i am going to the dyno tomorrow with my 408 and i want to push it a little, not crazy but give it a nice test, crazy is later.

stock 6.0 heads, moderate cam, 8.8-1 compresion, t76, forged everything. probably run it up till i max out my 57lb injectors(66lb at my fuel presure), aprox 15psi i would say.

should i run the tr6 plugs i have in there or swap them out to some 7's that i have?

i am running a 50/50 mix of 118 and 92octane. any sugestion on how much timing would be safe? i wont have time to play with the timing so i would like to set it before i go and just leave it there. just play with the boost and fuel. right now it is around 20deg.

i will be tuning the fuel with megasquirt and i have the wideband targeting turned on. it prety much tunes itself but i watch to see what it is doing and adjust the ve tables a little so it doesn't have to make very wide djustments. i have it set at 11.8-1. everyone think that is a decent number to shoot for?

 

18 degrees timing should keep you plenty safe, 11.8:1 af is safe too. TR6's are suffice as well.

Good luck

 

-Run the 7's

-Timing. 16/17 deg @peak torque ramping up to 19/20

-Considering the weight of your vehicle, the engine will be highly loaded. I would run the a/f in the 11.0 range.

JMHO

 

This may sound funny, but everytime I go to my buddies turbo shop and talk about high octane, they talk about how they can run their cars at almost 13.0 A/F with like 20ish PSI. I know Race gas is great and all, but will it realy allow you to go that lean and be safe? These guys are doing it without failure. I was thinking about when I get my motor done, running low timing and just seeing how lean I can go before knock on 110. Might be something to think about also. With less timing, you can run less fuel, more timing more fuel.

Jim, your timing will be a product of how your cam is. I have a 224/232 116lsa in a procharged car we did. At 13psi, I was running about 20-21 degrees on 91 octane. So like someone else said, when your boost comes in, shoot for lower timing, then ramp up towards the end to keep the HP going.

Rick

 

my cam is a 234/232 ~600lift 115+1lsa.

probably wont be trying the 13-1 just yet. brand new motor and all.

 

13:1 is crazy for a turbo

 

please keep it in the 12.0 or below. and i would also suggest tr7s - just keeping it safe - and they pull the plugs and analyze. tr6 might be a bit hot for how much you are loading that turbo at what...close to 4800 lbs?

 

4800lb's is corect and on the dyno the load almost seems higher. it is a mustang dyno and holds the rpm gains back to 300rpm/sec. it seems brutal holding it to the floor for 10+sec but it should be able to take it.

so, tr7's, 11.8, and maybe pull a slight amount of timing around peek tq since i am at a flat 20deg.

 

Good luck Jim! Take some Video!
Will the 57's take 15lbs you think?
Looking forward to your results!

 

at 12.5psi in the cold i was up to about 80% duty cycle running right at 11.8-1. i think in a 70deg room there will be room to run a little more boost.

my single 3" downpipe is probably going to start holding me back now. that is on my list of things to upgrade.

 

only thing with those 7's.... watch out for them fouling up quick under normal driving / idle conditions. I guess you could tune around them being such a cold plug just saying keep that in mind. happened to a local guy here. great for the dyno, sucked when trying to actually keep it a street car.

 

With your C/R I think you can squeak a bit more timing.
I'd do 12.0-12.2, TR6, 19-21*.

P.S. My experience is with SC's.

 

I would get the A/F to 11:1, listen to jim, hes a great tuner

 

I like A/F at 11-1 but 10.5-1 on spoolup.Also lees timing at spool up is better.I would say 12-14 degree's midrange(spoolup) and start adding timing towards the top,max at 18. 408's like less timing than 346's do.

 

this is interesting, thanks for all the help. soo, tr7's, 18deg max, and a little richer than 11.8.

 

It's funny reading all this because difference types of car tuners seem to like to do things differently.

The GN people will sometimes run leaner at low RPM to get the AF up so it's hotter and aids in getting the turbos to spool then richens it up.

The import guys with WRXs, Evo8s and Audi's are doing it like Rick said.

Just interesting to see the differences.

 

I havn't run 7's, but I ran the same set of 8's all last year with no problems.

 

well, you are probably on the dyno by now but just another vote for 11.7-11.8:1 on air/fuel. TR6s should be fine

Let us know how it goes!

PS. I was just on a DynoJet dyno and although it isn't loaded like a Mustang dyno it was the Exact same a/f that I saw the night before when I tuned a little on the street. After seeing that, I think it is silly to load so much on an eddy current dyno.

 

I think Intmd8's suggestions are great because he factors in the load of the heavier vehicle. I run a bit more timing than you are being suggested but my raceweight is <3500.

 

I'm anxious to see the digits.