Tuning for TVS with Stage 2 Cams

[SACTX]

I'm going to be documenting and asking for help in tuning my car for the TVS with ZZP stage 2 Cams.

To start, my donor came with GM's stage 2 kit. Tune, 42lb injectors, and 80mm pully. I semi-tuned the MAF using the fuel trims as I was running up to 35% lean at times. It ran like a scalded ape after that.

The new mods will be as follows.
TVS with 2.9 pully
ZZP Stage 2 supercharged cams
ZZP 78lb valve springs and Ti retainers
ATI superdamper 5% overdrive pully
Bosh 60lb injectors (probably switching to 80's as I'm thinking they may be needed. I'd prefer to not switch)
OTTP boost referenced fuel system with dual supply lines.
1 step cooler NGK Iridium plugs

With this tune I'd like to get running on a MAF only tune and not nuke the motor before starting to get that tune dialed in.

I've been looking at videos on Goat Rope Garage and looked at other tunes. I have not been able to find any shared tunes with Stage 2 Cams so that part is a big question for me. I was able to find a tune running 60lb injectors with a TVS. I look at a lot of changes (mainly fueling and spark) in that tune and transferred most of them over. There were a bunch of changes in that tune under injector control that I didn't understand. It had "Flow Rate vs Volts" at 1.3 and there were a lot of changes to the "Offset vs Volts vs MAP" and "Offset vs Volts vs VAC" tables. I didn't change anything in these tables yet.

I took another 10% out of the timing on that tune to start and set the injectors flow rate vs. kpa to 63lb across the board. I kept the rest of the changes from the modified tune that I had before like MAF, DFCO, etc.

Any help on adjusting this tune to get the car running and fine tuning once it's running would be greatly appreciated. I know there are at least 3 other people planning on installing a TVS so a lot of what we do here will probably help them.

If anyone has a TVS running and would like to share their tune, that would also be appreciated.

I'm still about 2-3 weeks away from getting everything in and back together. I'm still learning so don't be afraid to call me out on anything that looks wonky!

My tune is attached as well as the TVS 60s MAF tune that I found and referenced (used) as a template for a lot of changes.

Thank you guys!

 

[Rauq]

I'm not on my personal computer right now so I can't open the tune files, and with the obvious disclaimer that I'm no tuning expert, here's my $0.02.

The data in the tune should be specific to your injectors, and is the first and most critical factor to get right in the tune. If the tune you're referencing has those same injectors, you should be safe. The Flow Rates vs Volts @ 1.3 across the board is a fairly standard workaround due to a limitation in the PCM regarding injector flowrates. I've read a few approaches but this seems to be the most straightforward (and probably the most correct) strategy.

If nobody has a better tune to offer up, I'd recommend taking what you've worked up so far and going another 10% richer just to dial it in from the safe side.

Do you have a wideband O2 sensor? Hat's off to you if you don't, I've tried tuning from fuel trims in the past and ended up caving and buying a wideband.

 

[SACTX]

I'm not on my personal computer right now so I can't open the tune files, and with the obvious disclaimer that I'm no tuning expert, here's my $0.02.

The data in the tune should be specific to your injectors, and is the first and most critical factor to get right in the tune. If the tune you're referencing has those same injectors, you should be safe. The Flow Rates vs Volts @ 1.3 across the board is a fairly standard workaround due to a limitation in the PCM regarding injector flowrates. I've read a few approaches but this seems to be the most straightforward (and probably the most correct) strategy.

If nobody has a better tune to offer up, I'd recommend taking what you've worked up so far and going another 10% richer just to dial it in from the safe side.

Do you have a wideband O2 sensor? Hat's off to you if you don't, I've tried tuning from fuel trims in the past and ended up caving and buying a wideband.

The tune I was referencing was with 60lb injectors. I didn't get the brand. Mine are the Siemens 60s. I was thinking the 1.3 was to bump it up to 80lb injectors but I also saw others using the MAF offset route to get the 80s to work. I just wasn't sure on that. I can go 10% richer on the MAF pretty easily. Better safe than sorry. That's also why I took 10% out of the timing.

