'm not interested in dyno tuning. I'm looking for a standard setting for FP and timing that produced the most safe hp without tuning on the dyno. It looks like the FP set by the modified OE regulators for sale on the net (52-54) and 14 degrees should do the trick. Any other suggestions?

Oh, and I'm not running a A/F guage now (but will once I go AFPR and spend the coin on tuning), but I will stick it on the dyno just to get a baseline hp/tq/a/f.

[William Bonsell]

A lot of guys seem to target that fuel pressure and I personally set timing at 14, but that being said, I also know 16 degrees timing seems to be frequently used as well. Would sure like someone to explain the downside, if any, to setting timing a bit higher than 14......or perhaps a brief explanation of what is happening at various timing settings, 12-14-16 degrees. :I have a pretty much bone stock, but strong, motor with a tuned AFM......

[HoneyBadger - BrianW]

I just installed a timing wheel and FP regulator. I did dyno tune my car and ended up at 14deg and 52 psi on the fuel pressure. If you are not going to dyno tune your car I would suggest setting the FP at 54, just to be safe. For me it didn't make much of a difference in power between 52 and 54 and there was some added safety margin at 54psi. I will say that these numbers are safe if everything else in your car is running properly. If you have some underlying fuel delivery issues then you could still be running lean and just not know it.

For what it's worth, I have the original engine my donor came with (130K miles) and I made 116hp/110tq with the 41mm plate and 110hp/107tq with the 37mm plate. Not exactly pro motor stuff there, but probably pretty strong for an essentially stock engine.

[Kyle Burkhardt]

Thanks guys. 14 and 54 it is.

[Kyle Burkhardt]

Um . . . . so, if one were looking for his FPR on his 99, where would one find it? Any tips for removal?

[HoneyBadger - BrianW]

You would find it on the bottom of the fuel pump assembly with a rubber hose attached. I purchased an adjustable regulator at dieselstorm.com, but there are many places you can get them from.

[Mike Collins]

Buy the one from Dave Wheeler. Great piece, installation takes less than 5 minutes. You will need a fuel pressure gauge to set it up.

[Caveman-kwebb99]

Been doing alittle research and need to confirm my understanding is correct. I have a 99. Right now, I'm not looking for that last 2hp so I'm not interested in dyno tuning. I'm looking for a standard setting for FP and timing that produced the most safe hp without tuning on the dyno. It looks like the FP set by the modified OE regulators for sale on the net (52-54) and 14 degrees should do the trick. Any other suggestions?

Oh, and I'm not running a A/F guage now (but will once I go AFPR and spend the coin on tuning), but I will stick it on the dyno just to get a baseline hp/tq/a/f.

If you want a set it and forget it FPR call Drago! Simple remove a part put his part in go racing! I think price is arounf 100 bucks or so! http://mazdaracers.c...ure-regulators/ HERE IS THE AD!

[Kyle Burkhardt]

As I'm thinking about it, I may just buy an adj FPR so down the road when I want to do some dyno tuning, I don't have to buy more parts.

Has anyone posted up a write up on doing the timing? I've seen the one on miata.net, but I need pics and non-broken english instructions.

[Johnny D]

I just installed a timing wheel and FP regulator. I did dyno tune my car and ended up at 14deg and 52 psi on the fuel pressure. If you are not going to dyno tune your car I would suggest setting the FP at 54, just to be safe. For me it didn't make much of a difference in power between 52 and 54 and there was some added safety margin at 54psi. I will say that these numbers are safe if everything else in your car is running properly. If you have some underlying fuel delivery issues then you could still be running lean and just not know it.

For what it's worth, I have the original engine my donor came with (130K miles) and I made 116hp/110tq with the 41mm plate and 110hp/107tq with the 37mm plate. Not exactly pro motor stuff there, but probably pretty strong for an essentially stock engine.

Was there a difference in PSI settings between 37mm and 41mm?
J~

[HoneyBadger - BrianW]

As I'm thinking about it, I may just buy an adj FPR so down the road when I want to do some dyno tuning, I don't have to buy more parts.

Has anyone posted up a write up on doing the timing? I've seen the one on miata.net, but I need pics and non-broken english instructions.

If you buy a timing wheel that has already been slotted it is a simple process. I even did it between sessions on a race weekend. You remove the main belt, remove the 4 bolts that hold the crank pulley on and swap your stock timing wheel with the slotted one. Depending on how the slotted wheel is setup you can just advance the wheel all the way to the end of the slots or you might need to adjust it with a timing light. Once you begin to remove things it will (or should) become obvious.

[HoneyBadger - BrianW]

Was there a difference in PSI settings between 37mm and 41mm?
J~

No, I used 52psi for both plates. There was some slight differences in the mid range(maybe .1 or .2), but the top end was basically identical. I will not be changing any fuel pressure between plates.

[Kyle Burkhardt]

No, I used 52psi for both plates. There was some slight differences in the mid range(maybe .1 or .2), but the top end was basically identical. I will not be changing any fuel pressure between plates.

Would you expect that if you ran without a plate (say in PTE trim), you would have to significantly increase psi? Anyone have a number?

[HoneyBadger - BrianW]

Would you expect that if you ran without a plate (say in PTE trim), you would have to significantly increase psi? Anyone have a number?

First let me say that there are many many people that would be better qualified to answer this than me. I did not dyno the car without a plate. Since you asked, though, I will make an educated guess. I would think that you would run leaner without a plate on due to the increased amount of air, lowering the percentage of fuel in the mixture. To properly answer this question I would need to know whether or not the car uses the O2 sensor at WOT to alter the duty cycle of the injectors. I don't think that it does, but a change that large in the amount of air allowed into the engine could definitely alter things.

If I was going to run without a plate and didn't have access to an air fuel gauge I would probably increase the pressure to around 56-58 or so, just to ensure I didn't burn holes in anything.