|
|
Register To Post |
| biggrizzly | Do I need an AFPR? | ||
|
2011 Memorial Day Car Show Winner!
 
|
I'm just curious if I need an adjustable Fuel Pressure Regulator or not.
I have been suggested for my setup to run 30# SVO injectors and a 58mm TB. Which I'm sure if probably overkill for my cam, but We'll see. Anyhow, Lloyd never told me if I needed an AFPR or not? If so, any recommendations on a moderately priced good unit? |
||
Posted on: 2008/2/29 1:20
|
|||
|
_________________
Don Haller Corvette Club of America 94Coupe, 383Stroka, PeteK Trans, 3000stall, 3.54rear, Konis and bigger sways. |
|||
 Transfer
|
 
|
||
| dan0617 | RE:Do I need an AFPR? | ||
|
Senior Guru
 
|
I think you do need one at this point. I have a Holley adjustable regulator that came on the fuel rails with the HSR intake and so far I don't like it. I hate the tiny little adjustment screw that you have to pull the vac line off to adjust. I'd rather have a big knob. More importantly, my car pulls 12 inches of vacuum at 850 rpm idle. I think that is decent vacuum, but it doesn't pull the fuel pressure down much. If I hold the throttle at about 1300 or so rpms it holds more vacuum and pulls the fuel pressure down more. I'm running a little rich at idle and I think it is because the regulator doesn't let the vacuum pull the pressure down far enough. Don't know how to fix it yet, luckily it isn't too bad. Smells rich and blinks a rich flag on and off while datalogging but no smoke out the exhaust and it will idle all day without loading up and dropping the rpms so maybe it isn't that big a deal.
|
||
Posted on: 2008/2/29 3:26
|
|||
|
_________________
´89 Vert, 383, 230/236 cam, AFR 195's, LT Headers, HSR intake, 2800 stall, Zex 200 shot, ET Street Radials, tune by me. Runs were with D36 3.07's. On spray, 10.55 @ 132.78, 1.55 60 ft. On motor, 12.08 @ 113.15, 1.66 60 ft. |
|||
|
Transfer
|
|
||
| CasetheCorvetteman | RE:Do I need an AFPR? | ||
|
Elite Guru
 