I do have a wideband. I ended up getting the Bosch kit for the Aeroforce gauges that I have and I'll be able to tie it to the HP Tuners MPVI2.

Thanks for the help!

 

[Ross]

Unproven theory: Change the engine one step at a time, retuning the engine after each change, will result in a better ECU engine tune.
Why: To isolate the changes to the appropriate ECU tables.
I have been taught to tune the MAF & MAP tables, but those are related to airflow. If you change the injectors, these tables shouldn't need adjusting, as you changed the fuel system. If you stop and tune after that 1 change, you will dial in the ECU fuel tables for those injectors.
Also, I think I will reduce risk of engine damage, as I won't be make as big of changes to the ECU at each tuning interval. When you first make an engine change, you use math to guess at the correct ECU settings, then use tuning to change that guess to actual ECU settings.

1. I plan on starting with a properly tuned stock LSJ SC engine,
then adding the 80lb Bosch injectors
set the entire Injector Flow Rate Modifier vs. Battery Voltage table to be 1.6x (from 1.0x), but not tune this table.
then tuning the Injector Flow Rate vs. (intake manifold vacuum) KPA VAC table.

2. Make an E85 tune. I needed the bigger injectors to do this.
tune the Fuel/General/Stoichiometric Air Fuel Ratio to about 9.8:1 instead of 14.7:1 (I say tune, as pump E85 fuel is often E70 or E60 in reality)
research if I need to change any other values in HP Tuners.

3. Put on the 2.9" pulley on the supercharger
tune the end of the MAF Airflow vs. sensor Output Frequency table, as it should be able to get to higher airflow rates than before.
tune the Primary VE vs. RPM vs. MAP table, as the engine will be moving more air earlier in the RPM band.

4. Put on the 2.7" pulley
make an E85 2.7 tune. I won't be using this on gasoline.

 

[Rauq]

Ross does have the right idea here: you're going to put the best effort into tuning if your mods are installed and tuned for one step at a time. Fueling is probably the best place to start, and as we've said before, if you don't have your injector data correct, every bit of tuning is going to be band-aids on top of that. Compare the differences in the injector flows between your tune and your reference tune, so you know what all is changing. Then reference those changes with the data you have for your new injectors.

Ross, I'm thinking you may run into challenges with the 80lb injectors and E85 being separate steps- again, I've not tried it yet, but according to my understanding you may run into over-rich idle issues with minimum pulse widths on 93. Are you planning on running a BRFS?

Folks have talked about an E67 PCM swap on LSJs, which has flex-fuel capabilities including an ethanol content sensor. That interests me, but we're getting a bit off topic here. To bring it back, if it were me, I'd go fuel -> supercharger -> cams with tuning between each step. What do y'all think? Too much work?

 

[SACTX]

To bring it back, if it were me, I'd go fuel -> supercharger -> cams with tuning between each step. What do y'all think? Too much work?

At this point in my build, I pretty much have to do the supercharger and the fuel at the same time. I gave my GM stage 2 supercharger and injectors to Russell to install on his car. I have to do the 60's and from what I've read, they're easier to tune with the BRFS

That being said, I can reference the other tables for the 60's and set it a little rich for safety and dial it in from there. Get the tune right and then swap the cams. That's not a huge project to put off.

How would you address the spark advance since I'm making such a big change? From the tunes I've looked at, they're running a lot less advance than my stage 2 tune had in it. The only real advice threads that I could find mentioned pulling advance back to 10 or 11 and advancing it from there.

 

[Ross]

My limited experience with spark tuning is to start conservative, like you have, and then make small changes, say add back 1 or 2 degrees of spark timing, and go log some tuning data.
If you aren't getting any KR (Knock Retard, weird name, but if the engine starts sensing engine knock, it retards the spark timing) then add another 2 degrees. Eventually you will find the point that KR starts happening, and then you back it off a bit.

