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Clifton

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Posts posted by Clifton

  1. At a 2.0:1 pressure ratio and using 20lbs/min, a 62-1 and E57 will be under the surge line were a 60-1 is a little above it.

     

    If you turn the boost down to say 10 psi will it go away? This only happens at lower rps right? Any chance you have video of it on the boost gauge. If I had my other turbo on I could go get a vid and see if it is what you are describing.

  2. I cant find any after market stuff though can you give me some links, aka forged pistons and rods, cams, oversized intake and exhaust valves. valve springs and retainers, etc i gonna do all the good stuff,

     

    The valves are pretty big to begin with, larger than VK45's. You don't really need rods (it's not a Chevy), just pistons if you want alot of boost. Cams aren't cheap. I would just do pistons unless you are after every last bit.

    Cams http://www.camshafts.co.nz/Nissan.aspx#VH41-45

     

    This guy made 446 rwhp with 6 psi, stock motor.

    http://forums.nicoclub.com/zerothread/296413

  3. Looking at a 60-1 map, assuming it's using about 20 lbs at 15 psi at 3000 rpm( probably less with 30% throttle), it would put you just in the surge range.

     

    I guess it depends on where you want the power and if max power is your goal. If you go smaller on the compressor side you can pick one out of the surge range and keep the fast spool. If you want max power and don't mind a little lag to get more then going bigger on the exhaust side. Changing a compressor wheel and getting a new compressor housing to match is expensive. Swapping the turbine and /or housing side is expensive too. Either can make the HP but the larger hotside would to it with less boost as it would have less back pressure.

     

    Looking back at one of your posts you mention this

    "When I was coming out of turn 7 ( a sever up hill right hand turn) it fluttered almost everytime I went through the turn."

    That's exactly what mine would do. Part throttle/ light boost through a long turn and you have to hold the peddle there regardless. If you do alot of track days I would go bigger on the hot side. I went a little bigger and it's not even noticeable on the track as long as the revs are above 3500. On the street you could drive around it.

  4. Your rpms can still increase as it's making power, the boost is fluctuating from the air stalling (surge). If you could do it at WOT in a taller gear you would get to a point were the engine could use the air and the surge would stop, if it didn't kill the turbo.

     

    I'm assuming it's a V or H trim is it's a T04B. If it's making that much boost at 30% TP with a V trim at that low of an rpm, it's compressor surge. The cheapest way to slow it down would be to go larger on the hotside a/r, like a .82. Going with a stage 5 wheel would work too but you would need to machine the turbine housing for it.

     

    I ran a full TO4B/ V trim compressor, O trim turbine (bigger than a stg 3) .69 a/r (alot bigger than a T3 .63) and could get it to surge at low rpms, part throttle.

  5.  

    Mine is 24" and I had to cut the core support to get the in/out through and the hoses barely touch the hood hinges.

     

    This would have half the pressure drop. I don't know if a lower pressure drop or longer tubes makes more power though.

     

    http://cgi.ebay.com/ebaymotors/TURBO-INTERCOOLER-22x6x3-Supra-7MGTE-1JZGTE-Mustang_W0QQitemZ270217548469QQcmdZViewItem?hash=item270217548469

  6. You should have set it on megatune. Check it though, should be 0% without touching it and 100% at wot. If your TP setting is set on megatune then it's right, but 30% throttle isn't much to make that kind of boost. If you open the throttle more the surge goes away and the boost needle stabilizes right?

  7. Guys,

     

    To start with I only get this under part throttle low boost above 3500 rpms.

     

    I thought it was WOT. Is it steady state part throttle, just cruising with no change it TPS?

  8. You didn't notice it before because your old BOV did what it was supposed to do and vented the surge.

     

    A BOV only vents on closed throttle. If the turbo isn't matched and it surges under load (WOT), no BOV will help that. Maybe you meant that but just wanted to clarify.

  9. If you only surge above 3500 but can make full boost below that, I don't know if it's surge. As the revs increase the airflow requirement does too and reduces the chance of surging. I would think it would be in the 2500-3000 rpms range with that turbo.

  10. I wouldn't pull timing after 4500, it's not helping. I would drop timing around peak torque and add it in after up to redline. It looks like most of the timing you pulled was off boost too and after 3400, I would start adding it after 3900.

     

    One way to rid it of surge would be to pull alot of timing at lower rpms were you are experiencing surge.

  11. Sadly, I don't have a voltmeter. I need to get one though because I've needed one a few times before.

     

    What should I check after I get one?

     

     

    HF usually has cheap DVM's for around $5. Cheap the voltage at the battery or straight off the alternator. Check it before you start it, when it's running and with the lights on. Even with all the acc on it shouldn't go below 12v. Rev it to 2k and check it also.

  12. It's turned into another one of those threads.

     

    Grassroots Motorsport mag did a tire test with 285's on a 18x8. Look up what they recommend for that tire, it's far from an 8". They chose that size and wheel because it works in the solo class they run in even though they can run a narrower tire they don't because it works. They did test one 245 and that brands 285 wouldn't mount it was so wide.

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