Originally Posted by CoolGuy094

AE85 - The OP does not have ANY means to tune his car in the fashion that you are suggesting. He said he is still on the stock ECU. He can't just go to a tuner and have them "tune" his car. He doesn't have a standalone ECU, GEMU, Flashpro, or anything of the sort. The ONLY tools he has at his disposal are the adjustable rising-rate fuel pressure regulator and the electronic signal modifier unit (MAP clamp) that came with the Comptech kit.

I agree with you that attempting to "tune" the AFR curve by solely using an adjustable fuel pressure regulator is a crude method. I think we (Junky, RAIN H8R, s2konroids, manic, and myself) would all agree with that. But with the OP's current setup, that is the best that he can do. He could take his car back to the dyno, have the tuner hook up a tailpipe sniffer and log AFR's, then adjust the RRFPR while on the dyno to make sure that the majority of his AFR curve is in an optimum range. I, personally, would call that "tuning". Perhaps this is just semantics at this point.

We were suggesting that OP purchase a $100-$200 wideband setup. By purchasing this setup, OP could actually skip the "tuning" session on the dyno if he wanted and just adjust the RRFPR on his own while monitoring how each adjustment changes his AFR readings on his gauge. I would imagine that the tuner would charge a similar amount for a few pulls on a dyno while adjusting the RRFPR. So why not spend that cash on a wideband setup that the OP can now use in the future to safely monitor his AFR and possibly make future adjustments to the RRFPR as needed due to climate change? OP needs to know his AFR's in order to properly dial in the equipment that he currently has equipped on his car.

OP is not going to go out and spend $1,000 on an AEM/Haltech standalone or slightly less on a GEMU (plus another couple hundred dollars on tuning charges) if all he needs to optimize his current setup is a simple wideband gauge system and a few of his own hours doing 3-4 street pulls.

Through the help and guidance of Junky, s2konroids, and old threads on s2ki concerning the matter, I was able to easily setup the RRFPR on my Comptech kit back when I was on 7 PSI using my wideband gauge and making a few street pulls with a buddy in the passenger seat. This setup netted me 290 HP on a Mustang dyno in the winter.

Originally Posted by AE85

Hi there. I think that would be potentially catastrophic advise. Just my opinion, but here is a couple of very real practical examples of why.

The AF sensor will be measuring the product of the fuel and air in all 4 cylinders (unless you are suggesting he buys 4 of these and have them installed in each runner which I dont get a sense of at $1-200). If he goes and buys the WB02, and then finds he is running lean (as some have suggested), he goes, ouch the guys say I need to put more fuel in (keep in mind there is already the presumption there may be an issue with his setup). He turns up the rising rate adjustable fuel pressure regulator and more fuel goes in, and his AFR's improve (according to his WB02 gauge). Phewl. BUT the issue was an injector in one cylinder was blocked and wasnt flowing sufficient fuel (or injector plug come off or wire broken or or or) and only one of the 4 cylinders was running lean. He now has what he thinks is a decent AFR and drives hard and enjoys life... till bore wash in the other 3 cylinders due to over fueling and detonation in one cylinder blows his engine up.

OR

If he goes and buys the WB02, and then finds he is running rich, he goes, ouch the guys say I need to pull more fuel out. He turns down the rising rate adjustable fuel pressure regulator and less fuel goes in, and his AFR's improve (according to his WB02 gauge). Phewl. BUT the issue was a spark plug had failed in one cylinder wasnt sparking (or a coil failed or wire broken or or or) and only one of the 4 cylinders was running rich. He now has what he thinks is a decent AFR and drives hard and enjoys life... till detonation in the other 3 cylinders due to under fueling and bore wash in one cylinder blows his engine up.

"Tuning" an engine with a RRAFPR and a cheap wideband at to gauge what adjustments you need to make when you have a decent chance you have an issue with your setup is seriously misguided and I get a few of you guys think its the way to go, but OP, dont take my word for it as Im a newb here, please test the scenarios I talked about above with a few tuning shops or tuners and get their opinion.

Originally Posted by herecomesboost

Originally Posted by MBHs2k

No one is suggesting the FPR is a great tuning solution. What many are saying is that if he wants to run the kit stock like he has it, he can crudely tune the car using the FPR. The only way of doing this is installing a wideband to measure the AFRs. Every tuner ever will tell you that this is not a suggested route and that there are many factors that the FPR cannot cover for. All we are saying is that people have successfully run the OEM ECU, wideband, and FPR with this kit for many many miles.

Originally Posted by CoolGuy094

In both of those cases, wouldn't the result be an obvious misfire? I've had one coil go bad, as well as one injector wire go out, and in both cases I had an obvious misfire. It was easily known that something wasn't right with the engine. Also in both cases, I would have NEVER been able to achieve any kind of constant AFR that would lead me to believe it was OK to romp on the car.

I stick to my suggestion. We could sit here and set up hypothetical situations all day and get nowhere.

Originally Posted by s2k manic

look guy you seem to know enough to be dangerous so lets brake it down the car runs a stock ecu and a map clamp that limits map sensor voltage to 2.93v. it has a rising rate fuel pressure regulator its a 5to1 so with a static fuel pressure of 58 psi at redline it will have 80-90 psi fuel pressure that makes up for lack of large injectors. the problem is the rrfpr has a piston inside that can stick and cause the car to run lean when that happens the stock ecu tries to stop the damage and it pulls timing which will cause a 50hp loss so will a clogged cat. egt isn't an issue if the afr is good its a supercharged car now with a turbo if you run too much boost and retard the timing to much you will blow fire out threw the turbo and burn valves even if your afr is good. look everyone that has commented has had a supercharged or turboed car for years and have road tuned there cars just stop