 

[Tinkles]

I highly recommend going with the 80# injectors from the start. The Injector Duty Cycle on my Cavalier(stock 2.2L Ecotec with a TVS and 3.15" pulley) is in the 70-75% window with 63# injectors and a upgraded fuel pump. With the ZZP cams and (assuming) stock fuel pump I would not be surprised to see your IDC over the recommended 85% cutoff.

I made a similar post years ago on J-body.org when I 1st tossed the TVS on. The PCMs/ECUs are completely different between the Cavaliers and Cobalts, but the rest of the stuff is relevant.

Harrop HTV1320 LSJ - Photos & Media Forum - j-body.org - The J-Body Organization

The J-Body Organization, j-body.org, is the worlds largest automotive enthusiast group exclusively geared towards the General Motors GM J-car platform including the Chevrolet Cavalier, Pontiac Sunfire, Pontiac Sunbird, Pontiac J 2000, Oldsmobile Firenza, Buick SkyHawk and Cadillac Cimarron.

www.j-body.org

 

[SACTX]

Nice Cavalier. I hadn't seen that before. Great write up. I was thinking that I may need the 80's instead of the 60's. I've seen a couple of dynos for cars with this set up (sans cams and pulley). I was hoping the BFRS would make up for some of that.

I've seen some back and forth about which 80's to get (don't remember if it was here or somewhere else). Anyone have the "correct" ones to get with the correct spray pattern in case?

 

[Ross]

I read an article on the HP Tuners forum, LSJ thread, that was explaining why the Bosch split spray injectors were better than the single cone injectors. I ended up buying the 870 CC Chevy Cobalt, Cruze Split Spray × 4 (Bosch EV-14ES) . Fuel injector connection claims they can modify injectors to be higher output, so you might just get your 60 lb injectors modified to be 80 lb injectors, and save some money.

 

[Tinkles]

870 CC Chevy Cobalt, Cruze Split Spray

These are 870 cc twin spray modified for the LSJ. They have a unique split spray pattern only available through us! Price is per injector. Part Number: FIC870SPLIT

fuelinjectorconnection.com

I have their 1300cc injectors on the shelf waiting to go in my build.

 

[ctuinstra]

870 CC Chevy Cobalt, Cruze Split Spray

These are 870 cc twin spray modified for the LSJ. They have a unique split spray pattern only available through us! Price is per injector. Part Number: FIC870SPLIT

fuelinjectorconnection.com

I have their 1300cc injectors on the shelf waiting to go in my build.

I have their split pattern 60#. Their injector data seems to be junk stolen from others. It was worthless to my dyno tuner. But since I have the BRFS, that simplified it greatly.

 

[ctuinstra]

I'm going to be documenting and asking for help in tuning my car for the TVS with ZZP stage 2 Cams.

To start, my donor came with GM's stage 2 kit. Tune, 42lb injectors, and 80mm pully. I semi-tuned the MAF using the fuel trims as I was running up to 35% lean at times. It ran like a scalded ape after that.

The new mods will be as follows.
TVS with 2.9 pully
ZZP Stage 2 supercharged cams
ZZP 78lb valve springs and Ti retainers
ATI superdamper 5% overdrive pully
Bosh 60lb injectors (probably switching to 80's as I'm thinking they may be needed. I'd prefer to not switch)
OTTP boost referenced fuel system with dual supply lines.
1 step cooler NGK Iridium plugs

With this tune I'd like to get running on a MAF only tune and not nuke the motor before starting to get that tune dialed in.

My tune is attached as well as the TVS 60s MAF tune that I found and referenced (used) as a template for a lot of changes.

Thank you guys!

So the SAC TVS tune file is yours? Are you currently working on tuning the MAF tuning? Why don't you want to allow for the VE tables? You will run out of MAF during boost. It's not uncommon to go the other way and run only off of the VE tables (once you get those set).

This tune is set up for BRFS, but you currently don't have one???

Did you want to turn off the ETC? Or just follow what ZZP does to trick everyone into thinking the tune just made the care more responsive. I tend to have a strong opinion on this one. May be I'm just a fool here.

If you are not currently MAF tuning, why not turn DFCO back on? Why have it off?

