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Discussion Starter · #1 ·
I've just installed the JRSC on my 98 Type SH I've only had it idling because its still winter here and im not driving it, I've just heard different things about using things like the VAFC with it. Should i be using it or is it going to make that much difference. Any info or tips would be appreciated. Also is the Map controller from JR a good investment?
 

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As usual.....

He dude. Well as usual a really good question goes unanswered, while the same postwhoring about what exhaust or ignition system is answered 1000 times. So here's my opinion....

I am personally using a VAFC. I like it and its a great unit. You'll here most people say negative stuff about it and call it a band-aid. Well, maybe so. However, I don't know of anyone on this board who has actually posted showing damage or losses from using the VAFC. The real reason is that some people don't know how to tune with a VAFC. So that scares them. The Ultra Safeguards and Cartech FMU's are nice and thats what most people scream for. Rightfully so with the shitty 91 octane that most people have to settle for. Not to mention that some people aren't blessed with tuning shops with dynos or 1/8 or 1/4 mile tracks in which to test & tune at. I run 93 blended with 100 octane (50/50). Do I detonate? No. Do I run stock timing? YES. Do I have a high ass gas bill? Fuck'n A!
You'll be happy with a VAFC, baring you know what to do with it. The Jackson Racing V-Pac, MAP and BTM are great products that offer things that the VAFC doesnt. However, those some products look like they were made from parts at fucking Radio Shack and are WAY more $$$ than your VAFC. They are also not compatible with the VAFC. The map mod doesn't care for the VAFC toying with the inputs. Personally, I think that the Jackson Racing parts are great if you want to use someone elses recommendations. Its all in what YOU want. The VAFC gets big props from me. The Jackson Products are A-OK as long as you are ready to accept that those parts do not allow tunability on your part. Except for "VPAC's" adjustable engagement points which are redicoulously broad for what that kit can produce.

Good Luck!
 

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Discussion Starter · #3 ·
Thanks for you input, and yes your right on not having any shops to test and tune around here so its more difficult to get everything set up as good as possible. The jackson BTM came with the kit for my car and i just havent put it in yet or the fuel pump. the BTM shouldnt really affect the way the VAFC works though, should it?
 

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BTM & VAFC

No the BTM is compatible with the VAFC with no problem. The VAFC doesn't control any ignition timing. I can't stress enough to you about getting that Fuel Pump put in. I'd also like to recommend 2 products that I feel are VERY important.... #1 Air Fuel Ratio Guage, #2 EGT Guage (Exhaust Gas Temp) with the street/race exhaust probe. The boost is optional. I don't use a boost anymore since the VAFC reads the MAP sensor and displays +/- manifold pressure. Those Air Fuel and EGT go hand in hand. If your EGT raises erratically, then the Air Fuel can be checked for Lean conditions. The cool thing about the BTM is that you can correct it from in car! So those 2 gauges will really be of service for you more so than boost or other "show guages" as I call them.

Noticed you said you don't have a shop. Well do you have a track? If so you've got the best dyno in the world! The track is practical for tuning. I do almost 99% of my tuning at the track. If you have friends that are knowledgable about your set up or at least have basic skills, you can get the car dialed in pretty well by watching your 60 ft times, 1/2 track times and etc. If you do an adjustment and get slower in a certain length of the track, you can evaluate where you ar e losing power in the powerband. Its no so tough. I think you'll have alot of fun. Plus you'll look like Mr Bad Ass when your under the hood tuning in your JRSC Prelude at the local track. Have fun bro!!!

-J
 

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I'm not a big fan of using a MAP based fuel converter on our cars for forced induction fuel tuning.

These units will work on FI cars equipted with mass air flow sensor, becasue the mass air sensor can read the extra volume of air being ingested by the engine. For this reason, AFC units can stabilize a/f ratios to be almost flat throughout the RPM band.

All Hondas measure air intake based on manifold absolut pressure sensors. These sensors don't measure the quantity of ingested air, but rather the pressure and adjustemts are based on the ECM's programing. Because the JRSC is placed after the MAP, the sensor doesn't see positive manifold pressure. Instead, the MAP just sees a vacuum. Becasue faster moving air has less density, the MAP sensor gives an even more false reading to the ECM. To help solve this problem, the JR kit includes a relay system that tricks the ECM into increasing the injector's duty cycle. The JR MAP doohickie fixes the botched MAP signal and makes it more useable to the ECM for part throttle detonation problems.

