Tim C

Backstory:

Back in 2001 or so we swapped a ramjet 350 crate engine into my brothers 92 RS Camaro in place of the stock 3.1. Fast forward to 2017 and he's bought a 15 Camaro and given the RS to my Dad (who paid for the crate engine and all back then when brother was in high school anyway). Dad isnt a car guy so he's found a 67 C10 with a blown 283. We're going to pull the RamJet out and swap it into the c10, but also install a LT4 hot cam cause Dad wants a little thump at idle.

Anyway realizing the Ramjet ecu's suck for tuning, I want to use the 7730 still in the 92 RS. Ive done a bit of tuning on TBI stuff but PFI is all new to me. From reading on this site and gearhead-efi I've just managed to confuse the hell out of myself, LOL

Now for my questions:

1. I assume there will be no problems using the original 3.1 memcal azty as long as I jumper the netres to put it in 8 cylinder mode. I plan to install a new 27sf512 on the memcal like I did on the 7427 Memcals from my TBI swapped F150.

2. Can I use a memcal from a 7427 in the 7730, assuming I change the prom and possibly jumper the netres? I can find them in the junkyard much more easily here. That will have the 5.7 knock board at least, or does this not work at all?

3. Can I swap the 7427 knock board to the 7730 memcal at least, or is it easier to just remove it and use an external board. I already have an external board from a TBI truck. If I remove the knock board from the memcal how do I jumper it? I haven't found clear instructions for that with all my googling.

4. Finally assuming all this is even possible, can someone point me to a decent starting BIN for the 7730 for the ramjet, which is basically a 99 Vortec 5.7 so I can have a solid foundation to begin tuning from?

ULTM8Z

I'm not sure about questions 1-3, but on 4, you could probably start with my Miniram Start Bin.

Short runner, log-style plenum... my guess is the Ramjet manifold won't behave terribly differently than a Miniram (at least to the point where it'd more efficient to start with a Miniram bin than a TPI bin... especially when dealing with the accleration enrichment stuff, which is literally like black magic for these types of manifolds).

Tim C

Thanks ULTM8Z. I assume the miniram start bin stuff is on your website linked in your signature? If so I will check that out tonight after work. That was my biggest worry, actually. Questions 1-3 were mostly seeking conformation that I had everything correct in my own head, LOL

ULTM8Z

I forget... if it isn't, PM me with your e-mail and I'll send to you.

RBob

iTrader: (1)

That will work. The limp mode calibration and knock filter won't be ideal, but it will work.

I'm not sure about doing this. I've never tried it or looked into the '7427 MEMCALs that much to know whether they will work or not in the '7730 ECM.

You can remove the filter from the '7427 MEMCAL and replace the one on the 3.1l MEMCAL. This I've done (and others) and it works.

RBob.

Tim C

Thanks RBob. I may try the 7427 Memcal I have extra. If it doesnt let any magic smoke out then worse case I may just have to cut a jumper and it'll still work in my TBI 7427. If it works then it's already got the 5.7 knock filter.

Also, If I use the knock filter from my 7427 MEMCAL, I assume I use a matching knock sensor itself? I.E. one from a 93 c1500 5.7?

RBob

iTrader: (1)

I'd stay with the stock knock sensor. Just check that it measures about 3.9K in resistance. The truck engines that use the '7427 PCM likely use the same as the '90 - '92 f-body 5.7l sensors.

RBob.

Tim C

Appreciate the help. I'll start gathering parts for the swap. We're waiting for the title to come back on the truck before we pick it up, so far just left a deposit to hold it. Not too worried because the seller is a state trooper, lol.

ULTM8Z I sent a PM with my email address.

ULTM8Z

Yep I just emailed it to you.

Tim C

Thanks again ULTM8Z. It's going to be a little while before I make use of the bin, I've still got to get the truck here and get the old 283 out of it and the ramjet out of the camaro, but I'll poke around tunerpro with the bin and get familiar with the new to me mask. Hopefully I can report back later this summer with good news.

Tim C

Just to follow back up in case anyone searches this out in the future, I put a new eeprom 27sf512 on a memcal from a 7427 TBI PCM with the jumper installed just like the v6 to v8 memcal mod. It seems to work. I havent been able to drive the truck yet because it still needs exhaust and non dry-rotted tires but I cranked it this weekend, set the timing, then let it run until the cooling fan cycled on and back off. The only code I got was 44- lean exhaust which makes sense because the sensor is about 1" from the open collector for now.

Unless something crazy happens on the test drive, you can use a 7427 memcal jumpered in a 7730, which is great because there are a ton of the 93-95 chevy trucks in the local junkyards, but no 7730 equipped cars. Plus the 7427 had a knock board for a 350.