 

[Ross]

ETC, electronic traction control, I had to use google for this one.
There is soooo much jargon in tuning. It was my biggest barrier to learning from the forums. I was hoping to dumb it down a bit here... for me and for other noobs.

MAF, Mass air flow, a sensor after the air filter on our supercharged engines. Also the most common sensor used to calculate fuel for the engine.
DFCO, deceleration fuel cut off, used to stop the fuel injectors from throwing gas in the engine during deceleration, stopping the popping.
VE, volumetric efficiency, a method of calculating the fuel needed. Usually used when the MAF method has a brain fart, like sudden throttle changes.
ZZP, Zealous Zombie Pricing, one of the few vendors specializing in Ecotec parts.

 

[ctuinstra]

Actually in my reference to ETC, it was meant as Electronic Throttle Control. Yeah, I did a poor job of detailing and probably leaving a lot of confusion. More specifically, the Spark Retard for for the Torque Reductions is zeroed out. This effectively does not allow for retarding the spark timing in order to smooth out the throttle and help reduce traction issues.

 

[SACTX]

So the SAC TVS tune file is yours? Are you currently working on tuning the MAF tuning? Why don't you want to allow for the VE tables? You will run out of MAF during boost. It's not uncommon to go the other way and run only off of the VE tables (once you get those set).

This tune is set up for BRFS, but you currently don't have one???

Did you want to turn off the ETC? Or just follow what ZZP does to trick everyone into thinking the tune just made the care more responsive. I tend to have a strong opinion on this one. May be I'm just a fool here.

If you are not currently MAF tuning, why not turn DFCO back on? Why have it off?

That tune is the one I was working on as a base tune to get running. I already tuned the MAF with the GM stage 2 set up and was going to be refining it with the TVS. I had read that doing it this way would be better. I did not know about running out of MAF under boost. If that's the case, it's probably better to start from scratch. I did notice that the GM stage 2 tune was running Dynamic Airflow the entire time. Would that be why they tuned it that way? I did not change anything on the VE table from the tune that came on the car.

I do have the BRFS installed with the Siemens 60lb injectors.

The ETC was zeroes on the tune that I was looking over. I wasn't 100% sure what that did. Now that I know, it's probably better to leave it like it was.

DFCO is off because I had it off when I started tuning (I was originally going to start tuning the VE table and then read to do it the other way around to fix my lean conditions) and liked the popping exhaust It's off just for fun. I don't really care either way.

Thank you! This is exactly why I wanted help from someone with a lot more experience.

 

[SACTX]

Ok, so this might be stupid question. We don't have traction control anymore. So would it matter what the ETC vs. TPS or the Spark vs Torque Reduction are set to?

 

[ctuinstra]

Ok, so this might be stupid question. We don't have traction control anymore. So would it matter what the ETC vs. TPS or the Spark vs Torque Reduction are set to?

It still controls the throttle response during normal driving. And setting all of the values for the spark control to zero removes the throttle smoothing. If you like to drive it that way, that's fine. But on such a light car, the throttle become extremely touchy and sensitive with everything disabled. We have our set somewhere between stock and zeroed.

This is stock.

This is ours:

Now, above is just the table, but it's dependent on the Spark Retard table vs. % Torque Reduction to know how much to retard the spark to achieve the torque reduction.

 

[SACTX]

Gotcha. Yeah the throttle is already Extremely touchy In our lightweight cars.

 

[SACTX]

Finally got to be able to start the new tune yesterday.

After all of the comments and some messages, I decided to start with my last good tune (Modified GM stage 2) and not use anyone else's tune as a start. Thank you everyone for the input. Also, the MAF tune went a lot faster with the Wideband hooked up. It's amazing what happens when you have the right tools

The MAF tune is pretty well done. I ended up taking 2 degrees of timing out across the board after my 3rd run because I was getting some high end and lead in knock retard. I still had some knock retard that I don't understand and need to look up what that is. I didn't get all the way to the top of the MAF but I feel comfortable with it right now. It was getting a little rich on the top end which is not a horrible thing to have happen.

I'll be moving on to the VE tune today.

This is with the TVS and the BRFS. I have not installed the Cams yet.