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volkswagner

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About volkswagner

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    SAM!!!!!!!

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    WA
  • Cars
    510 wagon

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  1. You can absolutely make torque with any size exhaust. What I was getting at is that the normal NA rule of thumb of small exhaust more torque is not true for turbo motors. The power/torque no longer depends on exhaust scavenging which is why NA’s make more torque with the extra exhaust speed of a small pipe. On a turbo motor the pipe diameter really only matters for the manifold since the speed of the gas hitting the exhaust wheel is critical. After the turbo bigger is always better to prevent back pressure on the output of the turbo. Did Tristan ever put his car on the dyno with a larger exhaust or none? I think his torque would go up, not down.
  2. Unfortunately, with a snail in the way it doesn’t.
  3. It's hard to tell from pictures but It sits maybe 1" below the brake and clutch, which is pretty well placed for heel/toe. Then I didn't measure but sat and pushed the pedal with this in mind and it seemed to be 2-3" of throw *depending on where yo would measure it) before hitting the hard stop bolt. It feels right to me, not too short.
  4. Happy days driving the goon. A glimmer of excitement in a sea of monotony. Got some new JBC parts in so I replaced my hand drilled bare aluminum prototype. Bolt in adapter for B15 Sentra accel pedal assembly. Got an exciting shipment, haven't put them on yet. Parts in process, just a teaser photo. As mentioned, I've been struggling with fuel starving with tank levels as low as 1/2 full. No good, and with my track record I would rather head off the problem before it hurts the engine. After not being able to make it through the last AutoX I couldn't ignore the problem any more. Enter this surge tank. Not large but it's the biggest tank I could find that would fit in my planned location and not hang too low below the car. As well finding tanks designed for above mounting rather than bottom mounting (for in your trunk) was quite hard. 1L volume, can for size reference. Any sure tank setup requires a second pump. I was originally going keep the walbro, which is extremely loud and so I assume somewhat strained, as the high pressure pump. Then get a cheap low pressure pump for tank to surge transfer, but then I rethought. If I'm going through the trouble to add reliability, adding a cheap pump doesn't make sense. Then if I'm going to buy a pricey transfer pump, why not buy a pricey high pressure pump and demote the walbro to transfer duty. Bam, Bosch 044. About the size of a 12oz can, these get a much better job done than the Walbro. Test fit tank in situ. Just behind the rear floor board. The floor board will provide nice protection from road debris and this spot is also right next to the front leaf mount for bottoming out protection. Only hazard is a loose driveshaft 😅 A little more driving duty. Then I jumped on the conversion one weekend. Mind your step. A few brackets, a bunch of line re-routing, some head scratching. walbro picks fuel up from tank and pumps into surge tank, this then fills the surge until fuel exits through the top port and goes back to the tank return line. The oversized lower port feeds into the bosch pump which supplies the engine and the return from the fuel rail goes back into the surge tank as well. Thus even if the walbro starves out the bosch has to use all of the reserved 1L and it actually has to burn it since the return goes back to the surge. pre-filter relocated. not good spot for this... And a final car on the ground shot showing clearance. The results. Before: I was at 2/3 full when i starved out on full throttle and high speed cornering while autoXing Below 1/2 full I would starve out under a hard acceleration or prolonged full throttle. Below 1/4 full I would be able to hear the pump starve with just normal jostling from stop and go traffic and lights. Now: I drove well below 1/8 tank and was able to hear the transfer pump cut out but had completely normal AFR's under hard acceleration ad prolonged full throttle. Success! as long as one of the extra bajilion connections doesn't fail...
  5. The angle of the diff. is going to depend on the exact angle of the engine/transmission in the car. I've been using and app called "tremec tool box" it's made specifically for measuring driveline angles. You put it on you're engine and measure the angle with the phones built in instruments, then on the driveline, then on the diff. Then it tells you if you're angles are good as a system, super helpful. It looks for a max u joint angle of 3 degrees and a difference between front and back angles of less than 2 degrees.
  6. Ya, photos app is what I made this with. Movie maker was much better. Now it doesn’t even have clip transitions, lame.
  7. Uploaded some video from the last AutoX day. The mount was too shaky and the audio got reduced when it was uploaded, too frustrated to fix at this point. I'm mostly trying to figure out a good setup for the endurance car, it would be real nice to get good footage out from there. Anyone have a favorite free or nearly free video editing software that is beginner friendly? I know, probably a tall order.
  8. Not much new here. Wagon was out of commission for a couple weeks due to the starter issue returning. Current theory is that occasional back fires on cranking are reverse loading the bendix and damaging the one way bearing. Can't seem to figure out why i get the occasional backfire. My starting timing is 10 degrees retarded and timed right. I just put in a brand new one. We'll see how it holds up. Other than that, daily driving the turbo goon has been a pure joy. I was able to get my fueling dialed in quickly after the new fuel pump. So it was on to more fun fine tuning stuff. The car really seemed to stumble as the VVL switched on so I started by trying to get this better. First was to change my fueling maps to dual table switching. So far I had been on a single table, and this meant that when VVL switched, the ECU was still using surrounding table data from the low cams. This would cause a sudden dip in power before the cams came back on. With dual table, the ECU is able to immediately switch to a separate fueling table. With this method I was able to set the VVL and table switch to not switch on at all and tune purely low lobe. Then I could set the switch point WAY lower than needed and tune