Ultm8Z's miniram start bin seems to be the ticket too for a Ramjet manifold vortec head 350. It fires up great, idles great with the lt4 hot cam and revs smooth with no stumbling or popping so far. It seems like its going to be a great foundation to begin tuning from.

Thanks for your help guys, Ill try to update again once its on the road and tuned in over the next few weeks.

ULTM8Z

Great news! I've actually gotten very little feedback on these Miniram start bins... glad to know it's doing some good!

Don't forget you need to tailor the injector flow rate, the injector PW vs battery compensation tables for your particular injectors.

Tim C

That was my next step, I brought my nice fuel pressure gauge home from work this weekend and it's got a steady 45 psi with fuel pump relay jumpered engine off, the ramjet is supposed to have 24 #/hr injectors from the lt1 pn 17124248. I'll make those calculations this week while I wait for summit to ship the exhaust pipe to me.

I went through and selected all the manual trans options I could find and I set up all the setup stuff like base timing and fuel cut off. I adjusted the vss pulses to hopefully read my vss, which ill have to test when I can drive it I also played around with the fan on/off settings too get them where I wanted it for the initial start up. Now that Im armed with the acutal fuel psi i can make those changes and I'll be ready to stick my wideband on it in the extra o2 bung I added and go play.

LB87FORMULA

iTrader: (3)

The past couple years I've been trying to tune my vortec 350 with a ramjet 350 manifold with an EBL. I was able to tune it ok with a ZZ4 cam, but having trouble tuning with a lunati 20080130 cam, which is almost identical to the LT4 Hot Cam.
My main issues are rough and surging idle, fair power and throttle response. I am checking my knock sensor and module right now since I never get any knocks when tuning.
I am hoping to improving the tuning this week and wondering if this bin can be used to manually update my VE tables.

Tim C

Ive been driving and datalogging for a week now. The miniram start bin was a great start off point for me. It was a bit rich, blms were in the 108 to 115 range initially. It took two 30 minute drives to get it up into the 117-128 range. Ive done 8 30 minute trips so far. Blms are much better now. Im going to drive it again today to see if the latest bin will get me where im happy. I do see some knock counts but nothing bad, pretty happy with the start bins spark table so far.

It has run pretty good even from initial start up, the only issue I've got is a rich (on the wb o2 gauge) stumble and black smoke about 30 seconds after a cold start, with an occasional stall then too. If it stalls i have to hold the throttle down to re start so its definitely flooding. And a little surge or miss at light throttle cruising through my neighborhood after a cold start. Once it hits closed loop its running great. Once I get the ve tables where im happy I plan on working on this open loop stumble, I always mess with warmup tuning last.

ULTM8Z

I suspect the Miniram bin will help out significantly. I do notice that you have Bosch-III's in your signature. Make sure you have the correct voltage offsets for the injectors you're running (otherwise you could be doing a lot of tail chasing trying to get everything dialed in).

LB87FORMULA

iTrader: (3)

Today I replaced the power steering pump since the shaft actually broke the last time I drove it. This was a rebuilt pump that lasted only a couple hundred miles since I just changed to a serpentine setup when I put in the lunatic cam. The original pump lasted 30 years.
Since the car has sat for awhile, I recalibrated my WB. It idled 11-12 Fuel to Air, so time to do some tuning. I am a little surprised since I did some tuning and it should be closer.
Recently I had my Bosch III injectors cleaned and flow tested at Southbay. They gave me a voltage offset vs vbat table, which I updated in my bin. Didn't make much a difference since my voltage is constant and VE tables have been changed significantly from the stock bin.
However, I would be interested in the miniram bin to see how the idle VE area is setup and the overall shape of the tuning.
Since I am not that experienced in tuning, I would be interested in the how to improve throttle response. The car is signifcantly more powerful, but doesn't seem to have the torque and horsepower of a ramjet 350 with vortec heads.
Thanks for your responses. Looks like I need to do some more tuning runs.

ULTM8Z

The Accelerator Enrichment has a TREMENDOUS amount of influence on the driveability of the car (especially with short runner Miniram-type manifolds).

Even though a car may put down some serious power at WOT at 6500 rpm, it can drive like crap around town and "feel slow" and disappointing.

The AE is where I hope the Miniram bin will help people the most. It is almost black magic trying to get it just right and I've iterated on it for a long time. Ultimately, the LT1/LT4 values are what I got very close to. When you tune the AE, you have to keep one eye on the WB gauge... bogging doesn't automatically mean it's lean... you can easily get to the point where it's too rich (believe me, I know).

