Those Who Have Used The Svo Extender...update!!!

Discussion in '1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-' started by RangerJoe, Aug 7, 2014.

  1. I am picking up an extender off of the corral. I intend to use this for the first few months after my HCI swap until I figure out the cash and tuning option. I can't find a full set of instructions for this thing, I have found the charts for the dials, but that's it. I read somewhere that it adds timing above 3000rpm, is this true? Anything I should know before the install?

    Thanks guys,
  2. Are you talking about the old SVO RPM Extender with the mixture knob on it?

  3. Just out of curiosity, how much did you pay?
  4. Yes
    85rkyboby likes this.
  5. That's the one!

    I need to get past the 6250 rev limiter for my 6500 rpm shift point. I figured a $100 wasn't bad if it holds me over a few months.

  6. I'm sorry but there isn't much experience with those boxes anymore. I never ran one, but I had at least 2 people I knew who used them in the late 90s to run EFI Renegade. Back then the only ecm mod you were allowed to run was that specific SVO box; you couldn't run a chip. It was kind of a weird rule. I really don't remember the specifics on how it affected the tune as far as timing.

    I'm finding it kind of hard to believe that you have to rev your car that high to get peak power out of it. Have you had it on the dyno yet to determine the peak power rpm? Your ET and mph is excellent for a stock iron head car, so I don't want to question your assessment of the shift point too much.

    If you are looking for a tune for your car, and don't want to drop the cash on a dyno tune, or can't find anyone qualified to do it, I can sympathize, because I'm in the same boat right now with the Cobra. There aren't too many people who are really experienced with OBD1 tuning anymore. I spent half a day on the phone yesterday, and either couldn't find anyone who knew what they were talking about, or wanted the car physically on the dyno. The art of tuning a car with a Pro-M MAF is almost gone. I was amazed at how many people said they didn't know how to work with a Pro-M/PMAS signal curve and insisted that we put a Lightning MAF with stock electronics in the car. The Lightning MAF just isn't a very good MAF. When I called Steeda in Lauderdale, they said they have to have someone drive 250 miles in from Orlando to tune on the rare occasion they had an OBD1 car in. I actually ended back up with the same tuner I used 15 years ago to tune my car. He was the only one still qualified to do it, and willing to mail me the chip without seeing the car. Bamatunes was the worst by far. They wanted me to start the car without a tune and tell them how it idled over the phone. I don't have time for that nonsense. 15 years ago I got a tune done by these guys and mailed to me. It runs flawlessly. I have had 2 stroker engines and driven almost 100,000 miles on one chip. Check out:

    They now use SCT hardware which is pretty much what everyone uses now. That means if you ever have the desire to get the car retuned on the dyno they can just adjust the chip you already have. $275 for the tune mailed to your door.

    85rkyboby likes this.
  7. On a side note, I remember that little SVO box costing over $400 in the late 90s. Now you can get a custom chip for under $300. Crazy.

  8. I had one before i bought the pms but never used it. There are instructions for it i hope you have them . It kicks on afr after 3k like you mentioned. I spoke to someone on stang tuning when i was gonna use it they said basically between fp and and the dial i could make it the commanded afr i wanted under boost.
  9. Hey Kurt, like I said in the original post, this is for use after my new HCI combo. Afr 185's, custom cam designed for 6500rpm shifts and systemax intake. A custom dyno tune is going to run $600 minimum, with future adjustments costing each time I go back. A used PMS (what I want to do) is $600 plus a few hundred for a dataloger.

    The extender is just to ride me over until I pull the funds and decide which way to go.

    Thanks for all the info guys.

  10. I'm running 192cc 17 degree heads on a 347 with a custom cam and I shift at 6200rpms currently. I really don't think the SVO box is going to bridge the gap for you. The problem with running a big cam and head setup is that the manifold pressure at idle is way too low. I suck 11 in at idle, the computer freaks out if it drops below about 14 in at idle. It freaks out, throws a CEL, pushes the IAC wide open yielding an 1800 rpk idleand dumps fuel in fouling up the plugs.

  11. It's stuff like this that makes me nervous about swapping to efi.
  12. You old school bastard. Carburation is foreign territory to me. All I've ever known is efi starting with an '87 crx.
    @revhead347 Once upon a time I had to break down and buy an obd I code reader because none of the autozone's etc had em behind the counter to let ya use. Now even the tuners are starting to not recognize obdI!? How are we gonna make it?
  14. Fast , BS3 , MegaSquirt , Anderson Pms . thank god
  15. Mail order tunes or obdII conversion?
  16. The Svo Extender gave me 3"
  17. those are your options as far as ECM :poo: goes befesides for a chip
  18. Ranger joe... The guy I use for tuning is in New Orleans. I know you are in Georgia. He started a forum site when eectuning site went down. this is the site.
    His name on the site is Decipha. Real nice guy and as far as I can tell he knows his foxbody tuning.
  19. Kurt, you may be right, we will see. Again, this is mainly for the rpm adjustments, so I can reach my 6500 rpm shift point. I value everyone's opinion and advice, but I have to say this:

    I am sometimes confused by the variations of advice a person receives on this forum. If someone wants to do a gt40 build, everyone wants to tell them to save for aluminum heads. If they want to build a high dollar stroker, they get told to swap in an Explorer motor with a tfs 1 cam. If they want an alphabet cam, they are told to go $400+ custom. I have heard numerous times on here about how the stock computer is very adaptable and tunes are not needed for most simple combos. In addition, I hear about how great fti custom cams idle and their great torque curve, that's why I spent the $400+ on it. This car will be tuned eventually, most likely by me with a PMS, but for now I just need the rev limiter changed and not melt the car down by having the afr too lean. I think the extender will cover that, I don't expect it to completely tune the car for max drivability or power, just keep it relatively safe.

    Sorry for the rant above, it just feels like everyone gives so much conflicting info sometimes, it's hard to know what to believe. Kurt, I am not saying I don't believe your experience, I know you have way more years in this game then I do. It's just when you try to buy the best parts based on careful planning, I hate to hear it's not going to work, LOL. I hope that having the properly sized heads, good custom cam, properly working sensors and EFI system, and pro-m meter will be enough to have a decent idle.

    BIG BREATH.....

    I have heard a lot of good things about him and read his posts on here and corral, he is a very likely choice if I have to seek professional help (that sounds funny doesn't it).

    FWIW, a corral member emailed me the instructions, if anyone needs them in the future.

    A5literMan likes this.
  20. RangerJoe, I totally understand. I completely sympathize with the advice given on this forum. I think far too many people have no problem spending other people's money. I wish I had more experience with that SVO extender. If it's worth anything to you, all of my friends ran 9 second quarter miles with just that box and no other ECM mods 15 years ago.