I have a cam only ls1 that I will be adding a procharger and fuel system to. It's already tuned for the cam and I have that tune saved using hptuners. I'm about 6 weeks away from having all the parts and doing the install, but I'm reading books to learn how to tune as I look through the tune on hptuners.

I understand how to enter all the injector data data for new injectors. I've also learned about logging ltft and using that data to adjust VE. In my reading I've seen a lot about timing with boost using terms like "peak timing" or start low and work up, etc. I also understand there are other things effecting the actual timing besides the main timing table.

My my question is about what I may need to do with timing advance to make the car safe to drive before I even start logging ltft. It doesn't seem wise to just start lowering advance every where on the main spark table. I would assume timing around idle should be left alone since it's tuned for the cam and will not be seeing boost at that area anyway.

So what areas of the timing table table do I need to focus on reducing before I even drive the car to start logging ltft? Or anything else to make it safe to do part throttle logging?

 

take it to a tuner, you dont use ltft or stft especially when tuning a procharged vehicle.

 

Good to know. I just started reading on the subject and will not start tuning on the car if I'm not confident I know what I'm doing. I can always decide to haul it 5 hours to a tuner if I don't feel like trying it myself.

What I've been reading is that you log the ltft to adjust the VE table first.

I'm curious since you say I'm way off what are you suppose to do set the EQ ratio to give you the desired afr and make it go into PE?

I was thinking you had to have the VE table and maf setup correctly first.

 

His comment about not using trims to tune is based on the availability of inexpensive widebands for tuning. Many motors have had the tune "roughed in" based on trims with no ill effect. Many others have been blown up using the same method. The difference is some overly excited idiot making changes to the tune in large increments and flooring the throttle before logging much smaller incremental changes. To answer part of your original question, copy the low octane table to the high octane table for a safe start. Don't go into positive boost pressure until you have a better grasp of what is happening with your motor. As you read data logs, preferably with a wideband sensor and knock sensors working, you will gain a much better understanding of what direction to go with the tune.

 

Thank you for the reply. The low octane table has already been modified by the tuner that did the cam only tune so it seems like it would be way to much timing advance for the procharger.

Im using an aem uego it may not be the best but plenty of people have used them successfully.

Another question...with pe I changed the eq ratio to give me the AFR I want assuming no other factors are messed up to cause my actual AFR to be different. Which logs will help determine that stuff. The question is...should I be changing anything from the cam only tune as far as enabling pe such as map settings, or tps vs rpm settings to make or enable sooner or easier?

 

first off, you need to do a 2 or 3 bar OS upgrade.

 

Ok, I'm reading and learning more everyday and it looks like I'm best off to ditch the idea of keeping the maf.

 

From researching this topic it looks like I need 2 bar map sensor part number: 12615136

If I change to a 2 bar SD OS and change to that map sensor then I also need to change the linear setting and offset for the map. It looks like the offset will need changed from it's current 10.33 to 8, but I'm unsure of the linear the only thing I found searching was linear of 200.

At the minimum I need to be able to get it running and part throttle drive able so I can make sure everything is mechanically sound with fuel system, procharger, and no fluid leaks. It's a long haul to any tuner that I would want to pay to tune it so the last thing I want is to get the car there and have an issue that would prevent it getting a good tune done.

So to at least get it running from my research since I'm not changing anything except the fuel system and adding the procharger...

I install the 2 bar map and change the OS to 2 bar SD
Change the linear and offset for the new 2 bar map sensor
I copy and paste ALL of the injector data for the new injectors
I can also copy and paste the VE table from the current tune up to 105 kpa into the new SD OS tune.
Change the EQ ratio vs map in the boost PE table to give me the AFR I want under boost even though I wouldn't even be getting into boost while making sure it's mechanically sound just driving it a bit.
Change the timing tables to very conservative numbers in boost areas while leaving timing in idle part throttle areas alone since it will not see boost and current idle and drive ability is good with this cam.

At that point it should be running and driveable?

If I'm an idiot and way off base here don't hesitate to say so, but productive criticism would be most appreciated.

I'm looking to learn, but I'm also still at the point where I can decide it's more than I want to deal with and haul it to people that I'm confident in.

 

Your logical approach is sound.

2 Bar info is correct, hardest part will be getting the data for your new injectors (if you have that then all is good).

As long as you stay out of boost until you are a bit more confident the you’ll be fine.

Jim

 

I started tuning my own Procharged LS Monte after getting screwed by two local tuners. The best thing I did was have a base tune file made by one of the many mail-order tuners on here. From there (with help from people like Ed Hutchins, Steve Frost) I am now able to pretty much tune my own vehicle. Lots of patience is required cause you can blow your **** up quickly.

 

Multiply your entire VE table by 1.15 for a safe start. Don't use your stoich value to set your desired AFR that's what VE, PE and BE are for. Set up your OLSD AFR table to 1.0 (or as desired), or smooth your stock one out at operating temps. I use 1.0 for everything above 176*. Set up for OL. DISABLE ltfts. disable DFCO. Disable cat overtemp. Set MAF fail to 0. Set P101, 102, and 103 to MIL on first error. Set your PE to a rational number north of 80 kpa MAP enable. Set BE to 105. Set up your scanner to log WB, commanded afr, IPW, O2 mv, KR, dynamic, etc. This should get you on the road. Just did this like a month ago on a buddies car.

Ron

 

 

 

how did you go? how's the car drive? progress into boost enrichment and how much power did it make in what boost and what timing?