|
No, you DO NOT need an AFPR. Use the correct sized injectors for the job they are going to be doing and set the injector constant in the PCM, this is the right way to do the job. If you dont think 30 lb/hr is going to be big enough, use something bigger.
And you dont need a 58mm throttle body either, that is just a total waste of money. Instead of buggerizing around with the fuel pressure, do the job properly and reprogram your PCM for the 30 lb/hr injectors. Turning the pressure down will not fix the fact youve got the wrong sized injectors in there, and adjusting the fuel pressure is NOT the way to tune that either. All youre doing is confusing the sh*t out of the PCM cause its never going to flow the amount of fuel it thinks its flowing, itll always be more or less, and it will make it harder to tune it properly too. If youre changing the cam and the throttle body you WILL NEED to program the PCM anyway, so it makes no sense at all to put in 30 lb/hr injectors and leave the injector constant at 24.87 lb/hr. Dan, the reason yours is running rich mate is cause its NOT TUNED PROPERLY. The fuel pressure changes with the vacuum for a good reason, and its got nothing to do with engine speed. The lower the pressure in the manifold, the less resistance to the fuel to flow, so it requires less pressure to leave the injector. If youre vacuum isnt high at idle, you dont want the pressure to drop lower, cause there is more resistance for the fuel to leave the injectors. The pressure in the manifold WILL have an impact on the amount of fuel that flows while the injectors are open. Manifold absolute pressure is almost as important to fuel flow as fuel rail pressure. You simply dont lower the fuel pressure cause the engine isnt spinning as fast, it does not work like that. |
||
Posted on: 2008/2/29 7:08
|
|||
|
Transfer
|
|
||
| biggrizzly | RE:Do I need an AFPR? | ||
|
2011 Memorial Day Car Show Winner!
|
Case,
Thanks - I just got the PCM back. It has been tuned for the 30# injectors. The 58mm TB was the same price as the the 52, 58mm was recomended by the head & cam guy that has done tons of these packages. He said it won't hurt and I could grow into later if I choose. Thanks for clearing up some information for me. |
||
Posted on: 2008/2/29 11:59
|
|||
|
_________________
Don Haller Corvette Club of America 94Coupe, 383Stroka, PeteK Trans, 3000stall, 3.54rear, Konis and bigger sways. |
|||
|
Transfer
|
|
||
| CasetheCorvetteman | RE:Do I need an AFPR? | ||
|
Elite Guru
|
Well the fact of the matter is i dont think you could ever flow enough to exceed a 52mm body, so youll never grow into a 58mm i dont reckon. If you flowed that much air, 30 lb/hr injectors are not going to be nearly enough, and streetability wont be worth a damn, cause youll be lucky to get any of that!!
DONT waste your time with an AFPR though. Why bother? Youre not blowing in 22psi from a massive supercharger, so you dont need to up the pressure, and if the PCM is set right, you dont need to drop pressure either. I do have another question for ya too, why did you send youre PCM away for changes? You can do it yourself from any computer with a COMM port, you just need the software, and its quite cheap in my opinion.  |
||
Posted on: 2008/2/29 12:16
|
|||
|
Transfer
|
|
||
| dan0617 | RE:Do I need an AFPR? | ||
|
Senior Guru
|
I had my tune done by pcmforless. My BLM's during normal driving are always between 114 and 126. 128 at WOT, of course. In a couple of weeks a friend of mine is giving me a tool that plugs into the cig lighter, then has a wideband 02 that will go temporarily in my extra bung. It will check the air fuel ratio, then I will know what is up. I had him look at it last night and he said it is fine, any car with a bigger cam will smell a little different if you are standing behind it between the pipes because of the extra cam overlap. I have no idea if that is true or not and am going to wait to check the air fuel ratio before doing anything.
|
||
Posted on: 2008/2/29 13:06
|
|||
|
_________________
´89 Vert, 383, 230/236 cam, AFR 195's, LT Headers, HSR intake, 2800 stall, Zex 200 shot, ET Street Radials, tune by me. Runs were with D36 3.07's. On spray, 10.55 @ 132.78, 1.55 60 ft. On motor, 12.08 @ 113.15, 1.66 60 ft. |
|||
|
Transfer
|
|
||
| cuisinartvette | RE:Do I need an AFPR? | ||
|
Elite Guru
|
Time to learn to datalog, it will help a ton in getting the tune "right", not close . If you do decide you need an AFPR let me know I have a brand new Crane in the box Ill give you, Ill never use it.
|
||
Posted on: 2008/2/29 13:11
|
|||
|
Transfer
|
|
||
| biggrizzly | RE:Do I need an AFPR? | ||
|
2011 Memorial Day Car Show Winner!
|
Quote:
I do have another question for ya too, why did you send youre PCM away for changes? You can do it yourself from any computer with a COMM port, you just need the software, and its quite cheap in my opinion. Well the ADL cable is around $100, and the software is a bit more. I was going to do it myself, but got a lot of things going on at the same time and it was one more thing I didn't have to worry about at this time. It cost me $190 round trip to PCMforLess and I know that he has done good work before. I shipped it on Friday and had it back on Wednesday the same week. Perhaps later I'll choose to play with it, but I also have Tony's Corvette Shop right up the road to do a final Dyno Tune on it as well. Tony is in my Corvette Club and always treats us good. whether or not I'll ever flow enough to ever need the 58mm, I got it, and is irrelevent as far as I'm concerned. It was recomended by Lloyd for my setup so I went with the formula that he has proven success with. It's not an issue. Is it? Cost was the same. I definitely wasn't going to stick that old POS carbon encrusted, oil-ladden, clogged 48mm TB back on it. As I said before cost was not an issue because they cost the same. |
||
Posted on: 2008/2/29 13:28
|
|||
|
_________________
Don Haller Corvette Club of America 94Coupe, 383Stroka, PeteK Trans, 3000stall, 3.54rear, Konis and bigger sways. |
|||
|
Transfer
|
|
||
| SpectatorRacing | RE:Do I need an AFPR? | ||
|
Elite Guru
|
I'm with Case, don't bother.
I put one on my car a few years ago (similar to your build but a bit more aggressive) because I was troubleshooting a problem, but guess where I have it set? 43 psi. My head porter and Alvin both tuned for that pressure so that's where she runs the best. ALthough I did richen up the mixture to post lower dyno numbers once... |
||
Posted on: 2008/2/29 18:55
|
|||
|
_________________
aka Scaryfast |
|||
|
Transfer
|
|
||
| CasetheCorvetteman | RE:Do I need an AFPR? | ||
|
Elite Guru
|
Quote:
I had my tune done by pcmforless. My BLM's during normal driving are always between 114 and 126. 128 at WOT, of course. In a couple of weeks a friend of mine is giving me a tool that plugs into the cig lighter, then has a wideband 02 that will go temporarily in my extra bung. It will check the air fuel ratio, then I will know what is up. I had him look at it last night and he said it is fine, any car with a bigger cam will smell a little different if you are standing behind it between the pipes because of the extra cam overlap. I have no idea if that is true or not and am going to wait to check the air fuel ratio before doing anything. Firstly, i dont think your tune is right. Secondly, the car SHOULD NOT smell different cause youe got a bigger cam, that is rediculous. Mine doesnt, it smells exactly the same as it always did, and exactly the same as my bone stock 87. You wouldnt mail order a bride, so why mail order a tune. Quote: Well the ADL cable is around $100, and the software is a bit more. I was going to do it myself, but got a lot of things going on at the same time and it was one more thing I didn't have to worry about at this time. It cost me $190 round trip to PCMforLess and I know that he has done good work before. I shipped it on Friday and had it back on Wednesday the same week. Perhaps later I'll choose to play with it, but I also have Tony's Corvette Shop right up the road to do a final Dyno Tune on it as well. Tony is in my Corvette Club and always treats us good. The cable is nothing like that price, i dont know where youre looking, but that is an outrageous price. Its more like $40 tops. I made my own for under $10. The Tunercat software was $69, and the definition file for your car is $20. Since youre taking it to a dyno for a final tune, why would you bother with a mail order tune? What they wouldve probably done is sent you another tune they did for someone else with a simular setup, and in 2 previous experiences ive had with their tunes (from 2 different Corvette owners), they both had the VIN for a Chevy Camaro, 2G1FP22P5V2116899, and both were almost exactly the same tune for 2 different cars. |
||
Posted on: 2008/2/29 22:47
|
|||
|
Transfer
|
|
||
| biggrizzly | RE:Do I need an AFPR? | ||
|
2011 Memorial Day Car Show Winner!
|
Quote:
The cable is nothing like that price, i dont know where youre looking, but that is an outrageous price. Its more like $40 tops. I made my own for under $10. The Tunercat software was $69, and the definition file for your car is $20. Case, Your like Debbie Downer today Dude! I haven't seen you so cynical before! Even at your wonderful prices that you quote, it still isn't that much cheaper and my time is more valuable than that. Why did I get an initial tune? I'd like it to at least start-up and run ok before I have to drive it to the Dyno. Not even sure when I'll get it there at this point in time. Where did you get so much animosity toward PCMforLess? Bottom line - who cares if it gets the job done that I want? I haven't done anything wrong here! Good Lord  |
||
Posted on: 2008/2/29 23:28
|
|||
|
_________________
Don Haller Corvette Club of America 94Coupe, 383Stroka, PeteK Trans, 3000stall, 3.54rear, Konis and bigger sways. |
|||
|
Transfer
|
|
||
| Notorious | RE:Do I need an AFPR? | ||
|
Elite Guru
 
