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Xnke

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Posts posted by Xnke

  1. Not unless you choose to run high RPMS....The stock caps seem to be just fine in big HP situations, but apparently the 8000+RPM motors SOMETIMES can break the main caps. I've only seen evidence of it twice, ever...

     

    Stock main caps with ARP main studs shouldn't give you trouble.

  2. Slushing the tank is kind of hit and miss nowadays...a LOT of the old standby, and some of the newer systems, of tanke slush don't hold up to the alcohols in fuels, and they turn to a sludge and/or loose adhesion and peel out of the inside. Make sure you get one rated for alcohol and gasoline!

     

    Not even the old "Red Cap" sealer holds up to alcohol mixed fuels, as it's designed for aircraft...which IIRC aren't allowed alcohol in the fuel!

  3. VW's are oil cooled, gents. Broken oil cooler line...no oil...

     

    Same with methanol injection. Just another thing to get hot and brittle and break, when you least expect it to.

     

    I see no point in adding complexity to a car just because.

  4. 3.1L should produce 300-320HP from a properly optimized head and cam, with a very good header, properly sized carbs, and a good tune. 100HP/L is a perfectly doable target for an aluminum-headed, 2-valve modified wedge combustion chamber. Cut 20% in driveline losses and you should look for 250RWHP to point out a good combination.

     

    Not that 250RWHP would be where I stopped looking for power, but it gives you an idea of where you are in the scheme.

  5. Seen it happen more than once, Tony. Also seen a Type 1 VW that was run out of coolant and overheated itself to destruction. Think about that one for a minute, then I'm sure you'll realize that filling the tank isn't the only reason that you could run out.

  6. You won't get the result you're after...It'll still knock when you run out of turbo-fluid.

     

    Just run a bigger cam profile and be done with it. No detonation problems, far cheaper, less hassle, and really, if you're running enough compression to need to retard the timing just because it's hot outside, you've built the wrong engine.

     

    I ran 9.7:1 on 87 octane for two years and two straight 100+ degree summers at 36* of timing advance with no detonation at all, on an N42 head shaved down to a 42cc chamber. With a stock cam, yes it'd knock even on 93 octane. With the mild cam that I ran, no detonation at all on 87 octane.

  7. You are probably very rich past 4k, which is close to peak torque for a 35mm runner diameter. once past the torque peak, fueling demands start falling and if the carbs are too rich you see power falling off.

     

    I stand by what I said, however. Spending Money on the bottom end is not going to help horsepower until you've spent the money in the head.

  8. It isn't really helpful, nor is there material to open the port that wide if you wanted to. Look at photos of professionally ported heads for your answers. What you take away from the photos is up to you, but there are a LOT of details that can be gleaned from a picture....and some very important ones that cant!

  9. If you cut 0.080" then you can swap for readily available longer valves and not have cam geometry problems.

     

    If you are only cutting 0.030" you don't need to worry about it, you will just take up the error in the lash pad thickness.

     

    There is a lot of half-information out there. if you are modifying the L engines, get the book and make the annotations where the book is incorrect...they're mentioned all through this forum section.

  10. Going to crib from the miata boys again...the car drives very nicely from 2krpm and up, but has the idle sag and stalls at lights if the idle is set lower. This is apparently caused by the very large throttled volume. Not sure hoe the Supercoupe got away with it, but one positive solution appears to be going back to the dual synchronised throttles, or back to the (imo dangerous) post supercharger throttle. I'll be setting up my old synchro setup again in the next few days and once that's done, tuning will take the priority.

  11. That narrow loading is a function of ITB's. That's why Alpha-N gets used for fueling with ITB's, because you normally don't get enough vaccum signal to have a clean running car at part throttle.

     

    Normally, you'd like to see at most 60kpA of vacuum at idle, with 35kpA being stockish...you say you see 80kpA or so minimum...this points to either a large cam profile with a late intake valve opening, or the classic profile of an ITB car...both of which can sometimes use Alpha-N better than speed-density fueling.

     

    You're doing ignition timing, so it doesn't make a LOT of difference for that here, being naturally aspirated.

  12. Also, R200LSD's are not so expensive...I just bought my OBX helical (much much nicer than the old ones) for 390$ delivered...Fit a solid spacer instead of those weak bellville springs and you've got the equal to a quaife.

  13. Both Precision kits I've used had the 1977-1978 weatherstrip...very thick...too thick for the earlier cars. I used the Mcmaster-carr weatherstripping after trying five different types locally and for the first time in three years, it's poured rain all day and all night last night and not a drop of water in the car.

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