403 LS2 FD - LS7 Build for 2020!

[kinger]

Uffda - this is when I get annoyed with project cars. 

It has to be a flaw in holley don't you think?  it would be interesting to swap to a diff brand of ECU but holy heck that is way too much work so I see how you feel stranded.  The only thing I can think of is noise, I assume you have shielded wire going to both sensors and its chassis grounded at the ECU only right?  The LS is weird in that it doesn't appear to need shielding in some wiring harness but I am definitely going to run new shielded wires on mine.  Maybe my 6000 rpm break up on factory GM ECU I have is that I don't know.  I do know shielding them has zero consequence and so it will get done on my build

[digitalsolo]

Interesting on the Holley.  I had similar issues with my BS3 and my ProEFI on my old RX7.  Could never really sort it out and ran out of patience.  The only ECU that ever seemed happy a high RPM in that car was the OEM.   I don't know why aftermarket ECUs seem to have issues with triggers.   So far so good on Haltech for me, but man, this crap is frustrating.

[shainiac]

Not to cause scar, but have you checked the end play on the crank. I've had several friends with drag cars that developed crank signal loss. Several times it was from the torque converter pressure at high rpm pushing the crank reluctor forward and the sensor missing the teeth. Usually it ended in a worn thrust bearing, too. Should be less of an issue on a manual car, unless you have a gnarly pressure plate.

[MPbdy]

100%. I feel like Holley is just straight garbage at this point. If you read the forums and the Facebook page it’s just full of people with issues with the cam and crank sensors. Thought a more mature and simple platform like the Holley would be pretty robust, but nah. Often it sounds like it’s just improper wiring or grounds, which I know is not my problem.

The Holley harness uses shielded wire from the ECU to the sensors. The factory harness does not surprisingly.

I have no PWM or switching electronics in the car except for a single wire output creating a tach signal since the Holley’s native output is a V8 signal instead of a 4 cylinder signal and I didn’t want to remove my fragile dash to reprogram my speedhut tach.

I can disable that output and try again as I have RPM on my digital dash from Holley, but short of any RF generated electrical noise I already fully electrically isolated the PWM wire from any 12V that the Holley sees and it made no difference. As it is, it’s got a high impedance pull-up resistor so it’s not like the noise is getting back to the 12V bus. This is such a weak signal there’s no way it’s getting through shielded wiring and causing this issue it would be a longshot.

[MPbdy]

Not to cause scar, but have you checked the end play on the crank. I've had several friends with drag cars that developed crank signal loss. Several times it was from the torque converter pressure at high rpm pushing the crank reluctor forward and the sensor missing the teeth. Usually it ended in a worn thrust bearing, too. Should be less of an issue on a manual car, unless you have a gnarly pressure plate.

I’m positive we did when checking out the short block. It’s a factory assembled GM short block and the bottom end looked ok when we had it apart. Might be hard to do in the car now, but yes that is the only mechanical reasoning where this might be happening outside of an improper airgap.

Given that it’s exactly at 6800 rpm every time I feel it’s more electrical than a mechanical issue.

I’ll try the new sensor tomorrow and hope it’s the solution.

[cholmes]

My local tuner has been around a while and has tuned -- or tried to tune -- virtually all the "mass market" aka "hobbyist grade" aftermarket EFI systems and now flat out refuses to work on any fuel injected car that doesn't use an OEM ECU. The problem isn't the tuning, it's the weird failures. He ended up chasing tunes, trying to solve "tuning" problems that were really hardware issues. He also got tired of customers yelling at him after getting stranded with component failures that he had no control over.

Of course, the problem comes with wanting / needing capabilities that the OEM ECU can't provide. When the factory race teams run into that, it seems like a lot of them end up using Motec but man, you gotta pay big $$ to play with that.

I think the Holley and similar price point systems can work fine on a dedicated race car that virtually never sees the real world of street driving. I realize plenty of people use them on the street with mostly good results. My personal test for any control system -- or any part, period -- in a street car: would I be confident to just get in the car, gas it up, and drive it cross country like a stock mini van?

I sure hope you get it sorted MPbdy, it's a cool car.

[MPbdy]

Thanks dude! Yea, the robustness of an OEM ECU is nearly incomparable in the aftermarket. I know Exidous is going to tell me to swap to a MaxxECU haha.

Holley wouldn’t have a field full of cars at two dedicated LSFest events if the stuff was entirely shit, but man when you get bit it’s certainly painful.

I specifically ordered a sensor from a dealership because of reading horror stories of people having to buy 3 or 4 crank sensors before finding one that actually works. Rumors of ACDelco sensors shipped off Amazon that aren’t genuine etc. This type of cut and try BS is not up to snuff.

It seems at this point I could likely put a long runner intake on this thing and keep the limiter set to 6500 and be fine, but it’s gotta party haha. This is also a testbed for the solid roller motor that I’d want to spin to 8k. I sure am glad I’m not trying to diagnose these issues with that monster in the car.

[cholmes]

I think buying the sensor from the dealership is a smart move, and heck yeah, the first time you wind that sucker past 7k and it's pulling hard, it'll be awesome!

[FC3S Murray]

I agree man. OEM PCMs offer so much more resolution & refinement, howbeit that depth does come with increased complexity the more extreme the build is.

[Exidous]

Thanks dude! Yea, the robustness of an OEM ECU is nearly incomparable in the aftermarket. I know Exidous is going to tell me to swap to a MaxxECU haha.

I would NEVER do that but yes, you should do that. Only trigger issues I've had were with sensors crapping out. Lifetime warranty duralast gets old after swapping once or twice.

