C6 Curtis

That's pretty rich with methanol on. You're leaving a lot of power on the table. On my Evo a while back I was at 11.8 afr WOT and I was spraying over 1000cc of methanol but I had a really good kit with aquamist. It runs on IDC and has a good failsafe that will cut boost.and bring IDC back up if it turns off. Only down fall with your kits is if you have a malfunction with your kit relying on meth it will probably cost you a motor.

-Curtis

Unreal

Maybe evos have better manifold distribution, but I wouldn't do that on a vette. If you are averaging 11.5 that probably means 1 cylinders is well into the 12s or leaner. LS manifolds have a pretty big split, and when you add meth it gets worse. I don't care about power on the table, it makes enough.

Maybe it is why I have one of the few 1000+rwhp cars that consistently runs and has over 20k miles on the motor.

schpenxel

lol, 1200rwhp and leaving a "lot on the table" don't even make sense in the same sentence for a street driven car.

Pitufina

Unreal, you must be doing something right to keep the engine together at that power level with that many miles. I've read a couple of times here and ls1tech that mid to low 10s on meth is not as bad as running that rich on regular gasoline.

Every engine is different and not all take the same timing to make power. I think the head efficiency, compression and cam timing can be the difference. I feel like I'm defeating the purpose of adding meth to my engine if I crank the timing to make more power. I rather increase boost than timing IMHO. I like to keep the octane safety window.

Unreal

Could it pick up 50rwhp from leaning it out? Probably. Is that worth it, not at all to me. Plus until I go with a direct port meth, I wouldn't run it leaner. Or goto a 8 cylinder EGT with individual cylinder control. Personally I won't run a heavy meth usage LSX motor over 11.0:1 as I wouldn't trust the lean cylinder to be getting enough fuel. I rather give up a little power and keep it together.

C6 Curtis

Well it never blew up and it was making 610whp on the stock internals over 6 months so it was fine. As for distribution I'm sure it is easier for a 4cyl to distribute then an 8 especially with the stock manifold, I'm not attacking you so chill out. That was a while ago I had an Evo. My Z06 is on E85 and I DD it. Holds up fine even with just about 14:1 compression with boost.
Yea it sure does and he knows it, he is just smart and has it reliable. 10 afr is pretty rich and getting it into the 11's will draw out more power but with meth it's a different story because it's sprayed before the throttle body it relies on good manifold distribution just as he stated before. DI meth is a good way to distribute it evenly but you lose the cooling effect.

-Curtis

neverstop

I'm sure you guys saw but on a ~1k whp setup Doug at ECS said they saw a >200* difference between cylinders using an 8 band EGT setup so the fuel distribution issues with meth on LS cars is real imo. not sure if the compression matters much in this situation but my motor is ~9.75:1

RicardoFors68

Wow, this escalated real quick, humbling discussion about meth use, or is it a dependency?

Unreal

I'm not upset or anything. Just saying why I like mid 10s. If it had a nice manifold or egts, or other options, I would have no issue doing it at 11.5:1, but I don't see the need.

neverstop

just thinking out loud about fuel distribution but if the car is, on average, at 10.5 afr and we know cylinder fuel distribution can be off on meth by about 250* based on EGT with a 1,000whp setup on dual M15 and I'll just guess "optimal" EGT on our cars is maybe 1350* so anyone cylinder could be off by ~18% (250/1350=0.185) so it could be possible for your leanest cylinder to be as lean as 12.3afr (1.18*10.5) which is right at the edge of where anyone would run a motor on the lean side.

This is obviously an extremely "quick and dirty" method to look at this which makes the engineer side of me cringe but based roughly on this I'd say that if you are using a big amount of meth on a >800whp LS car with stock LS style intake manifold that ~10.5 AFR is probably about right actually

chuntington101

It's funny but a lot of the turbo OEM cars out there will in erase the are to about 10.5:1 esp at higher rpm. These guys have multi million dollar dynos and do a lot of analysis. Unless you can prove your setup is rich and not going anywhere near dept. it's worth leaving a few BHP on the table to keep the engine together.

I'm with unreal on this, unless you can prove what's happening with each cylinder (individual egt, lambda or your read plugs like a boss) then why not tune it safe and enjoy it? If your tuner had to warranty it be would make it as safe as he could!

Streetk14

This makes me wonder what kind of methanol distribution I have spraying before the throttle body (i.e. through the rotors) on my Heartbeat TVS blower. I'd have to imagine it would be better than a stock LSx manifold, but maybe I'm off base.

I've always had the same theory as Unreal and some of the other guys in this thread as far as meth tuning goes. Both my LS3 builds and my blown LS1 build were in the mid-10's on methanol & 91 pump. My current car runs .80 lambda (~11.8) on the injectors alone, and I'd have to guess ID850s are pretty decent from cylinder to cylinder. It's always somewhere in the 10's with the meth active. Would leaning it out be worth some power? Probably, but it's not worth giving up the safety I have now. Even if I have some cylinder to cylinder inconsistency with the methanol, my relatively safe commanded lambda should keep me in the safe zone.

neverstop

I'd have to assume the blower helps with fuel distribution but I could be way off.

I think that makes a lot of sense to run it at 10,5 AFR with that extra point being added with methanol

RicardoFors68

Even though you guys are now speaking Chinese, i do see that ultimately im better off with meth for the safety of my engine.

veloz

just curious, anybody spraying in roots type SC? im trying to figure out if straight meth is the way to go or not with an eforce.

Streetk14

Yes...that's what I was talking about in my last post. I've sprayed methanol through 2 different Eaton based blowers. You don't get the cooling like you do on a centrifugal setup, but you get the octane.

I'd run straight meth myself. This is just a personal theory, but I think spraying a water mix through the rotors is more likely to cause wear than straight meth.

ProEFI

was running VP M3 here for now no meth and start breathing the C85

Turbo-Geist

I'll echo what a lot of you have already said. I ran in the 10.5:1 to 10.8:1 AFR range for a long time with 93 and 100% VP M1 methanol using 2 nozzles. It made 792hp @ 18 psi and trapped 146mph.

I then leaned the tune out later to about 11.2:1 and the car picked up about 40hp and felt a lot crisper throughout the power band. However, it ended up lifting a head and had a catastrophic failure.

Given some of the data out there comparing EGTs between direct port meth vs pre-throttle body injection, I can see how running things a little richer might increase reliability.

What's 40hp among friends?

neverstop

that's great feedback and sorry to hear about your motor. were you running dual M15 tips or were they the smaller M10 tips?

timmyZ06

Who are your "usual " meth suplliers??