The idea behind the AFC units is you can add X% of fuel at X RPM and have constant results every time. These units work by tricking the ECM air temp sensor into believing the opposite is true. As colder air is more dense with oxygen, more fuel is needed; to pull this off, the AFC will tell the ECM the intake temp is colder that reality and the ECM reacts by dumping more fuel. All youre ECM sees is you driving into a near zero ambiant temperature and dumps fuel in attemt to keep the engine at proper a/f ratios. The only problem with JRSC engines is the relay is already telling the ECM the intake air temp is near 30 degrees, which is almost the coldest setting on the fuel map. Tricking the air temps to look colder than this isn't really going to give you a wide range of tuning, at this point, as you're near the coldest setting to begin with.

I would rather spend the money on fuel pressure regulators, which are very reliable and have more control on the engine's fuel consumption. IMO, any AFC is a poor band-aid to solve fine fuel tuning needs on our engines.
 

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I use a V-AFC on my JRSC @ 8lbs, and a MSD 6A with the BTM. I have soooo much control over everything that matters, I have NO COMPLAINTS, I have been able to use a B&m FMU for vacuum and the JR for boost, and I only get a tiny bit of tip in on 80+ degree days. I also have a Walboro 317 and RC 370CC's. You will love the boost, I highly recomend going to 8-10 lbs however, it has no real adverse affects, and adds another 15-30 horse. Good luck!
 

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Discussion Starter · #7 ·
Thanks for all the info guys, i will take it all into consideration on my decision in what to do, i'll try the VAFC out for as long as i can, and if im experiencing problems i guess i may have to try a Cartech FMU or something along that line, i have the jackson FPR but thats only adjustable not a rising rate FPR. Thanks for all the help.
 

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SHLUDER said:
....i guess i may have to try a Cartech FMU or something along that line, i have the jackson FPR but thats only adjustable not a rising rate FPR. Thanks for all the help.
Well, the Jackson FMU that is in the kit is a nice regulator. Everyone screams "Cartech" but I've yet to be presented with exactly WHAT is so special about the unit or how it is "superior" to the Jackson one. If you are tying to add "finesse" to the set up I HIGHLY recommend the AEM FPR, it will replace the stock Honda regulator atop the fuel rail. It is a good tooling tool and is of great quality. I've had mine on for 6 months and had no problems.
I think that your VAFC decision will be rewarding. The comments made by gvtec, are all correct, and can not be debated. In my opinion, the unit needs to be used as a tuning tool that helps correct problems that you know are going to be there (ie; lean/rich conditions.) Reguardless of where the MAP reads from, a lean condition is a lean condition, fuel enrichment is the only cure! So if you look at the VAFC as a manually correction to the problem, you'll be fine. Do not think that the VAFC will tune every weakness in the car's powerband. It can't. But to call it a "band-aid" is bit harsh. I think the unit should be thought of as "daily medication". Reprogrammed ECU's and standalones are the only TRUE CURE! Though the true "piggy-back" units or the $$$$$ stand-alone's like Accel's DFI's and etc are really overkill. (Though if Apexi included some ignition timing control in the VAFC, it would be a MUCH better unit.) I think that the VAFC will be a great unit for your VTEC engagement, fuel enrichment, injector tuning and etc. Though right now with set up your running, its really all you need.
 

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titaniumgsr said:
Well, the Jackson FMU that is in the kit is a nice regulator. Everyone screams "Cartech" but I've yet to be presented with exactly WHAT is so special about the unit or how it is "superior" to the Jackson one.
What exactly make this unit so special. Lets start with...
  • Variable ratios-- The JR FMU is a 5:1 regulator, meaning it's going to jack fuel pressure 5lb for every 1lb of fuel pressure. This is pretty pig rich for 6lb engine, but safety is the intent. If you were to move onto 8lb on the JR FMU, this becomes a problem with way too much fuel pressure and over stressing the stock fuel system; take a look at the PSI rating on your fuel pressure hose and it will read "65 PSI MAX PRESSURE." Being able to vary pressure for higher boost kits is a bonusas well as lower ramp pressures for 310cc injectors.
  • Ramping fuel pressure-- The JR FMU doesn't do anything until 1lb of manifold pressure. This can cause the engine to feel like it bogs, if you slowly creep into boost. Becasue the JR supercharger can create instant boost, sometimes the lag in the FPR can cause the "tip-in" detonation. The Cartech allows for the fuel pressure ramping point to be sent up to 10" vacuum. This makes for a smoother transition in fuel pressure and solves those pesky tip problems.
  • Better construction-- The JR FPR is know to lock up. Some JR guys have to been known to go thru 2~3 units before they hit a "good" one. The Cartech units are not known to have such problems.