As far as your injectors, it's not a matter of your voltage being constant or fluctuating. It's a matter of the ECM being able to know how your injectors flow at a given voltage.

Tim C

Alright, I drove this thing Sunday afternoon and the VE tables seem to be decent. I burned another chip using the info from my datalog and the second test drive just seems to be bouncing the blms slightly rich or slightly lean on each test drive when changine using the datalog data, so I figure I'm basically done with the driving around datalogging part. The vast majority of the BLM data was 125-131 skewed more to the rich side. On the edges of the table I saw one or two cells a number higher or lower than that, but my experience from TBI tuning tells my OCD perfectionist self that more driving and dataloggins is only going to burn more gas with no real results.

After its in closed loop this thing runs great and it screams in this old truck. There are no issues with bogs or sags with throttle changes no matter if its a slight blip or if you floor it from any speed. It seems to pull off really good when you slip the clutch to get it rolling from a stop too.

The only issue now is on a cold engine (anywhere from 70* air conditioned shop to 95* ambient outside temp) start. If I crank it and let it idle for 4-5 minutes without touching the throttle it will idle fine then pull off fine and run great. If I crank it up and immediately start to back down the driveway after 15-20 seconds, while giving it some throttle while controlling the truck speed by slipping the clutch (just enough time to get out of the bay door fully) the rpm will drop like its going to stall. If you let off the throttle it will die ususally, if you kind of feather the throttle it will pop and spit and blow black smoke out and the wideband goes rich (10:1 pegged out). If you keep it from stalling it will idle again but you have to slowly close the throttle to do so. If it stalls I have to hold the throttle wide open to get it to crank easier. Even if I dont try to move the truck, just touching the gas pedal say to rev it will cause this black smoke and stalling issue until it has run for a minute or two, then its fine. Warm restart are fine too.

I noticed on the AE TPS-Coolant Factor for pulse width calculation table it seems to drop off around the temps I'm seeing the issues. 46*F it shows 0.938, 68*F its 0.602, 90*F its 0.391 Would tweeking this table be the place where I need to play? This TPI AE stuff seems much more complicated to me than the TBI stuff I'm used to.

ULTM8Z

I'd start by leaning out the open loop vs coolant. In fact I'll post my table values of you want... I leaned mine out since I posted the miniram bin since some other changes resulted in the open loop table being too rich with similar behavior to what you're describing.

Tim C

Post the tables if you dont mind. Ill compare it to what im working with and see if it helps.

Thanks again.

ULTM8Z

Here are my values for the open loop vs coolant

91.00
73.40
15.60
15.60
7.80
7.80
7.80
7.00
7.00
7.00
5.00
5.00
5.00
5.00
5.00
5.00
5.00

Fast355

iTrader: (2)

I ran into a cold start issue on a cammed Vortec TPI setup. I found that the ECM would not command timing advance until the engine hit around 100-120°F. Part of the warmup emissions stuff. I changed the parameter to enable timing advance all the way down to -40°F.

Fast355

iTrader: (2)

I ran into a cold start issue on a cammed Vortec TPI setup. I found that the ECM would not command timing advance until the engine hit around 100-120°F. Part of the warmup emissions stuff. I changed the parameter to enable timing advance all the way down to -40°F.

Tim C

I thought I'd bump this back up with a follow up and one more small question.

First, I didn't get an email notification for some reason so I didnt see you had responded Fast355. At any rate the updated table data Ultm8z posted made a huge difference in the cold start up on this truck just plugging his numbers in. Since I noticed the entire VE table was basically rich comparing his original base miniram tune to what I wound up with while datalogging, I went ahead and lowered the open loop vs coolant temp table another 10% across the board and actually 15% in the 46 to 90 deg F range of the table. This thing is running really great now. Throttle response is perfect to me, plugs are burning clean, wideband shows happy. It cranks right up and runs great from a cold start or on a warm restart say if I drive it to work and it sits from 12:30 til 5:45 or even if you just stop long enough to run in a store for 15 minutes. When you come out it fires right up and runs great.

The only issue now is if I crank it cold (sitting for more than 24 hours, not cold temp. Its 90+ deg here during the day, 75+ at night) and just move it out of the shop for instance so I can use the lift it runs like it used to on restart. For example I backed the truck out of the shop Friday night so I could change the oil and rotate the tires on my Mom's car in that bay. It ran maybe 30 seconds to a minute tops. It sat for an hour then after the oil change was backed out, when I fired the truck up to pull it back in it was stumbling, popping out the exhaust, and black smoke again til it ran for a minute and cleared out. It doesnt do this if you let it warm up more, just if you shut down cold and restart, is there a table to adjust fuel on restarts with $8d like there is on my tbi $0d ecm? I looked all over tunerpro and couldnt find one. It seems to me like its flooding on a cold restart since the intake and cylinder walls are still wet from the previous cold start. I can drive 5 minutes down the street to a gas station and it will refire just fine.

