Kirkster

We are happy with the tq numbers just want to push them a little higher in the rpm range before they fall off...

My SP manifold was a webbed manifold thus the alignment issues that hampered the SP non webbed manifolds was not there. The short runners killed the torque on the SP manifold. If I go turbo that manifold will go back on. It just does not perform well NA.

Yes it is the same motor/injectors/megasquirt with just the intake manifolds being changed along with the rebuild and overbore... Don't know what the cam timing is as the motor was previously factory stock and we did not check the cam timing when the rebuilt motorwent back into the car.

Yea, that stuff

More timing advance...

We are probably ordering an adjustable cam sprocket soon. Just putting a toe in the Hybridz waters on any other ideas...

I went to the webbed EGR intake due to the short runners on the Senza intake killing the torque on the motor. This advice was from a guy that was racing and crewing for them in the good old days Run file 12 is the Senza intake Run 44 is the webbed EGR intake. The longer runners definitely brought the torque back...

I am having the opposite problem. Oh and my tuner kept putting in more Advance and the engine kept liking it... I am thinking that I will be popping in an adjustable cam pulley soon...

Ok, Brief background. First Pull is from a few years ago with the group buy SENZA PARI intake. We figured the short intake runners killed the Torque on the motor. Second Pull is from this spring with a rebuilt .40 over motor as the old motor dropped compression on the #4 cylinder and had to be rebuilt. The motor is an N42 with N42 head and is completely stock with the exception of the .40 overbore. We are readying a new intake which will be port matched to the head and also will have had the runners opened up. The big issue we have with the current intake is this is a webbed EGR intake and the intake log is necked down for the last 2~3 cylinders and we are not sure if that is impacting the flow. So we are going to a non webbed non EGR intake that is the same diameter the whole way down the log. The real issue that we would like to solve is moving the HP and Torque a bit further along in the RPM range as the Torque peak is faith at 4400RPM and the HP peak is at 5000RPM. we expected it to not peak at such a low RPM. We are also thinking an adjustable Cam Pulley might help us move the peaks. Any thoughts??

Not sure that 158 hp was a lot. The MS3Pro was just the engine management. I did go to fuel injected and sequential injection/ignition with the MS3Pro and I would like to think that this would have some gains over a regular carb setup but I never dynoed the motor with any other setup. The intake may have helped a bit and I know the exhaust was less restrictive soooo... So to get the little bit of HP back we just kept giving it more timing and backed some out when we heard it start to detonate. At this point the motor was headed to rebuild so it only needed to last for another 30 minutes of running but I was not too concerned about blowing it up... (it made it through nationals and is now rebuilt and feels stronger than before, a dyno session is coming up and also E85 during the same session I hope) I will post up another dyno chart in a month or so after I get down to VA beach for some more tuning..

The injectors were only cleaned last week. The car was last at the dyno in April. The injectors were not flowing enough fuel in their clogged state in April on the dyno once the car was in the upper RPMs... So when clean high flowing injectors were installed it was flowing way too much fuel for the fuel map that was in there that tried to compensate for poorly flowing injectors...

The injectors and coil wiring fix just got done Saturday. So those were the first logs he had seen since it failed on dyno day...

And Fixed..... Turns out that once I had the injectors cleaned, and flow tested they were dumping way too much fuel. I sent the data logs to Peter and he said, "wow looks really rich now", He sent me a new fuel map and I drove it and Data logged it. Reved to 6K with no problem before it was running really rich. Sent him the data logs and he sent a another new fuel map and a new ignition map. Now it revs and pulls hard all the way to 7K. Now it will be off to see Peter in VA Beach for some Dyno fine tuning. Glad this ordeal is over (of course it is BSP so something else will break). Really stressing me out, and a great birthday gift!!!

Sent the logs to Peter, I let the log viewer update when I opened it today and now it's not working... Doh...

The Coil packs are genuine AC Delco D581s the plug leads are Magnacore 60285, not sure about the plug brand but the gapping was set at .035 when the plugs went into the car Not currently running a dwell table in the settings. the dwell is set to 3.0ms and the spark is set to 0.9ms. The crank and cam trigger wires are routed separately from the rest of the wires in the car as I was paranoid about EMI. The wires are shielded, and the MS3Pro has a shielded Cam and Crank wires in the factory harness which is what the shielded crank and cam wires that I put in are connected to. I will be taking the car over to the motor builder tomorrow to have him look things over. I will post up the dyno sheets when Peter sends them over to me.

