Stock rod limit?

[svtl399]

The timing is stock due to making so much boost with stock internals. They had few degrees in it and laid down 440hp but decided to back down due to temp changes where I live and I do drive truck a lot. And im running stock upper pulley with a 6lb lower.

 

[WhiTriCobra]

Stock upper and 6 lower... You make 17/18psi? I made 13/14psi. Even cold temps would make 1 maybe 2 more. Def sure its a 6 lower? With a 8lb lower I dd mine too.

 

[svtl399]

yea I double checked and that's what is on it right now. On average is 15-16 but cool nights it hits 17-19 easily. My blower isn't exactly stock either. Steig has done some work to it as well. Shes whines pretty loud!

 

[JimIII@jdm]

Generally everyone who's commented is correct, however its detonation that usually causes the rods to break or other engine damage. Yes the Rods are weak, being a powder cracked design. Ford really should have considered a Forged Manley Rod like they did in the '03-'04 Cobras in hind sight, it would have saved them a fortune in warranty claims.

Around 450 RWHP is what I would call a safe limit. Providing your with in the range of your injectors and mass air. Much over that and your fuel pumps should be upgraded. I have had customers and seen many people online make up to or over 500 RWHP by having the proper sized injectors, mass air, fuel pumps, and a good custom tune.

1) Kick downs are your worst enemy as fore-mentioned. The stress it puts on these engines from the high torque output is enough to break the stock Rods.

2) Cold air will also play a factor because the engine is usually making more power you will max out the Fuel system (Injectors or Pumps) or the Mass Air Flow Meter. Once the Mass air reaches its 5 volt range limit the PCM can not calculate the proper fueling and you run lean. This causes detonation and catastrophic failure.

3) A Bad intercooler pump can sometimes be the culprit. I recommend to every Lightning owner to continually check theirs and make sure its circulating fluid in the intercooler system. If the pump stops working the coolant will not circulate and the Air charge temperature will raise drastically causing detonation.

4) Bad fuel, common sense tells you to run minimum 91 octane in a Supercharged engine. Some people may fail to realize this but its also possible to get a bad tank of gas. Go to a station that you trust. I also check after a new tank of gas to make sure the vehicle in question is not detonating. Bring the truck up to highway speed (55-60 mph) and slowly squeeze the pedal to the floor while its in OD (over drive). Be careful not to induce a Kick down!! While doing this have the windows up, radio off and listen to the engine noise. If you hear the sound of marbles in a tin can that's detonation and lift off the throttle, drive the truck easy and run the fuel out then get a fresh tank and try again. You would be surprised by how often this happens.

5) Get your vehicle checked on the dyno. A dyno is a tool not just something to tell you how much Horsepower your making. The dyno can measure Air Fuel mixture and plot it out over the RPM band giving you or your tuner the correct information about what your truck needs to keep safe. The Proper air fuel should be between 11.5-12.0 any much higher than 12.0 and its going to be on the aggressive side with the chance for detonation.

If you have any questions feel free to contact me via email [email protected] or by calling 732-780-0770 during our office hours!

Thanks,

JimIII

 

[WhiTriCobra]

^ for power adders, you don't mind seeing a 12.0 AF ratio? Seems like there would be no room for a hicup or bad gas or such. not knocking but if someone told me that in certain areas that a 12 was fine, i would pass.

 

[JimIII@jdm]

^ for power adders, you don't mind seeing a 12.0 AF ratio? Seems like there would be no room for a hicup or bad gas or such. not knocking but if someone told me that in certain areas that a 12 was fine, i would pass.

12.0 is the most we like to see, as a said any higher would be a risk. It depends on the vehicle and combination but yes on most Lightning trucks 11.8-12.0 is our target AF mixture. We have probably tuned 5,000+ Lightnings since 1999:beer:

 

[WhiTriCobra]

Ok cool, sounds good.

 

[Brad003]

Well sorry I havnt been on here but I went for my dyno tune Yesturday. Had miss fire on both half throttle runs at 75ish mph. Boost levels were 15.8-16.1. A/F ratio was 11.3 before miss fire on bank 2 then jumped up to 12.4 on bank 2. Shut it down both times. My tuner says its probably a bad spark plug gap on the driver side(bank 2). That I need to go get new plugs and gap them to .026-.028 or re gap the ones in it to them numbers and bring it back.

I don't have a ported SC yet, but once installed, will my eaton still be properly cooled with all stock cooling for it? Also, we are tuning it a tad on the safe side so the numbers will b a tad low. Not to much though.

WhiTriCOBRA, I have pm'd you about the ported blower.

 

[Brad003]

Also, my tuner said that he wouldn't recommend running that much boost threw stock rods. That 15psi or below is safer. What is the boost level that the rods can handle since it looks like 450rwhp is about the safest point with the rods. Cause people can be running different supercharges and less boost then a stock m112(which I have) and still make the same power as me. So just wondering what the max boost would be.