EDIT: It cranks fine on the restart, and idles fine too. The second you touch the gas to slip the clutch and get the truck rolling is when the spitting and black smoke starts up.

ULTM8Z

The Miniram start bin delivers quite a bit of AE fueling (which was the main point of creating it in the first place... mimick what GM did with the LT1/LT4 right off the bat and spare people the headaches of trying to go trial-and-error with it).

But, with an open loop that's too rich, you can get stumbling and borderline flooding if you trigger AE fueling while in open loop.

As with the VE, PE, and a few other parameters I can't predict about people's enging combo's... open loop is where the user has to do some tailoring to his vehicle.

When you start up the car (any time), it'll start in open loop. Recommend going in to the Open loop AFR vs coolant and start pulling out some fuel a little at a time.

Go to my website and pull down the Open Loop tuning tool. You can start playing around with the table values to see what it does to the commanded AFR.

http://ultm8z.com/DIY%20Tuning.htm

I emphasize "commanded" because what you plug in may not be what you actually get. You'll need a WB to see the actual AFR. For example, at idle (where I run open loop al the time) I command 14.13 to get an actual 13.2-13.5.

But, without a WB, you can make relative changes... i.e., if you think you need to raise the AFR by 1 point, you can see how a big change you'll need to make in the tables to get that much delta. Then simply see how the car reacts. If it behaves the way you like it, then it's not so important to know what the actual AFR is (unless you're ****-retentive like me! )

Tim C

Well I have a final follow up. I lowered the AE-TPS coolant factor for pulse width factor table pretty significantly below 133*F basically its flat from 25*F to over 200*f now. That seems to have fixed my weird rich stumble on restarts. I noticed the throttle response seems to be much better also on a cold engine, and it doesnt seem to hesitate after getting back on the gas after a shift (three on the tree in this truck). Wideband seems to show a very quick 11.5x:1 to 12.0x:1 spike when free reving in neutral cold now instead of 9.xx:1 or lower like it did before. I lowered the open loop % vs coolant temp table originally trying to fix this issue and it actually caused it to lean out so much it began surging at idle (16 and 17:1 afrs) on the cold engine but didnt ever completely do away with the rich stumble at tip in, although it did help so Im now easing the table back richer to get the open loop afrs a bit richer. Once it hits closed loop the idle surge seems to go away (its running closed loop idle, seems to be ok so far)

All in all this thing is now running pretty great, at least until cold weather gets here, lol. We got it running in late spring, so the truck hasnt seen temps below 70 degrees until it hit the mid 60s at night just the last week or so. Of course I see ULTM8Z has put out another new miniram start bin, with new updates, so now that I've got this thing about ready to put the cover back on the ecm, my tinkering nature is wanting to try it out

ULTM8Z

Hmmm...I'd be interested to see where your calibration ended up compared to the start bin and maybe some tunerpro data as well.

Also, what are your engine specs?

Tim C

Its a ramjet 350 crate engine so its basically a 9.4:1, iron vortec headed 99 chevy truck engine with 1.6 rockers and the ramjet manifold. I swapped the ramjet cam out for an lt4 hot cam but otherwise its straight like it was bought from the chevy dealer.

The initial miniram bin was pretty rich all over for me. Lower rpm cells had blms of 108 higher rpms were in the 120 to 124 range. After tuning and datalogging I scaled the ve tables back quite a bit especially lower in the rpm range, upper ve tables are a little leaner than the miniram startup bin, but not as much as the lower table is. It only took about 8 drives to get the ve tables close where i was happy with blms mostly in the 124 to 133 range with a majority especially in the most heavily logged cells in the 126 to 131 range. Further tuning drives were just swapping numbers back and forth above and below 128.

Im not knocking your startup bin at all, it was close enough that it definitely saved me weeks and weeks of aggravation, LOL. I prefer to start on the rich side tuning anyway because its much safer in my opinion. I imagine some of my issues stem from the fact that this engine is in a 67 c10 pickup with a 3 speed, and not a much lighter camaro. I know vehicle weight and gearing both in the transmission and rear axle can have a noticable affect on tuning and throttle response.

I did notice that my current ae-tps % vs coolant table is almost exactly what it is in your new start bin, the graphs are real similar using tunerpro compare vs what the start bin 2.0 and 3.0 had. Im not sure what else in the ae tables is different that would cause that change to work for both of us.