That being said, I get zero breakup ever with nasty shift cuts for the DCT. Glorious. 7200RPM all day. Tefzel shielded, mil spec connectors. My run is all the way to behind the rear bin. Crank, cam and knock are always a good idea to shield.

[MPbdy]

I guess I'll stop slandering the Holley stuff.  The new sensor took care of it!

https://www.youtube.com/shorts/P0mYTV7MlXc

7600 rpm baby!!

I did it a few times maybe just to verify 

Now I need to wrap my brain around wtf I need to do next hahaha I got a little derailed to say the least hahaha

[cholmes]

Glad to hear it! And a good warning to all the rest of us about where to buy sensors.

[FC3S Murray]

I disliked the video because you are convincing me to forgo my kid's Christmas gifts this year to buy an LS7.

[MPbdy]

Thanks Holmes!

I disliked the video because you are convincing me to forgo my kid's Christmas gifts this year to buy an LS7.

Damn hahaha. I got this complete engine w/ recently serviced heads for only $5500 before I dumped a little money into it    I've seen LS3's listed for more money. The powerplant is killer so far.  I think on break-in I probably need another 480 miles on the clutch and trans lmao.  The new ring and pinion are probably broken in by now.  I need to wrap the rest of the car up now so I can put some windshield time in.

Reflecting back on today, the engine did seem to run better and more consistent today.  I think the timing was moving around as the crankshaft was losing position.  I got on it a good 3-4 times today and it ran great each time.  One of them I rev matched down to 2nd and hooked it around a corner and rolled into 2nd gear and it drove into a light wheel spin.  It didn't blow the tires off so I thought it would hook up eventually, but as the RPM climbed it just kept hazing the tire until I lifted around 6000 lol.  I am so far really quite stoked on the power delivery with this short runner intake it is super fun.  Hazing 275 wide slicks in the midrange - not seeming short on torque lol.  I can't wait to start banging gears and driving it hard.

With the ignition problem resolved I was honestly a little stunned and didn't know what to do next lol.  NGL I lost quite a bit of time texting everyone I could think of hahaha. 

I futzed around a bunch with the I/O expansion module.  Took me a while to understand how to communicate with it in Holley's software.  The I/O's aren't the most intuitive in their software overall.  I spent quite a bit of time trying to plan these remaining wires and programming all my added I/O.

I ran a couple wires back to my trunk area for controlling my second fuel pump, and to try and wire into my fuel level sender as my Speedhut gauge has been stuck on full no matter what.  Well, the fuel pump wire works, but my fuel level sender still reads 100%.  I may be stuck pulling that surge tank back out of the gas tank to check the wiring, but I just put a full tank of gas in it unfortunately.

I also tried the AC again today and it seems to not be cycling on.  I'm hoping I don't have a leak.

And lastly, now that I could communicate with it via the I/O module, I see that my flex fuel sensor is not reading unless Chevron pumps E0 now which I know is not going to be true in California lol.

So I'm still in a bit of wiring hell, mixed with troubleshooting and learning the Holley, but it should be forward motion only from here on.


Also, this!  Way stoked about this beast of an oil cooler from Improved Racing.  It's a triple pass, and holds 2 quarts on its own not counting the lines.  They say it can support endless lapping in a 650+ hp corvette in the same orientation I want to install mine.  I've never had one on this car, and coincidentally I've also never had an oil temp gauge.  I got one of their thermostat adapters that mounts where the oil filter is.  I got the 212* thermostat since my cooler is so large lol.



Now that I moved my battery to the trunk I have all this space down low behind the radiator.  I'm going to mount it parallel to the ground with a small air dam - maybe a printed scoop or something to promote air to pass through it. 

[MPbdy]

Happy Thanksgiving!  Finally got some updates!!  Pretty stoked about them too.  Long and short of it, after thrashing on this thing completely rewiring it in a weekend, and finally resolving the cam/crank sensor issues, I realized I was kind of burnt out again lol. I also had an awesome birthday weekend planned by my wife last weekend for a big group of us to go climbing together in Joshua Tree.

I think I'm 4 days into working on this thing since the last post, but had a couple with slow progress.  Been up a couple times this week already though and it is turning out awesome.

The most exciting part is this oil cooler.  Everything fits exaclty like I had hoped.  My old man helped me get all this mounted up.  The brackets he made with just a torch, hammer, and a vice without a single square edge on it lol. First try on both brackets too.  It is super solidly mounted, and I ordered extra of these bitchin 8mm rubber isolators.  I squirted a coat of paint on the steel brackets today. We still have to weld up the piece of aluminum angle that is spanning the two sway bar mounts.  Lastly, need finish it off with a small scoop and build the lines and mount the thermostat adapter.  The lines are a dead straight shot under the engine stand I really can't wait to show off the final packaging.

This is Improved Racing's own cooler.  I have lines and fittings and heatshield on order now too that will be here Monday.  With this cooler I can actually get the car on a big track for once.

In other topics, my AC worked fine today, and I was able to resolve my wiring issues with the I/O's.  I dug through so much in the harness and in the software and really was getting bummed out again about some of my sensors not working, and then finally I realized.........I had the pins in the wrong holes of the connector lmao. I also was able to wire in another input for the AC, so now I can trigger my fans, and I can do an IAC kick for the AC if I need to.

So I've been able to check quite a bit off my list, with more to shortly follow with finishing the cooler install.  With the AC and fans working, I can final mount the ECU and tuck the harness inside the car and get the interior back together.  That I really cannot wait for because then I can finally take my family out in the car.