|
The AFPR won't hurt anything and can be a useful tool for fine-tuning. But it's not a cure-all for anything. I got one because my stocker was high-mileage. So since I was going to replace it, why not go with an AFPR? I have the Aeromotive and it's a fine piece and has been for many a mile now. That being said, I run it at stock pressure with 30# injectors in my 388.
|
||
Posted on: 2008/3/1 3:15
|
|||
|
_________________
I hate sporks... |
|||
|
Transfer
|
|
||
| CasetheCorvetteman | RE:Do I need an AFPR? | ||
|
Elite Guru
|
[quote]Case,
Your like Debbie Downer today Dude! I haven't seen you so cynical before! Even at your wonderful prices that you quote, it still isn't that much cheaper and my time is more valuable than that. Why did I get an initial tune? I'd like it to at least start-up and run ok before I have to drive it to the Dyno. Not even sure when I'll get it there at this point in time. Where did you get so much animosity toward PCMforLess? Bottom line - who cares if it gets the job done that I want? I haven't done anything wrong here! Good Lord :banghead] Youre taking what im saying the wrong way. #1 ive got nothing at all to gain by telling you what i reckon, and everything to lose by giving you a bum steer, and #2, youre the one that will lose money on things you dont need, which is what im trying to prevent. If youre saying you dont care, well thats ok, i wont spend my time trying to help. You shouldve just said that in the first place and i wouldnt have wasted my time giving an honest opinion. I have nothing against PCM4Less, just their work that i have seen is not something id be proud to put my name to, and ive seen alot of others that DO KNOW what they are talking about say the same thing. If it was me, id have spent the money on the software and the cable, made the required changes, run it with Datamaster (which gives you 20 free logs anyway) then using that info as well as a list of your mods id have enlisted the help of someone that takes abit of pride in what they do to tune it for you. |
||
Posted on: 2008/3/1 6:17
|
|||
|
Transfer
|
|
||
| biggrizzly | RE:Do I need an AFPR? | ||
|
2011 Memorial Day Car Show Winner!
|
Case,
Thanks for the explanation - No offense taken. I do understand what you are saying, and I still would like to get the cable and software sometime down the road, because I do want to learn how to test and tune my own car. It was just quicker and easier for me to have a reputable tuner get me in the ballpark on the initial tune. Cheers - |
||
Posted on: 2008/3/1 12:41
|
|||
|
_________________
Don Haller Corvette Club of America 94Coupe, 383Stroka, PeteK Trans, 3000stall, 3.54rear, Konis and bigger sways. |
|||
|
Transfer
|
|
||
You can view topic.
You cannot start a new topic.
You cannot reply to posts.
You cannot edit your posts.
You cannot delete your posts.
You cannot add new polls.
You cannot vote in polls.
You cannot attach files to posts.
You cannot post without approval.
|
|