Guest bastaad525 Posted July 5, 2003 Share Posted July 5, 2003 Was checking ebay for a good deal on an adjustable FPR..... okay the bosch one I'm pretty sure I could get that to work on the Z... man but the thing is ugly though.... I'm more wondering if the ford one would work...... $10!!!! Bosch FPR http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=42604&item=2421905543 Ford FPR http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33555&item=2421736354 $10!!! Or this one? http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=6763&item=2421053620 This one is a bit more.... still not bad at about $100, and that is with a pressure gauge already ready to go.... I know the auction specifies Honda Accord but he has other auctions up for the same regulator for different cars... I'd have to email them to find if it'd work on the Z I s'pose. I had another thread going about bumping up the fuel pressure, thanks guys now I know I dont really need to adjust it to run 10psi of boost, just asking about these FPR's as I figure I"m definately going to need one at some point in the future.... and...... $10 if that one will work I figure I'd better jump on it. Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted July 5, 2003 Share Posted July 5, 2003 The ten dollar one doesn't look like it would be the right thing for you. It's not setup with hose connections like the stocker. Not that it couldn't be adapted but, sounds to me like you have bigger things to work on for your swap. The bosch unit looks more like what you need. You could raise the fuel pressure the amount you need to run 12 to 14 psi when you have an intercooler. If your only going for ten psi and nothing more then the 100.00 one with the gauge looks good. In fact that one and the bosch unit look like they would be a good combination to use together. Use the one with the gauge to set your base FP and the bosch unit to set FP while under boost. Quote Link to comment Share on other sites More sharing options...
Guest jt240z Posted July 5, 2003 Share Posted July 5, 2003 If your patient, deals can be found all the time. I just bought an AEM 25-302R Adjustable FPR off ebay for $85(list $185). I won the bid for $66, but the reserve was not met. I asked the guy what he would take, and he came back with the $85 price. The unit was in his car for two days before he wrecked his new Eclipse. He's sending it to me in the original box. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted July 5, 2003 Share Posted July 5, 2003 The Bosch is a RRFPR = bandaid, not a real FPR. The Ford will not work, it needs a Ford fuel rail. Not sure I would trust the "Cosmo Racing" unit, butit may be a good unit. Look at Summitracing.com - they have a number of good units, like the MSD, or if you want one that can handle anything you can throw at it, get the Aeromotive or the AEM. Quote Link to comment Share on other sites More sharing options...
Guest z1 performance Posted July 5, 2003 Share Posted July 5, 2003 I would disagree a bit....the Bosch one is actually a capable unit, and is good for getting some extra adjustment out of your stock system. It is 1:1 still, which is what your stock one is. That means it adds 1 psi of fuel for every psi of boost it sees, but it is adjustable, meaning if you are running a pump that flows so much fuel its overtaxing your stock FPR (ie your pressure at idle is higher than stock), it could be adjsuted downwards. You could easily get hoses barb fittings for it from Home Depot, etc making it perfectly compatible with the stock fuel system. The second one I don't know anything about...similar to the first one in concept (not sure if it is boost referenced though). Third one looks basically the same as the first, but has a built in gauge (nice touch), With any of the units, regardless of manufacturer, it can only flow as much fuel as its smallest opening. The AEM, last time I checked, had a very small orifice to bypass unused fuel, so was not a good unit to use on cars with big pumps. The SX unit used to be like this too (I have one I can sell you if you want), but they may have changed it since I got mine 2 years ago (originally bought it to use in my GVR4, but ended up not using it due to the small opening. best unit we have ever used is the Aeromotive, which is what I use in my GVR4 now. This is where you start to see that the stock FPR is actually quite good. (Though not adjsutable, it has a nice big inlet and can bypass a very large amount of fuel (like you would get with a big pump). I run the Bosch Motorsports external fuel pump on my car, and am still on the stock FPR, with no plans to change it till the need arises. Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted July 5, 2003 Share Posted July 5, 2003 I agree that the Bosch unit is RRFPR but, it is set up to be adjustable in the form of 2:1 or more what ever you need. You would have to change out the diaphram in it every time you wanted to change you setting. I don't like that type when there are better units out there that can be adjusted without takein the FRR apart. Sleeper; I disagree while it's not exactly a perfect solution to increasing fuel to the motor under boost it is very cost effective and can be tuned to make good power. Obviously, you can't just slap this thing on and go to town with 20 psi or anything. It's good to about 13 psi give or take with a car that has all the other basic turbo upgrades. ie. intercooler, F. pump etc.. I ran one for several years and while my current setup is vasytly superiour in everyway it's also much more costly. You get what you pay for. Right? bastaad525; if your looking to increase your FP to run more boost I suggest the Cartech model of RRFPR. It is much more user friendly. Also I suggest that you get the car running and get used to 7 psi before upping the boost. Really it would make more sense to make sure the motor and all the wiring is sound before turning up the wick on the motor. Quote Link to comment Share on other sites More sharing options...