the other table for purely high lobe. Finally, using the VE as an approximation for power. It was as easy as cross referencing the two table to see at what RPM the low lobe power would drop lower than the high lobe power. I decided this looked to be at about 5800 rpm. Notice that the rpms cales are different. The low lobe starts to drop off after 5600rpm which makes perfect sense due to tribal knowledge of peak SR20 torque being at 5600rpm. Keep in mind that with no VVL, thats what you get and it just keeps going down. But switching to the high cams they just start coming on to full power at 5600, and away you go! This made the car much more smooth to drive. VVL would switch and there would be no stumble. BUT, there was still a noticeable transition. Almost like it would flat line for a while. The way I understand it is that if the system is tuned correctly the VVL transition should be imperceptible from a power stand point. if it drops power it was switched too early, if it has a sudden "kick" it was switched too late. Looking at the data, the problem was obvious. The VVL not only changes the lift of the cam but it also increases duration which causes increased valve overlap. This is great for an NA engine that can use that overlap to exhaust scavenge at the higher RPM. But on a boosted car, the sooner the exhaust valve closes, the sooner boost can be built up. to solve this the boost solenoid would need to slam the wastegate closed at the VVL transition to keep the same boost level. I spent a bunch of time trying to get the closed loop boost control to give me stable numbers and struggled. The issue was that in order to get the closed loop gains to respond quickly to the VVL, it would need to be very responsive which made it TOO responsive on the initial low RPM boost build up and it would overshoot. This is the best closed loop control I could get. You can see the boost duty on the solenoid going all over to try and maintain the target level. I even cheated the target boost levels on either side of the transition to get a bit of boost creep before the VVL drop. Meh. Eventually I ditched the closed loop and switched to open loop, I was able to quickly get a more preferred response. You can't even see the boost transition. I still have a little overshoot to tune out. You can't see it on these traces but the open loop has the added benefit of being able to keep the wastgate slammed shut at first to decrease boost lag. and also keep it wide open during low TPS cruising to prevent boost surges while in traffic and such. The solenoid duty table, really shows the response needed at VVL to maintain the boost level. Satisfied with this scheme now. I also made up an adapter bracket to bolt to the dome light holes and proved a 1/4-20 stud for standard camera mounting. AutoX tomorrow. Hopefully will get some fun footage from that.
  9. There is a youtube mini series that is currently airing that cover lucky dog. The footage is all from our first race. You know the one where we had no idea what we were doing and driving a time bomb L motor. Not much footage of us due to our brief drive time. 7:47 : You can really see the flapping hood issue we originally had!
  10. We're starting to think about the upcoming season. Work sessions will start soon. We'll start by just getting the necessary stuff accomplished but it's always fun to think ahead to what could get done. Current livery front runner.
  11. Yeah what they said. As a follow up, I haven't had any clutch engagement issues since I installed the auto-adjust one. Smooth and predictable every time. Much nicer to drive with.
  12. I don't remember exactly what I got it from. I went to the parts store with my old one and checked a few cars until I found one in stock. There was a switch over period where they all went to the auto-adjust version. Almost all of the bolt patterns and bores are the same on the cars. I wanna say I got mine for an S-chassis.
  13. It misses pretty consistently every few seconds at idle and cruise. May be that it does it all the time but isn’t noticeable at higher rev.s. I have a Taarks cam angle sensor , Hall effect. The odd thing is I have never once had a single trigger error from megasquirt and all my tooth logs look great. This makes me think the Trigger signal is good and it’s the actual ignition output that is having the issue.
  14. With the wagon finally reliably doing daily driver duty, it was time to put the pulsar in garage. My AFR readings have been even more odd seeming than usual, exspecially at idle and cruise. So I took out my O2 to do a "free air" calibration and see if that helped the readings look more reasonable. Thats when I noticed this large dent in the sensor housing... oh yeah, I sent 100K rpm turbo shrapnel past that sensor 😬 Needless to say failed calibration. While waiting for new O2 to arrive, I went looking else where for cause of my full duty injectors problem. Jeff suggested using the bluetooth borescope we have to record my fuel pressure gauge while driving. The idle pressure is set at 4bar ~60psi) which should climb to about 70psi with boost. Sure enough, the pressure would plummet to 30psi after about 4k rpm. Hence my injectors would stay open twice as lon to try and get the right fuel supply. Swappe pumps out and after adjusting the tables my max duty dropped to about 50% Much better! I had to investigate further. Turns out Walbro's have an unservicable, uninspectable integrated filter. This probably clogged real quick before i new I had dirty tank problems and installed a pre-filter. I would have assumed the junk would have pumped on through and damaged the gear teeth and causing lack of pressure. I didn't anticipate it clogging up and causing lack of flow. New O2 arrived. Didnt really solve any problems but certainly is giving me more reasonable numbers and is giving me confidence in my tune. A big remaining issue is a persistent ignition miss. I am thinking it is megasquirt build related at this point. I've changed plugs a few times chasing this and it's nice to see they are always an even color across ports which gives me confidence my intake isn't leaning a single cylinder.
  15. I forgot to mentioned the main motivation for the shock swap. Last autocross I could not at all keep my tires on the ground. Kept lifting up the inner and one wheel peeling on every corner. I attributed this to the rear shocks extension that maxes out and prevents droop. The Bilstein setup would only allow 0.75" droop! New setup puts it closer to 2.5", we'll see if this has the affect I hope for!
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