PLatinum cobra, are you pullied? If so, what size, and what is your A/F ratio?
What A/F ratio are you guys running in your tunes
- Thread starter redfire03 svt
- Start date
PlatinumCobra said:
Just out of curiosity, what combiniations were these huys running? uppers and lowers? how much boost? KB, Whipple.... How many were just a 2.8, or 2.93, cai, exhaust, and tune?
IMHO these motors have cooling issues. If you are going to run high loads at high RPMs for extended periods of time you should address the cooling system. Water pump, radiator, etc... Increase coolant flow.
Ford needs to start using reverse flow cooling and cool the heads first, not the block.
Just my opinion and nothing more.
jim
Ford needs to start using reverse flow cooling and cool the heads first, not the block.
Just my opinion and nothing more.
jim
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redfire03 svt said:
I am not pulleyed, nor will I be. The next step is to go with a Whipple at 8-10 PSI and 11.5 to 10.7 at WOT. I don't think any more than 14 psi is good on these motors, period. That's just my opinion.
redfire03 svt said:
?? I'm just quoting the experts. It's not a matter of how much, it's a matter of how long. Many people on here will most likely never get their Cobras to 50K because they are toys or track queens. A pulley or 21 psi of boost should be no problem for these folks.
The remaining use them as daily drivers. All I'm trying to do is help DD people understand the risks they are taking adding 25% more RWHP to their cars. We just haven't had enough of these cars above 40K miles with mods yet, so it's too early to tell if pulleyed cars die sooner than non-pulleyed ones. Saying the motor will be fine is heresay. Other owners, like Lightnings, have the luxury of knowing what mods affect theirs as they've put the time in.
PlatinumCobra said:
I agree with you for the most part but I also think that this is what Coletta built these cars for.
PlatinumCobra said:
But do Daily Driver cobra Owners rag on there cars the entire way to and from work? Mileage is not a problem, mileage driving like a idiot is.
Here is my buddies car 25k miles 20k daily driven at this power level and tune.
NOT ONE SINGLE ISSUE WITH THE CAR AT ALL
I know this is just one example, but I personally know alot more owners with this same scenario.
BTW - what would be the point of a whipple @ 8-10 psi? :shrug:
Guys,
After reading all your comments, I have decided to get it pullied with a safe tune. I am going with Billet Flows 2.93 with the 4 idler setup and a LFP heat exchanger. If any have input on what heat ex it best, please let me know. To be honest, since this is my daily driver, I am only at WOT maybe once or twice a week, and it is usually a 2nd or 3rd gear run. I guess I baby the car alot. I never hit the track, so with my driving habits, and a safe tune, I should be good for lots of miles of fun right? 2.93 pulley is what comes stock on the lightning's eaton, so that makes me feel better too. But it is all about the tune. Actually that is how my 02 GT with a Novi 2000 blew up. Shot a rod right thru the block because of a crap tune. That happened after the blower been on the car for 9,000 miles with only 35,000 on the clock and kaboom. Not a nice way to go, and it was my daily driver too.
After reading all your comments, I have decided to get it pullied with a safe tune. I am going with Billet Flows 2.93 with the 4 idler setup and a LFP heat exchanger. If any have input on what heat ex it best, please let me know. To be honest, since this is my daily driver, I am only at WOT maybe once or twice a week, and it is usually a 2nd or 3rd gear run. I guess I baby the car alot. I never hit the track, so with my driving habits, and a safe tune, I should be good for lots of miles of fun right? 2.93 pulley is what comes stock on the lightning's eaton, so that makes me feel better too. But it is all about the tune. Actually that is how my 02 GT with a Novi 2000 blew up. Shot a rod right thru the block because of a crap tune. That happened after the blower been on the car for 9,000 miles with only 35,000 on the clock and kaboom. Not a nice way to go, and it was my daily driver too.
redfire03 svt said:
Good choice. Tune is everything!! :thumbsup:
marcseidler
New Member
I try for 12.0 with my LM1 TailPipe sniffer accross the board. That shoul dbe around 11.8 or so compared to a pre cat bung from the testing I have done on a dyno. I strive for this AF ratio on street runs. 3rd gear 1500 to 6500 rpm. This way it better dulicates real world use. On the Dyno the fans may not actually replcate the air moving with the hood closed, etc while driving.
redfire03 svt said:
My work here is done :beer:
Good Choice....and for the money I think $320 shipped the LFP Heat Exchanger is hard to beat.
All of your comments have been very helpful guys. One last quick question, if you use a tail pipe sniffer for A/F, does that read leaner than a precat sniffer, I ask this because I don't have cats, so would they read the same? OUr tuner the dealer uses a tail pipe sniffer. Peace!
One loud mouth spreading bullshit sure can ruin a thread...
If youre worried about your engine lasting 100k miles dont mess with it.
If youre worried about your engine lasting 100k miles dont mess with it.
Good call....redfire03 svt said:
mlambert said:
Who's the loudmouth? And what BS are you referring to? Please explain.
PlatinumCobra said:
Hey Platinum – in that chart that Jim Bell gives in that first link, I think he’s talking about non-intercooled cases. In those cases the extreme intake temps would greatly increase the chance of detonation so those octane requirements do make some sense. (Check out bullets 20 and 21 right below the table. That’s why I think he’s talking about non-intercooled scenarios.) All that changes with an intercooler, of course. For example, our cars run 8psi (or more) stock and only require 91 octane. Good reads! Thanks for posting them!
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Black2003Cobra said:
Thanks. That's a good, logical assumption. If you look at the two excerpts, you can probably assume 2 octane points lower with a good intercooler:
In the final analysis, intercoolers allow the engine to run 2-3psi additional boost on a given fuel octane.
That being the case, the chart would read more like:
92 9psi
96 11psi
100 13psi
104 15psi
108 17psi
Makes sense. 91 octane at 8 psi. :thumbsup: On the flip side, people running 12-13 psi should be running racing fuel or back timing off (which you lose HP), which is AOK. You'll probably get the best daily drivability at 11 psi and 91/93 fuel mixed with some racing gas. :thumbsup:
Yes, I agree. There seems to be a big convoluted relationship between boost pressure and inlet temps, fuel octane, timing and AFR when it comes to maximizing power while eliminating detonation. As I recall in that article written by the lead design engineer of the Northstar engine, he commented that to make the most power w/o detonation, it’s actually better to run a richer AFR and run more timing. (i.e., the power lost due to reduced combustion efficiency from the richer AFR is more than made up for by the power gained from the increased amount of timing you can run.) I’m pretty sure all of this is determined empirically. I know that MBT timing is, for example. I just hate the idea of being part of that experiment, LOL!
Black2003Cobra said:
That's interesting, especially since they're running super piggy rich, like 10:1 at WOT (after a sustained run of 4-5 seconds at a higher A/F ratio) . Good info!
I'd be curious to see if that's what Ford did on our setup. That would explain the ultra piggy A/F ratios on the original tunes. :read:
Yeah, I wondered about this. It would be nice to data log the AFR on a high-speed run on our cars and see if it drops after an extended period of time at WOT. I’d be surprised if the custom tunes do this though. I wish I had a wideband so I could try it. I have a stock-sized pulley for my hub and with the flip of a switch I can turn off my tune and go back to factory stock. Anyone else w/ a wideband want to volunteer?!
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