Guest z1 performance Posted July 5, 2003 Share Posted July 5, 2003 If the Bosch is a true 2:1 RRPR< then that is definately the one to get...no need for anymore of a fuel/boost ratio thatm 2:1...if you need more, its time for bigger injectors! The shims are super easy to do...I think the Cartech is similar is it not (but maybe can only be shimmed down to 3:1..I forget) Adam Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 5, 2003 Share Posted July 5, 2003 Thanks for the tips guys.... okay so no $10 unit for me... ah well, "you get what you pay for" is absolutely right Sleeper - Why exactly do you say an RRFPR is a 'bandaid'?? Most sources of info that I have on turbo Z's seem to prefer and recommend the RRFPR over a 'regular' unit, to raise fuel pressure under boost..... that sounds like it'd be a good idea to me. I know you said this is a bandaid for a crappy EFI system, which the Z does not have, but at the same time, when running higher and higher levels of boost doesn't it exceed what the stock EFI is capable of recognizing? That's why I figured the RRFPR was a good idea to compensate for what the computer was not programed for. I'd really like to hear the con side of this coin.... always looking to learn more about this stuff I wish the shop I go to for parts like this had the Sard FPR in stock still.... this was the unit I had in my ZX, it looked great, worked great, and wasn't too expensive, but they're on backorder til who knows when and no one else seems to carry them. Quote Link to comment Share on other sites More sharing options...
Guest z1 performance Posted July 5, 2003 Share Posted July 5, 2003 hmmm...we carry SARD (and just about every other JDM brand too!). A RRFPR is a bandaid..it is how far you take it that matters. If you want little extra headroom from your current injectors, then its a fine solution and works very well. But if you are using it to overcompensate for injectors that are inherently too small for their application, then its not a good thing at all Th SARD BTW is not a RRFPR...it is a fixed ratio 1:1 just like your stock one, but it is adjustable...we use it alot on WRX's when we use the big Denso pump (310 lph) and the larger 650 and 800cc injectors. Again, your stock FPR raises fuel pressure under boost (again, on a 1:1 basis). Its only fault is that it is not adjustable, which in my eyes, is not a fault at all. I would venture to say that in its present state of tune at 14 psi I am a solid mid-high 11 second car, and I am still using the stock one.... Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 6, 2003 Share Posted July 6, 2003 Kewl Z1 that's the car with SDS right? Or was it TEC I forget..... yeah I knew the Sard wasn't rising rate..... I'm getting so much info from both sides on this FPR/RRFPR issue..... but anyways again I'm going to be running so mild boost on this engine I really just want a way to get a little extra fuel w/o springing for an SDS or comparable, w/o having to spring for bigger injectors..... maybe it's a bandaid and wouldn't yield the highest performance to put an FPR on there, but if it provides the extra fuel that would keep my engine from being destroyed, and not cost the kind of $$$ an SDS or bigger injectors will cost, then I'm all for it. I figure one main reason I would want the RRFPR over an FPR.... is kinda the opposite of why most people would prefer... a regular FPR, if you increase the pressure over the whole curve to keep it from detonating under boost.... then you're probably running too rich off of boost, I would think? I dunno... I'll probably just hold out for this guy to get the Sard's back in... Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted July 6, 2003 Share Posted July 6, 2003 Sleeper - Why exactly do you say an RRFPR is a 'bandaid'?? Most sources of info that I have on turbo Z's seem to prefer and recommend the RRFPR over a 'regular' unit, to raise fuel pressure under boost..... that sounds like it'd be a good idea to me. I know you said this is a bandaid for a crappy EFI system, which the Z does not have, but at the same time, when running higher and higher levels of boost doesn't it exceed what the stock EFI is capable of recognizing? That's why I figured the RRFPR was a good idea to compensate for what the computer was not programed for. I'd really like to hear the con side of this coin.... always looking to learn more about this stuff. I've written extensive descriptions and explanations on why it's a band-aid. The RRFPR is tunable for a speed-density system, and much less so for a sensed-air system like the Nissan. I'll put it this way - if you need more fuel pressure than stock, your injectors are maxxed out for flow. Instead of band-aiding it with a RRFPR that will cause more problems, address the source of the problem -- get some bigger injectors and the means to tune them. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 6, 2003 Share Posted July 6, 2003 So do you not want any kind of adj. FPR at all? Lets say I do put the IC, bigger injectors, upgraded fuel pump and upgraded turbo, is an adj. FPR, rising rate or not, still not at all necesary or even helpful in any way? I wouldn't mind just X'ing it off my build up list completely and freeing up that $150-200! Quote Link to comment Share on other sites More sharing options...
Guest z1 performance Posted July 6, 2003 Share Posted July 6, 2003 OK, you seem to be getting a bit confused, so hopefully this will straighten it out for ya (yes, my car is the one with the TECII) The stock Nissan Turbo fuel pressure regulator is a non adjustable rising rate unit. That is what the vaccum source is for. For every pound of positive manifold pressure it sees (from he vacuum hose going from the intake manifold to the nipple on the regulator), it rasies fuel pressure by 1 psi. However, it is not adjustable. The adjustable ones are good for cars with monster fuel pumps, or for cars wher you want to run more baseline pressure than stock. Some aftermarket ones, like the Bell, Vortech, and others, are also rising rate and adjustable. What makes them significantly different from the standard one on your Nissan turbo is their ability to give an exponential rise on fuel pressure relative to boost, as opposed to the linear rise the stock Nissan FPR gives. Some of these are as high as 8 or 10:1, meaning that for every pound of boost they see, they add 8 or 10 extra psi of fuel pressure. So, on a ZX running 10 psi of boost, at their standard 8:1 setting, you would be adding 80 psi of fuel pressure at the full 10 psi of boost on TOP of your baseline fuel pressure of 40 psi at "0" boost (the stock ZX regulator is tuned to sit at around 32-34 psi at idle, then jumps up to 40-42 psi when you jump on the gas and boost is at "0". In other words, this is WAAYYYY to much extra fuel, as you would not only be freaking out your ecu, but also blowing injector seals, etc (not to mention the challenge in even finding a fuel pump that could support his kind of level)gualtor will provide under boost. I know on the Vortech, you can shim it down to about 2.5:1. The real purpose of these regulators is when turbocharging a car that was originally naturally aspirated. Since these cars typically have very small injectors, and were not conceived to ever see positive manifold pressure (aka boost), theur stock fuel pressure regulators typically run out of steam at aournd 45-50 psi, which does not make them very useful for turbocgharging. So by fitting a 2:1 or 3:1 adjustable rising rate regualtor (which gets installed in line with the stock regulator), you basically get the best of all worlds without a huge investment. At idle, the stock regulator is keeping fuel pressure at stock levels, whcih keeps the ecu happy in close loop mode. The stock regulator continues to be in control until boost is sensed..this is what the adjustment of the aftermarket regulator comes into play. Since it is being instaled inline with the stock regulator, you are using the adjustment screw on the aftermarket unit to set the point where it kicks in. I used this setup on my '99 2.5 RS, when we first turbocharged the stock motor. I used a 2:1 rising rate regulaotr by Magnetti Marelli, and I had is set to kick in at 43 psi. So at idle, pressure was at 36 psi, and when you first stabbed the gas it jumped to 42 psi of pressure, just as it does on a stock 2.5 RS. However, once you would reach 3 psi of boost, the Marelli unit took over and added 2 psi of fuel for every extra psi of boost it saw. So if I ran 10 psi of boost, at WOT and full boost, I ran a total of 57 psi of fuel pressure (42 base pressure, plus 