Duane's 91 Z/28

iTrader: (1)

I have been spending quite a bit of time trying to find info and pics of non distributor small block Chevy engines with the crank trigger setup with little success. I know they require an LS type ECM (PCM) but I have no clue which ECM (PCM) to use. I'm sure my 7730 ECM won't work. I have seen the 4x trigger wheel sandwiched between the balancer and pulley and the 58x trigger wheel inside the timing cover. Which is better? I have seen several MSD and Holley one coil per plug setups with the distributor without the cap for timing only. Will any of this work with our third gen tpi stuff or with minirams? I know it makes drivability better and quicker response time like an LS engine. Any help would be greatly appreciated as I'm thinking of going this route sometime in the future.

RBob

iTrader: (1)

The early NorthStar DIS setup with the proper trigger wheel will work with the stock ECM. Be prepared to change some calibration parameters.

RBob.

Tuned Performance

iTrader: (92)

https://www.thirdgen.org/forums/dfi-...northstar.html

NoEmissions84TA

iTrader: (1)

Keep in mind that you still have to have the lower half of a distributor to drive the oil pump.

Duane's 91 Z/28

iTrader: (1)

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Hey thank for the link. I couldn’t find anything in my searches for this.

Tuned Performance

iTrader: (92)

A other good read

https://lukeskaff.com/projects/car/c...c-ecm-project/

Tibo

iTrader: (15)

Anesthis and I both have "distributor-less" ignitions. I covered how I did mine extensively (almost as a step-by-step how-to) in my build thread. MegaSquirt is what we used and I believe that we are both happy with our choices. The LS PCM while being more popular on this site is not as popular as the MegaSquirt route. Both have their advantages and disadvantages. It is not hard to do, the work is in the research and putting the system together to work properly.

Duane's 91 Z/28

iTrader: (1)

Hey Tibo, thanks for the info. Your car is awesome. I love it.

Tibo

iTrader: (15)

Thanks, I love it too. The MegaSquirt 3 forums have a ton of info on parts and part numbers for the swap.

anesthes

iTrader: (12)

Your stuff is way cleaner and better looking than mine though!

anesthes

iTrader: (12)

There is a million ways to do this. Most of the aftermarket management systems support nearly every trigger combination you can think of. I like MS and I've been using it since around 2009/2010. I'm using a 36 tooth trigger and NO cam sensor so I'm wasted spark.

I would advise you to get a oil pump drive for this purpose. I have the mallory one. I don't like the idea of modifying an old distributor, which I did do originally.

I welded the 36-1 to the back of my stock crank pulley, and the bracket bolts to the block near the fuel pump area. I'm using an EDIS ignition box. It's cool because it uses 2 wires to talk to the ECU, and it drives the coils directly.

-- Joe

Orr89RocZ

iTrader: (20)

Yeah many ways to do it.

Ls1 411 pcm with efi connection 24x ring sandwich between timing gear and balancer behind a vortec cover and their 1xcam distributors for oil pump drive and cam signal. I ran this with success until my ring keyway opened up. I didnt run a balancer crank bolt and my guess is the balancer worked forward some to allow ring to start shifting and throw timing off. Made for difficult starts but ran good once started lol.

If aftermarket ecm like holley you can run a variety of crank triggers bolted to the balancer. 60-2, 36-1, 4x msd, etc. holley has their own DIS system. I just like the 36-1 wheel since its thick and sturdy. Efi connection 1x cam signal distributor. Lsx coils. Works great as well. I run the 36-1 on my bbc and the holley smart coils

anesthes

iTrader: (12)

How do you like the holley smart coils?

The 1x cam dizzy takes two revolutions until it finds TDC, does that make for hard starts or does it start wasted spark/batch and switch to sequential ?

What makes a really nice cam sensor is the optispark.. It sends a signal identifying each cylinder, but obviously requires a lot of ECU processing.

-- Joe

Orr89RocZ

iTrader: (20)

Smart coils are awesome for boost guys. Waste for na guys or even mild boost guys

no issues with the 1x. Starts great. Just like an ls1 car. 36-1 crank has better resolution than the ls 24x. Cam sensor being 1x doesnt seem to matter. I’m not sure how the logic is programmed but believe it stays sequential and between the two sensors knows what cylinders are ready to fire

anesthes

iTrader: (12)

I guess in theory the crank is gonna trigger at 0 and 180, so if the cam pulses at the same time as one of the crank events it knows it's at TDC. So Maybe 1 revolution or less.

I know the real new OE stuff knows which cyl fired last on shutdown.. That's cool.

-- Joe

Bill Chase

Bringing this back from the dead. Hey Orr, is there any reason a guy couldn't use the stock vortec 4x reluctor and sensor with the Holley system? I know the black box vortec ecu had a hard ceiling of 6000 rpm, but nobody has said why, I have my suspicion it has to do with sensor resolution fading as rpm increases. But have yet to find anyone who has used the stock reluctor and sensor with Holley, most go 24x and use the stock vortec distributor. As you said there are many ways to go for cnp with the Holley system, I'm trying to do the obs cheap but not if it will haunt me down the road. Have read enough horror stories about the LS 24x and 58x losing sync at high rpm under heavy load once you start making serious power, seems it is a combination of reluctor runout and the Holley doesn't like it. At that point most end up going to a 12x,4x msd. And how would that apply to the gen1 that clearly isn't as refined?
I'd love to be able to use the stock l31 reluctor and sensor, and stock vortec dizzy for cam sync, but again there is zero info on the Holley forums, or here on anyone doing that.

