I'm currently working on the tuning for the turbo build on my Deathkart. I started the car project around 3 years ago, based off a 95 Camaro. I'm pretty familiar with all things car-mechanical, but boost and tuning is a new world for me. I've been learning a LOT by reading (and reverse engineering) in recent months and its cool world. It was neat to find this forum and its small collection of wisdom (something it seems is lost in modern forums). Huge thanks to "Skinny Pedal" for uploading his turbo tune that I could reference. A few pictures attached for fun.
www.youtube.com/watch?v=IPfetGYSSrI
Specs:
- All stock LT1 (other than cam)
- CC503 Cam and beehive springs
- Block hugger headers flipped and modified with all other exhaust being custom
- T76 eBay Turbo
- Tial 44mm Wastegate
- GT500 injectors (not yet installed)
- Shooting for 450 WHP to start... we'll see how long that lasts
Things I've updated so far:
- Tweaked open loop AFR for MAP scaling
- Tweaked Fuel Transient for MAP scaling (I noticed Skinny Pedal just did away with transient fueling all together)
- Took 5% VE off of crank eff table (for camshaft, this is a total guess)
- Disabled MAF
- Changed minimum spark advance to 15 deg from 4k rpm up (I noticed Skinny Pedal didn't change the default value of 23 deg)
- Tweaked main spark advance and extended spark advance
- Spark coolant temp correction updated
- Zeroed all EGR spark advance correction
- Low octane retard vs map
- Max knock retard
I've got several questions and will add more as I continue to tune. I'd also love to get feedback on the tune when I can get it uploaded.
- I've read about the barometric press reset. Sounds like most people zero this value but I've also heard to drop it to 1500 rpm so it continues to function out of boost. Which is preferred?
- What's a good target peak timing for ~8 psi of boost? Seems the LT1's really like timing, but I want to stay conservative.
- Right now its all on stock fuel system so I can make sure I can get the tune to run right with the 2-bar MAP (not changing too much at one time). What other tune values should I be looking at?
- Should I be modifying the BLM cell boundaries?
- I thought I had read there was a minimum injector pulse value somewhere, I anticipate I'll need that for bigger injectors?
- I've got a ballpark VE table for the camshaft from modifying based on fuel trims (its still on the MAF). Can I use these values once I do fueling mods and just halve the injector value I put into the ECM? (24.5 lb injectors for my 49 lb that will go in it)
Any help appreciated!
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Photo credit for the last image goes to my little brother who owns www.differentialimagery.com
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