3 psi of pressure the stock regualtor gave, plus 14 psi of pressure provided by the Marelli unit (7 ps of boost x 2 psi of fuel). As you ran more boost, fuel pressure increased as well. basically, the little 2:1 regulator allowed me run those kind of bosot numbers on the stock ecu and with the stock injectors. Assuming your car is a Turbo from the factory, and you are using stock Turbo injectors, with even a decent sized turbo and decent sized fuel pump and runnign sensible boost pressures, you will be fine with the stock regulator. This is especially true if you convert to an aftermarket ecu that eliminates the stock air flow meter and converts you to a MAP sensor, as the MAP sensor will allow you to control and extract much more from your standard injectors than the AFM ever could. As I said, I am running a huge cam, a pump that flows over 300 liters per hour, 480 injectors, a TEC (hence a MAP sensor), on a built motor with a T66 and I still use the stock regulator. At idle, despite the huge output of the sock pump, fuel pressure is exactly as it is on a stock ZX Turbo, teling me the orifice in the stock FPR is large enough to bypass the exta unused fuel. At WOT and full boost, fuel pressure remains at a constantlevel as well, telling my pump is not being overtaxed and regulator is able to keep pace with the boost pressure. Hope that helps! Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted July 6, 2003 Share Posted July 6, 2003 All fuel injected pressure regulators should be manifold referenced (the vacuum line.) RRFPR refers to the fact that the fuel pressure is not constant relative to maifold pressure. Hence, I call a FPR that rises pressure 1:1 with boost NOT RR, as it is simply referenced to manifold pressure. I use a normal adjustable FPR (the AEM, as it goes lower pressure than stock as well as higher.) But that is because I have a factory ECU with larger injectors. I introduced "unmetered air", so the ECU sees a smaller portion of the measured air than stock, so it will give the injectors less duty cycle. As I have larger injectors, this works out to the right fuel mixture - I will find out for sure when I dyno Saturday. I use the adjustable FPR to fine tune the un-metered air setup. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 6, 2003 Share Posted July 6, 2003 Z1 - okay dont get me wrong here I"m not posing this as an argument, just trying to understand how this would apply to the last ZX I had. My ZX had a built 2.9 high CR motor, but the EFI was 100% stock. When I first put that motor into the car, the EFI would not compensate for all the extra air the car was flowing and the higher compression, and the car would ping really badly at wot above 4500 revs. When I went to a dyno they said all I needed was an adjustable fpr, which promptly bought and installed, went back to the dyno. They increased the base idle fuel pressure to 42 psi, and this completely illiminated my ping, and got me quite a bit more torque at the wheels. Was this not the 'right' fix? They basically made it sound to me, like the old ZXs like mine had EFI computers that just weren't able to deal with increases in compression or for that matter boost, and that you had to 'trick' the ECU with stuff like an adj. fpr to get it to flow the fuel you need. I realize bigger injectors or a better fuel pump might have also done the trick, but at the time (heck... ALL the time) my budget dictated that I go with the least expensive option, which was the FPR, and which seemed to work wonderfully. With this turbo motor it will be the same way.... bigger injectors are out of reach, and I haven't looked into a fuel pump but I dont see them as beeing cheap, but if I want to get any more boost out of it, well, more than 10 lbs (after I get an IC of course) I'll need more fuel too, right? Will I not be able to use an adj. fpr in the same way I did on my high CR motor to get a little extra fuel out of it? Or will the stock computer still be able to compensate and keep the engine from running lean at say 12 psi? And yes you're right, I AM getting a bit confused but I'm trying to learn thank you for your guys patience and the great replies and information. Quote Link to comment Share on other sites More sharing options...
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