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About Zcardude

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  1. Just took the car for a spin and it drives a lot better. Still not perfect but definitely having no problem spinning past 5000. I turned the boost down a bit to test with, but I am definitely able to rev over 6000RPM now thanks to switching my spark settings. I guess I should have started out in the megasquirt forum! The car still seems to sort of lay down a bit after 5000RPM but I am attributing that to the tune being way too fat (low 10s on my current tune) up there, and I can clean that up a bit with some more street tuning and then a dyno. If anyone is reading this and wondering what the heck I changed given my issues: I had a dwell type of fixed duty, with a dwell duty% of 50. Chickenman recommend that this was wrong and that MSD boxes like my Street Fire, actually can use a standard dwell, with a nominal dwell of 2 and a spark duration of 1.
  2. Ended up triple checking that piston 1 was at TDC and then not adjusting cam timing based on feedback from this thread. I just finished throwing everything back together and loaded up some different ignition settings on the megasquirt based on Chickenman's feedback. The car starts and runs fine but I have not driven it yet because it is late and I don't want to wake up the neighbors. This thing is bit loud I will report back with whether or not a simple tune change fixes the issue tomorrow!
  3. From the FSM, I believe it is retarded but I would love to be told that I'm wrong. My setup looks to be somewhere between these two: I was thinking that the notch on the sprocket should be to the right of the groove. Looking at my timing chain, I'm noticing any timing dots or shiny links. Possibly an aftermarket replacement chain? Here is what I see at the "1" position with the engine at TDC, same position that I took the previous pic of the cam timing mark at. Looks like there is some markings on the chain links, but they are on other links as well, notice the link before the "1" mark: I've never had it past 5k RPM. Ignition is controlled by the megasquirt, it is running an MSD street fire ignition box. I am getting pretty strong spark. New plugs/wires/cap/rotor
  4. Ok, it's late so I haven't gotten around to adjusting anything yet, but I set the engine at tdc and am thinking that the issue is not that the cam timing is off by a tooth, but due to a worn or stretched timing chain. The adjustment marks look like this: Looking at the haynes manual, I am thinking if I move the cam gear from position 1 to position 3 tomorrow, I should have the cam timing close to correct. I will try this out and report back unless someone recommends otherwise This is my first L-series and I have never had to adjust cam timing before, so some questions: Would this amount of mis-adjustment still cause my RPM wall near 5000RPM? Is it possible to be off by a tooth and have the timing this close to spec? It seems like this is an adjustment issue and not an issue with improper cam gear installation
  5. Thank you for your posts! I have not verified cam timing and I will do so before doing anything else. I guess I'm getting ahead of myself here. I'm really glad to hear of someone else having the same symptoms, I feel like this car is so close to being awesome just not quite there yet! I'll post back (hopefully with a resolution!) after verifying and adjusting cam timing
  6. I need some help doing a bit of troubleshooting determining if I am experiencing what I believe is valve float due to too much cam: I have an L28ET powered 240Z, running on MegaSquirt, with a t3/to4e turbo, lonewolf intake manifold, 2.25" downpipe to 3" exhaust, fmic, etc. After looking at receipts from the PO, I believe it has this cam: http://schneidercams.com/270-60F-14_LET6.aspx in a hydraulic P90A head converted to solid lifters, with new, stock valve springs. I believe the stock valve springs are very wrong for this cam. After lots of tinkering with wiring to the megasquirt, fixing grounds, new plugs, wires, cap, rotor, and some noise filtering in the megasquirt software, the car drives really well. I've been driving around for a few days, and cruising around, part throttle, and WOT. I start making positive pressure at 2000RPM, and get desired boost by 3500-4000RPM depending on gear and everything is dandy -- up to about 5000RPM @ 18psi, a little higher at wastegate, around 9ish psi, where it seems to hit a complete wall. When it hits this wall, it is able to maintain boost and holds stable AFRs (a little on the fat end - low 11s), but, I can hear what I think is the blow off valve going off a bit, and I am not really able to accelerate without shifting. It doesn't sound like it is having ignition break up or detonation, but it sounds sort of off. The Z is not very fast despite making a lot of cool noises What I believe is happening is that the cam is at the very limits of the lift that the stock valve springs are able to handle, and the valves are floating. Is that a reasonable thing to assume, or should I look elsewhere? The megasquirt was previously wired poorly, but I have it running so well now otherwise I am hesitant to blame it for the engine's current behavior. I am thinking that I should have no problem revving this engine to at least 6500RPM (7000 would be even better and a damn miracle) which would give me a reasonable power band - right now it isn't terribly exciting. I'm only in full boost for 1000RPM, then hitting a wall! Next, if that seems like a reasonable place to look, I was considering doing the Rebello outer valve springs and nothing else, as that seemed like the most cost effective way to get some better valve springs in place and test my theory: http://www.rebelloracing.com/nissan1.htm My questions are this: Is there any reason I should not do this? Is this enough valve spring to work well with my cam? Is there an even more cost effective solution? Should I hunt down a stock cam setup instead? Do you have any other suggestion for my performance issues? I'm trying to get this sorted out on the cheap, feeling like if I can't get this setup operating correctly, I am going to swap to a newer GM V8