Ok, The torque is not falling off, it is taking a 90° nose dive. I sent my tuner (Peter Florance) an email asking for the Dyno sheets from the last Dyno session as well as the first session with the car for a comparison. It is all on the same Dyno at Abacus Racing in VA Beach. I have a Wideband in the car and we did do a comparison between the exhaust tip ARF and the one in the car and they were within a couple % of one another so we in general use the one in the car when tuning. There was no trigger loss at high RPM. None in the counter on the TunerStudio gage cluster, and no cut out of the motor like last year. I know what this feels like since I had a crank sensor flake out last year and cause me all kinds of grief running it down. So this year I changed from the threaded sensor to the plastic body sensor with the mount tab on the end. it is able to have a larger gap than the threaded sensors and still work properly. My threaded sensor last year had a very tight gap and ended up being temperamental. Running 93 octane fuel (sunoco I think), the plugs were gapped properly when installed in the car, Since this is a low compression engine we don't think there is any detonation issues (we did not hear any and Peter does know what to look for) I can send you the log file from today if you want it. This was after I changed the fuel filter element for a clean one. (the old one was not particularly dirty but figured that it could not hurt to change it out)

Cam is stock. Fuel pressure never drops below 48 psi where it is set either. When I first started her up 2 years ago the filters clogged up and we would see the pressure drop on the Dyno. No drops when I was running it on the dyno in April.

So I got my rebuilt motor back in the car and have been having issues with it generating power above 5500 rpm. I am running a MS3 Pro with full sequential injection and ignition with GM D581 coil packs. For the first year or so it ran well with a mystery motor. 160WHP 150tq. Then that motor lost compression in cylinder 4. Which led me to a rebuild over the winter, I had planned on a Rebello motor but suddenly we became a one income family and plans changed. So I had it bored .040 over and dished .040 over pistons put in as well as having the head gone over and springs replaced. I dropped it back in and got things running and broken in and then took it to my tuner. He ran the motor in a bit more on the dyno before the first pulls and upon the first real pull the torque basically falls off a cliff at 5500 rpm. We did a few more pulls with the same results. My tuner then went through the tune to make sure everything was ok with the computer. We then did a valve job on the dyno and all the valves were tight, once they were adjusted we did a couple more pulls with the same result. So now I have had my injectors cleaned and flow checked and they needed it done and now the engine runs much smoother, I have also rewired the coil packs since I initially had them wired as LS1 coil packs where they needed to be wired as LS2, this led me to chop off the old connectors and put on some LS2 -rewireed pigtails which I was concerned could be contributing to the problem. Hence the rewire. So it ran well when I fired it up but when I took it for a spin it crapped out at 5500 rpm again. So now I am stumped. The only thing that changed outside the motor is that I am running a webbed NA intake out of a 280 instead of the group buy intake (which would be perfect if I could run a turbo). I am Also running a 65mm throttle body instead of the old 80mm. What could be causing the motor to fall off a cliff at 5500 rpm??? Not sure where to look next....

Sad news... He helped me a lot...

Already running a light flywheel and clutch. And a 3 pound li-po battery. Now I am trying to source motor rebuild parts.

I need to find some pistons. I am looking for dished pistons. The Nissan part number is 12010-Y4116 which was superseded by 12010-Y4133. The nissan dealers are telling me that they can't get them. What are my alternatives out there? ITM? Just checking to see... K

So plans have changed. Wife's Job gets eliminated Jan 1. The motor has been dropped off at a local shop for boring and honing... Still taking things .040 over and getting the head rebuilt and everything decked to the FSM max specs. Also have a webbed factory intake that I will be putting a 65mm 240SX type throttle body on the end of it and sealing up all the silly emissions holes in the intake. Only really need the brake booster, IAC, and MAP sensor connections. Will keep you all updated.

Tony, I actually got a good intake manifold from the group buy. It will probably be great for a turbo application but for NA it is less than optimal. I am currently looking at a factory FI webbed intake unless I can get something better. I have a webbed intake right now that I am going to have to do a bunch of welding on before I can use it. Just looking to see if there is anything else out there that would work better for a NA application. Not sure I am ready for ITBs though. I will probably be spending enough on a motor this winter, as well as Aero and other things for the car itself this winter.

Johnc, Any advice on an intake for fuel injection? Is the later model webbed intake going to do well or is there an obvious better choice for a Fuel Injected L28? K

I usually run the fuel tank at half tank and sometimes a bit lower. I have run into starvation at local events when I went to 1/4 tank. Already running no speakers. Have not felt like taking out the old push button radio yet (I kind of like the power antenna ) and you can't remove the OE wiring for the radio but the non OE wiring to the radio is gone. The radiator dry weight can't be less than the factory radiator so I have not bothered with that as I don't have any cooling issues. I know the seat belt retraction units are pretty heavy but I need to put in a harness bar before I get rid of those... I still have 2 horns... But most of the easy stuff is gone... The undercoating on this car is really thick so I could loose 20 pounds or more of that stuff... But the motor is my first priority now.