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JMortensen last won the day on October 18 2021

JMortensen had the most liked content!

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About JMortensen

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    Seattle area, WA

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  1. I agree with you guys and think it's the pushing back that makes the urethane ones sag in the middle, not any pushing down. Likewise I had a fiberglass airdam with a rubber piece about 3" tall on it, called a Flex-dam. Made in CA in the 70s and 80s. Anyway a friend of mine snapped a pic on the front straight at Buttonwillow, which is not that fast, and the rubber was flapping up and letting a good amount of air under the car. Replaced with plastic lawn edging to fix. Whatever you do, test to make sure it works after you've done it.
  2. Can't really see what you're doing on the bottom, but also blocking off the entire area between the front valance and the rad support helps to minimize air that goes through the grill and then down under the car. I expect you're aware of this already.
  3. I assembled the suspension without springs, used a ratchet strap around the A arm to compress, then I think I measured from the hub to the fender.
  4. Looks like Onesight1 and I are late to the party, but I think the main thing is that you want the suspension to have as much bump travel as possible and simultaneously want the rear tires to not hit the insides of the fenderwells. If you line the flares up with the bodyline like most do, then you will not have enough clearance for the tire, particularly if you have taller tires or run the car lower, or both. Taller tires and lower ride height seems to be the thing to do these days. Mounting the flares high enough to allow for the tire to move means installing the ZGs at a pretty awkward he
  5. Why do you have to pull the hubs? Bracket goes all the way around? Just cut out the bottom section and bolt it on.
  6. Oh wait. You meant a skirt at the front of the splitter. I had that idea about 10 years ago and emailed Simon McBeath and he wrote me back and said don't. Also emailed Glenn Bunch with the road race Challenger, because he had pics of his on the track with a splitter with a dam on it, he gave it a thumbs down. I shared all of that in page 2 of this thread.
  7. Yes, I did run a skirt. I have it set up on a pivot on the back and was going to run cables in the front, but as it turned out it didn't allow for much movement when installed and there was some other problem I can't quite remember so I ended up using AL fuel line smashed on the ends to make struts for it. Passes the "stand on it" test. 1/2" birch. 3/4 would be really heavy. I just went to Home Depot and found a flexible white plastic that I think is used behind showers or something like that to waterproof. Easy to trim to fit. Have a small 1/2" AL angle section on the splitter, and then it
  8. Guessing he found it when he was searching for "splitter." FWIW I ended up making one out of plywood. Didn't want to do it from CF and then break it immediately. Kinda glad I did. It has rubbed once or twice. I've been autocrossing with a club that has 3 classes: FWD, AWD, and RWD. Since the rules are wide open I've been thinking again about doing diffusers and all of that. Have a couple other projects going though, so nothing planned for the immediate future.
  9. You can weld the skin. Just drill out all the spot welds and remove the old roof, weld the new skin in its place. Another option is to cut through the pillars and weld back together. There are differences in the 240 and 280 chassis. Not sure what if anything is different about the pillars. Should be dimensionally the same as the hatches, doors (some lock issues but size and shape the same), quarter windows, and windshields swap. I have a friend who built his roll cage this way, cut the pillars, did the cage, welded the roof back on. A lot of people were poo-pooing this at the time, but
  10. There used to be a good variety of bubble flares that weren't bolt on. MSA had a couple different varieties IIRC, I had some from a company called MAS, Jim Cook Racing had some, there were others. You should NOT buy from this guy, has had a terrible reputation for decades, but he still has the pictures stolen directly out of MSA's old catalog showing some of the bubble flares: http://showcars-bodyparts.com/240z.html
  11. I think I figured out the turn part. You're just saying the MN is superior because it has the port at the same level and the valves lower. OK. Point taken, but again, you're starting with a head with smaller valves, so one might have a better port shape, the other has bigger ports and valves... ???
  12. I agree, it's good to keep hashing it out, although since switching to LS I don't care as much as I used to. It got pretty heated in those threads 20 years ago. I remember being particularly pissed off when Mack said something to the effect of "I can go half throttle and not have any pinging." LOL Here's a different angle: if it's not a race engine (at least a weekend warrior), then why bother bumping the compression up to the bleeding edge? If it is a race head, then why start with a head that has smaller valves and ports and liners when you could shave/shim and end up with something very
  13. I never bought the MN hype. Yeah, it has a small peanut chamber, but the ports and valves are smaller too and it has exhaust liners. If you really want that chamber, shaving a P90 seems to be in every way a better answer. I built an admittedly worse E31 that has less quench with about 11:1 and a bigger cam than most people run at .490/280, polished all the sharp edges in the chambers, etc. and needed 95 or 96 octane to prevent pinging. A bigger cam would have helped and I always tell people to go bigger when they start talking cams (stage 3 Schneider is not a good choice). Having been there
  14. No, sorry. Just convinced that the stock intake is restrictive and the stock turbo exhaust manifold has a T3 flange and is a crappy log manifold design.
  15. Turbo. An L at that power level will have a lifespan measured in hours. I've driven zredbaron's stroker with 300 bhp. It's a lot of fun. Also requires race gas and is fragile. By comparison, I have a 2L 4 cyl GTI with somewhere in the 280ish bhp range (based on the tune and mods) and I can drive it on pump gas, and I don't feel like it's in imminent danger of catastrophic failure. I would suggest if you turbo it that you ditch the entirety of the intake/exhaust systems and start over, new manifolds, bigger turbo, intercooler, tunable FI, get rid of flap door AFM, etc. If you were goi
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