Not a bad product for under $250 that you can actually use.

titaniumgsr said:
If you are tying to add "finesse" to the set up I HIGHLY recommend the AEM FPR, it will replace the stock Honda regulator atop the fuel rail. It is a good tooling tool and is of great quality. I've had mine on for 6 months and had no problems.
The AEM FPR doesn't address any boosted fuel pressure. It'll just help in lowering static pressure for those 310cc injectors. Other than that, these units are known for weak diaphragms that will leak on boosted cars. It's good to see you haven't had any problems with yours... yet


titaniumgsr said:
But to call it a "band-aid" is bit harsh. I think the unit should be thought of as "daily medication". Reprogrammed ECU's and standalones are the only TRUE CURE! Though the true "piggy-back" units or the $$$$$ stand-alone's like Accel's DFI's and etc are really overkill.
I believe it's a poor tool for our engines becasue you make fuel adjustments based on one setting: wide-open throttle. Telling the AFC to dump more fuel at 3,000 RPM in normal daily driving is going to foul plugs and cause poor fuel economy. Becasue the AFC can't make adjustments on multiple TPS inputs, you've got yourself a $300 half-ass "tuning tool" for WOT. The Cartech can run circles around an AFC and leave $50 in your pocket to boot.

If you do the math, you'll actually find standalones are cheaper in the long run.

The average JRSC @ 8lb has/needs these products to handel timing, VTEC, and fuel control: MSD 6BTM/JR BTC ($250), Cartech 2005i or 2025 ($250), A'PEXi V-AFC, JR V-PAC, Field unit ($300), Walbro GSS-342 or other brand high-output fuel pump ($150). This comes to $950, without even addressing larger injectors or additional OE replacment FPR to more safely deliver more fuel pressure. If saftey is a factor, add another $380 for RC 310cc injectors and $50 for a B&M FPR for a grand total of $1380.00. Keep in mind these are raw numbers, but it's a reality number to judge with.

Take $1380 and tell me you can't find a good engine managment system. My total system cost on the EFI PMS with RC 440cc injectors was $875 for the EFI PMS, $60 for 3 BAR MAP, $175 for laptop tuning software, and $380 for RC 440cc injectors with clips. I spend $110 more than the average piggyback setup and can do substantially more percise tuning for boost and off-boost. I have fuel and timing tunability for N2O. I can datalog the engine's water temps versus manifold pressure and the list goes on and on.

Just some food for thought.
 

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All about the Benjamins.....

Gvtec said:
If you do the math, you'll actually find standalones are cheaper in the long run.

The average JRSC @ 8lb has/needs these products to handel timing, VTEC, and fuel control: MSD 6BTM/JR BTC ($250), Cartech 2005i or 2025 ($250), A'PEXi V-AFC, JR V-PAC, Field unit ($300), Walbro GSS-342 or other brand high-output fuel pump ($150). This comes to $950, without even addressing larger injectors or additional OE replacment FPR to more safely deliver more fuel pressure. If saftey is a factor, add another $380 for RC 310cc injectors and $50 for a B&M FPR for a grand total of $1380.00. Keep in mind these are raw numbers, but it's a reality number to judge with.

Take $1380 and tell me you can't find a good engine managment system. My total system cost on the EFI PMS with RC 440cc injectors was $875 for the EFI PMS, $60 for 3 BAR MAP, $175 for laptop tuning software, and $380 for RC 440cc injectors with clips. I spend $110 more than the average piggyback setup and can do substantially more percise tuning for boost and off-boost. I have fuel and timing tunability for N2O. I can datalog the engine's water temps versus manifold pressure and the list goes on and on.

Just some food for thought.
You forgot about the $900 - $1500 Laptop needed for those $175 laptop tuning software. Some of the fellows out here can't afford that. That EFI PMS is a NICE piece, but thats overkill for a 6psi Jackson Kit. The AEM FPR's diaphrams are a replacable item, and thats just to be considered "maintenance". Its a race part. Anyone thats using parts like that and think they never need maintence, is headed down a bad road. AEM suggest you replace it with your fuel filter, every 15K. Thanks for the info on the Cartech, glad to see someone is paying attention. The VAFC may be a 1/2 ass tuning tool, but for the budget racer, which 9 out of 10 seem to be, its a good piece. I can't argue TECH, I can only go with my personal experiences and share that. If anyone could afford the EFI, I's surely go for it!! But if $300 is all you got, its better than nothing. The Cartech sounds like a good investment but I can't see where it does everything a VAFC does. Though looking at what you wrote, it sounds like a good duel install. If you could afford it.
 

