MBT Without a Dyno

[mcleansc]

Hopefully some of the more known tuners can pitch in here. I'm trying to squeeze everything I can out of my stock turbo drag car and with 430whp and 21psi on 99RON id say I'm capped out.

I've been thinking of running 120RON leaded in a bid to run more aggressive timing as I ran 0.5 of a sec faster with an OTS E50 tune vs 99RON. It's a track car so price (within reason ha) and the O2 sensors wearing quicker isn't as issue as it does like 100 miles a year. Here's my idea: run 120 then dyno. Send log to tuner, they table trace the cells I'm in on the WOT pull and add a bit of timing. Dyno again . Overlay the new torque curve with the old. If it's making more torque across the whole curve I repeat (table tracing any dips). Do this until the torque curve stops improving or until I become knock limited. I won't get MBT across the full map, but I will where it matters.

Would this work? And is it worth it?

 

[carabuser]

Slowly adding 1* and checking for knock each time would work.

The torque gains start to level out after 14* on E85 from other testing that I've seen. But then that might be more an issue of fuel injection timing due to the additional volume needed.

Cylinder temps will be quite high with stock turbos spinning flat out, also you don't have the cooling of Ethanol.

 

[mcleansc]

Slowly adding 1* and checking for knock each time would work.

The torque gains start to level out after 14* on E85 from other testing that I've seen. But then that might be more an issue of fuel injection timing due to the additional volume needed.

Cylinder temps will be quite high with stock turbos spinning flat out, also you don't have the cooling of Ethanol.

I completely forgot about the burning cooler with Ethanol thanks for that. I was getting too caught up on the limitations of the fuel system so was leaning towards race gas. And the fact I don't need to blend it. I might switch to E50 or try E85 again in that case for my current power level.

Do you know of any known tuners who'd be more open to working with me on this? I imagine there'll be a number of revisions and long delays between Dyno time.

 

[carabuser]

I don't think you need a tuner if you already have an unlocked map, you'll only be modifying the main timing map.

Best to just make multiple copies of your current map and increase the timing during WOT in each iteration. So start with a map with a peak at 8*, then move up in 1* increments until something like 16* then just run each map and check the log data, if it looks good, load the next map and run again.

Just be careful about letting the water pump stop before downloading the next revision as it will run coolant through the system after the engine is turned off and a download to the DME will inhibit that.