Bill Chase

I mean, why not stay with the 4x signal if your ecu can handle it? Msd 4x flying magnet is the standard by which others have been judged for over 30 years, and even with the LS once power gets real many go back to the good ole msd 4x. What am I missing here, has 24x just became a fad for the sbc crowd? I understand it's benefits for a daily driver that spends 95% of it's life at idle to 3500 rpm. And when using a 411 ecu or newer it makes sense to use what the ecu wants
Guess I'd rather not spend 400-600 on a msd or Holley 36x with hall effect sensor if the stock parts will work with the Holley? If the only downside is slightly less resolution at low rpm I can live with that, I mean you step on the peddle, the trans downshifts and you're already at 3500 rpm when boost starts coming on hard right?

So why hasn't anyone used the l31 vortec parts with the Holley system? There is zero mention of it I'm Holley literature, I have read it front to back ten times. Searched for all the odd combos people have put together, and Nobody, I mean NOBODY, has used the stock reluctor and trigger for anything other than a 411 ecu, and most of them just go to a 24x setup to get cnp, maf, and tuning options available with that system, along with trans control.

anesthes

iTrader: (12)

A lot of guys are using 4x with MS and other aftermarket. Same as a dizzy. In fact, it's popular on the LT1 groups. I thought about it on my LT1 car but then you have to use a single roller timing chain.

They are not exactly using a vortec reluctor, but rather one machined especially for the LT1/SBC: https://www.eficonnection.com/home/p...shaft-reluctor

I can't remember exactly why you can't use the vortec on dimensionally, but $75 is cheap.

-- Joe

Bill Chase

I'm ok with a different sensor as long as it's something that would be readily available at auto parts stores and allows the stock cover and reluctor to be used. Heck, even if I had to grab a 24x reluctor from a 2004-2008 4.3 that would be ok if it fits the stock vortec cover. Will not be running enough valve spring on this to justify a double roller chain, besides if you look at what gm uses in the 602/604 crate engines and the rpm/abuse they take.. there is a lot to be said about using a quiet gm part that's available everywhere. I think the efi connection stuff is great, just would rather not spend that kind of money for one off parts that could leave me stranded if they fail. Not trying to be cheap as much as I am trying to do this with readily available parts, plus if they are an OEM design they are usually pretty damn tough. This thing will probably never see 6000 rpm, a distributor would work, but I definitely want the cnp and tuning options they allow. If msd used the same crank and cam sync sensor I could live with that and just carry a backup, but they are different. Thanks Joe

Bill Chase

The stock lt1 4x reluctor and sensor?

anesthes

iTrader: (12)

Yes, the stock reluctor is 4x, so two revolutions give you 8x, so it can be used in place of a distributor pickup.

You need to use the 96-97 timing cover for LT1 which has the casting for the crank trigger. Makes for a nice vortec-like factory finish.

Then the guys have two options:

1) Use the factory optispark as just a distributor, which will handle the firing order, or
2) Run a cam sensor in place of the optispark with to find TDC for coil packs.

-- Joe


-- Joe

Bill Chase

Upon further investigation it seems the 58x can be ran in untimed sequential mode in the event of a cam sensor failure with just a simple settings change on the Holley ECU. So I purchased the msd 85141 can sync, and efi connection 24x reluctor prior to knowing that. When it arrives I'll return it and pay for the 58x reluctor. Could've used the stock vortec distributor but with the blanking cap it is bulky, the msd is smaller. Picked up a pair of truck heat sync coil packs. Using the Holley black cast aluminum vortec cover and smp sensor. So the only electric part that isn't OEM will be the cam sync. Making a simple settings change and not having to carry a backup proprietary sensor =winning. 🤣

anesthes

iTrader: (12)

Using a normal GM cover and sensor, right?

What is "untimed sequential" ?

-- Joe

Bill Chase

yes vortec cover and standard motor products replacement crank sensor. untimed sequential mode still fires the injectors in sequence based on firing order, but has no way to identify the number 1 cylinder without the cam sync so it is untimed sequential operation. still better than batch fired, especially if using big injectors and trying to get a decent idle.

anesthes

iTrader: (12)

I'm not familiar with that term.

On some of the aftermarket stuff you can do alternating fire, and specify how many times to fire during a cycle.

I'm curious though, if you are individually firing each injector, but don't know what cylinder you are on, what's the benefit over firing the whole bank ?

-- Joe

Bill Chase

id imagine the biggest benefit would be not having all four injectors fire at once, and the unstable fuel pressure it could cause when trying to run larger injectors. so the benefits would still be better drivability, cold starts etc. once above 3000 rpm i doubt it would matter much. but in our application the benefit would be not sitting on the side of the road waiting for holley or efi connection to send you a cam sensor. you make a simple software change, fire the car up and keep rolling down the road. to change from sequential to batch fire would likely require fuel map tuning at idle, part throttle etc. think about it even untimed sequential your firing each injector 800 times per minute at idle vs each bank once or twice per rpm. it would be cleaner than batch fire no matter what.