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The program isn't that resource demanding, needing a P90 and 32mb RAM. I run this on a '97 Toshiba that I found on Ebay for $250; I also use it for school, so it was written off as an "educational tax credit." You just have to konw how to play your cards right.

Standalone engine managment isn't for every budget. Considering we are putting $3,000 forced indution units on a sub- $20,000 that, which for most of us is our only car, it makes sence to protect your 5 year investment with the best possible techniques avaliable. To spend 7% of the total investment's cost to add longevity, safety, and power to the vehical's engine doesn't seem too extreem to me, considering one is going to spend a little over $100 more than the average bolt-on kit and achieve a better state of tune.

I was making referance to the items being used in +8lb applications, considering the higher tuned motors make about 230 whp. Factoring that at a conservative 13% drivetrain loss, that 8lb SC motor is making close to 53% more power over stock. That much of an increase in power needs good engine managment and that is the point of my arguement. I'm not asking you to get overly technical, but rather understand what the products do and what makes them operate.
 

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Gvtec: If you can, PLEASE hook me up with a number or website to get a Cartech for the cheapest NEW price possible. I know Jim Helbing used to sell them but I thought his number changed or something, and even then I'm pretty sure I no longer have it. I'm experiencing tip-in detonation pretty frequently now and it's annoying the hell outta me. This wasn't happening on my car until about a month ago, but now I'm ready for my car to start acting normal again.

Also, after I get the cartech, can I set the rise rate and tune the fuel pressure with it on my own, or would you recommend another dyno run? I really don't have the money for another dyno run or two, but I DO have an underhood B&M fuel pressure gauge if that will help me in tuning it myself. If you can, please give me some instructions on how to tune it myself since you've done it as well, and I trust your judgement.

OR, would you recommend the JR map controller?
OR, would you recommend Zips EBL+EFVC (EBL evo coming soon) for map control like the JR map controller + the features of the V-AFC, + boost control for roughly the same price as the JR map controller or the Cartech.

If you've read this far, you can tell that money is very tight with me right now, hence I can't really justify another dyno tune, nor can I even begin to imagine getting a stand-alone, but I do know that my car's tip-in problem HAS to stop!

Thank you oh great one!
 

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Jim has been in his new shop for a while, but I can't remember if this is a new number.

Motorvations Motorsports
(205) 661-3600

I put in the Cartech 20005i myself and was able to rough tune on the rich side with the aid of a B&M fuel pressure gauge, electronic fuel pressure gauge, and electronic air/fuel meter. I wish I could remember the fuel pressure settings I used, but they wouldn't apply to you anyways. I'm sure Jim could rattle off a good base setting.

This is how I went about messing with it:
  • Complete install and try to use Yellow Teflon tape, as it's more resistant to solvents than the white. The white will also work well, but doesn't last as long. Lifespan for the white stuff is 2~3 years, so it's no biggie. Since you already have the fuel hoses with the correct fittings, you are basically swapping out the JR unit; took me all of 15 minutes to mount and plumb the thing.
  • As the engine is running, remove the vacuum line to the Cartech. You'll then set the fuel pressure about 4lb~5lb more than what your current fuel pressure is. This sets the ratio to 4:1 ~5:1 (4lb of fuel pressure to 1lb of boost, for example). This is done by adjusting the screw on the end of the unit and where you will do the tuning. I basically made a few 3rd gear WOT pulls and watched the air/fuel meter and stopped messing with it when I was able to keep the lights in the upper 1/8th of the gauge. When I went to dyno tune with the Cartech with a wide-band, I found I was pretty close with my rough tune settings which were 12.3:1; a tad on the rich side, but better safe than sorry. I started a little on the lean side of 4:1 and worked up to about 4.5:1. If the upper RPM WOT run causes the a/f to fall out of "rich," use your head and get off the throttle. The pull over and raise the fuel pressure a tad. Repeat.
  • To adjust the bleeder screw, start with the screw in the fully out position. From there, work the screw inward until you find the fuel pressure ramping to you liking. You need to double check with Jim on the bleeder screw, as I'm uncertain which diretion to turn it.

To be honnest, I have never messed with a FPR before this one. I don't think a PHD is needed to install or tune one, but use common sence and don't make it harder than it has to be.

I got out of the piggyback business, just as the MAP came out. From the people that have it, they love it. I haven't herd anything negative about it. The only drawback is you can't change your injector's size. It seems to be a no headach item; install it and go.

I haven't seen anyone using Zip's products, but the few guys on the net. It sounds good in theory, but the application can vary. I knew a guy in college that was a EE and thought he was God's gift to circuits. He made several piggybacks for his car stereo amplifier and caused an explosion that took one of his fingers. No saying Zip's product will do this, but since I've been very careful of home made/low-level grass roots products.

If I were in your position, I would buy the JR MAP sensor. Not that I sponsor JR, but electronics tend to hold their value and integrity better than mechanical units. If you bought a Cartech and didn't like it/couldn't tune it, you'll find it's near impossible to sell a regulator once fuel is passed thru it; see how far USPS will deliver a package than smells like raw fuel, if you do try to mail it. See if you can find a used MAP off someone that has gone Hondata, as they will sell at rock bottom to break even.

Seek Jim's opinion, as he deals with this day end and day out and could point you to the best deal. Ask if he's got some used units...
 

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good information. While I've also heard good things about the JR map controller, I somehow don't think that it will solve all my problems. I think it might be good for me to start ramping somewhere in vacuum, simply because personal tests conducted by myself mostly today and some yesterday indicated that I may be having a problem there by really carefully monitoring the vac/boost gauge and a/f meter in combination. Perhaps it's the V-AFC's fault, and I'm not richening it up enough in lower RPMs, on narrow throttle, however I'm inclined more not to richen it too much in low rpms and narrow throttle for fear of a CEL, which would be a too rich/too lean code most likely and is easily resettable, but I hate that lil focker if it's not an emergency situation. Anyways, the V-AFC will most likely be gone soon when I do get Zips EBL simply because I want the ability to control the max psi manually from inside the car. Hence I'm thinking the cartech would be better for me than the JR map controller since the map controller won't adjust fuel pressures until 0 vacuum, where as the cartech will probably give me more tunability in the fuel pressure as well as the ramp rate to 10 vacuum. I think a cartech in combination with the EBL would be a fascinating combination, and am willing to try it that way. more feedback?
 

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Is it possible to add VAFC to a Type SH lude and keep the ATTS function? I am sorta confused on the electronics part to adding a supercharger. What do FMU, SFMU, EMS, and FPR stand for, and how do they differ from each other? I believe they all are units that electronically control the air/fuel ratio in the car right? Or do they control that and the timing as well? They are used with the stock ECU right? Or would I have to upgrade the ecu, to a hondate ecu? Could I update the ECU alone and have that control everything I need? Would any of these still work with the ATTS system?
 

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titaniumgsr said:
No the BTM is compatible with the VAFC with no problem. The VAFC doesn't control any ignition timing. I can't stress enough to you about getting that Fuel Pump put in. I'd also like to recommend 2 products that I feel are VERY important.... #1 Air Fuel Ratio Guage, #2 EGT Guage (Exhaust Gas Temp) with the street/race exhaust probe. The boost is optional. I don't use a boost anymore since the VAFC reads the MAP sensor and displays +/- manifold pressure. Those Air Fuel and EGT go hand in hand. If your EGT raises erratically, then the Air Fuel can be checked for Lean conditions. The cool thing about the BTM is that you can correct it from in car! So those 2 gauges will really be of service for you more so than boost or other "show guages" as I call them.

Noticed you said you don't have a shop. Well do you have a track? If so you've got the best dyno in the world! The track is practical for tuning. I do almost 99% of my tuning at the track. If you have friends that are knowledgable about your set up or at least have basic skills, you can get the car dialed in pretty well by watching your 60 ft times, 1/2 track times and etc. If you do an adjustment and get slower in a certain length of the track, you can evaluate where you ar e losing power in the powerband. Its no so tough. I think you'll have alot of fun. Plus you'll look like Mr Bad Ass when your under the hood tuning in your JRSC Prelude at the local track. Have fun bro!!!

-J

question for you:how much boost are you running? i see you use your vafc as a boost gauge. how much kpa are you reading if you are in full boost?at idle how much kpa?
 
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