For pump 91/93 I would recommend the first set of mods as follows:
Throttle body
CAI
Full exhaust
NGK 3346's gapped at .035"
Next step for pump gas would be cams and 2.4" pulley, but I would not run the pulley without the cams.
800 SAE on CA pump 91:
- Thread starter Shaun@AED
- Start date
Throttle body
CAI
Full exhaust
NGK 3346's gapped at .035"
Next step for pump gas would be cams and 2.4" pulley, but I would not run the pulley without the cams.
Car may have made max power at 7,000 rpm, but the pull wasn't terminated until 7,400-7,500 rpm. I understand the need to find where max power is with the chosen components, but taking it north of 7,000 with stock internals makes the hair on back of my neck tingle.
While there are no doubt rod failures that happen at lower rpm, that doesn't mean the rod wasn't compromised during higher rpm operation. Powdered metal is not very forgiving. With the GT500, we're talking a very long stroke and the pistons speeds at higher rpm are extreme.
I completely agree with you. I'm not dismissing it at all. OPG will definitely save the motor in higher RPM's but a lot of misinformation is being thrown around lately that as long you shift at 6k-6,500k with mods on pump gas and keep power below 750rwhp then you're safe, which is not the case as you agree. Safer fuel like e-85, safe/good tune and OPG is what will keep these motors alive. Seems like from what Shaun has found with the cams moving peak cylinder pressure up in RPM that might be the go to mod along with other bolt on's for these cars.
A connecting Rod is a compression beam. The only way to break one is to have something uncompressable in the chamber or create too much cylinder pressure that hits it like a hammer (detonation). The lower in the RPM the cylinder pressure happens, the more time the rod is under heavy cylinder pressure, often with too much ignition timing to boot in engines like these.
Cylinder pressure is directly related to Heat and torque, it follows the torque curve. Peak torque is where peak cylinder pressure occurs. If you move peak cylinder pressure UP in the RPM it becomes far LESS likely to detonate as it has less time to do so, even if ignition timing is the same (physical time vs crank timing). (The flame front will burn at relatively the same rate at 2500RPM as it does at 5000RPM, but there is double physical time that the piston is being pushed UP by the rod after ignition.) Keep in mind the expansion of the gasses is not linear.
Why do Diesel engines have big massive rods if they don't make jack for HP and don't turn RPM? It's not about HP or high RPM, it's about Torque (cylinder pressure) at LOW RPM. High cylinder pressure at Low RPM is stressfull on connecting rods.
This GT500 setup on 91 octane is safer in this respect vs the same setup without the cams making less HP but similar peak torque under 3500RPM vs 4800RPM where this engine makes peak TQ.
The risk at high RPM and high HP is the heat generated closes the tight factory ring gaps and once they fill in the gap from expanding, they start to flex and can crack the crown of the piston. A piece of piston ring land between the head and the piston is not compressable, and will break a connecting rod, regardless of what it's made of or how thick it is.
OPG's need to be hit together in order to break, RPM alone does not kill them, aerated oil from the crank whipping at high RPM with a lack of oil control and banging a limiter, detonating, or lack of harmonic control (in order to shake the crank to bang the gears together) is what breaks pump gears.
Cylinder pressure is directly related to Heat and torque, it follows the torque curve. Peak torque is where peak cylinder pressure occurs. If you move peak cylinder pressure UP in the RPM it becomes far LESS likely to detonate as it has less time to do so, even if ignition timing is the same (physical time vs crank timing). (The flame front will burn at relatively the same rate at 2500RPM as it does at 5000RPM, but there is double physical time that the piston is being pushed UP by the rod after ignition.) Keep in mind the expansion of the gasses is not linear.
Why do Diesel engines have big massive rods if they don't make jack for HP and don't turn RPM? It's not about HP or high RPM, it's about Torque (cylinder pressure) at LOW RPM. High cylinder pressure at Low RPM is stressfull on connecting rods.
This GT500 setup on 91 octane is safer in this respect vs the same setup without the cams making less HP but similar peak torque under 3500RPM vs 4800RPM where this engine makes peak TQ.
The risk at high RPM and high HP is the heat generated closes the tight factory ring gaps and once they fill in the gap from expanding, they start to flex and can crack the crown of the piston. A piece of piston ring land between the head and the piston is not compressable, and will break a connecting rod, regardless of what it's made of or how thick it is.
OPG's need to be hit together in order to break, RPM alone does not kill them, aerated oil from the crank whipping at high RPM with a lack of oil control and banging a limiter, detonating, or lack of harmonic control (in order to shake the crank to bang the gears together) is what breaks pump gears.
With a BAP and injectors, yes. We also recommend a replacement fuel filter.
So without upgrading injectors/or using a BAP, can you do any mods and use e85 or would the stock system support e85 tune only?
No
Just quoting this for the excellent straight forward explanation from someone who gets it, not just a tooner
If I were local, I wouldn't hesitate to have you tune my junk man.
-J
Good point on the filter.
I run only ID1300s, KB comp BAP and upgraded filter up to 940rwhp on corn.
It's an important point, as I feel the factory filter is a restriction over 800rwhp.
Based on advice found on SVTP, I choose the Canton billet stainless CV filter (that you have to order with the correct fittings to bolt into the stock lines in stock location).
My tuner runs smaller ID1000s (or maybe FRPP 80s but I think IDs) and the same BAP with the stock filter and he was running out of pump at 850rwhp on E85.
Just a small point made for those going E85 and/or big power.
-J
All good points. Are you saying that most piston failures are the result of the ring lands butting together, because that's something I never considered?
I think you'll have a lot folks getting cammed with that explanation. But out of curiosity, what did you set the rev limit at in this tune?
Most see a hole in the block (rod failure) and do not do a proper disassembly/autopsy, some get it warrantied by Ford so we don't ever see what actually happened, but I have seen this be the case where the ring gaps were too tight and cracked the piston top which resulted in rod breakage. I had a guy send me pics of this a few months ago but can't seem to find them at the moment.
I also find it interesting Ford opened up the ring gaps on the 15+ coyotes vs what we saw on the 11-14's. .006-.009" top ring gaps on the older engines vs .012-.014" on the newer ones.
I have not disassembled a 13/14 GT500 engine to check rings gaps however.
Limiter is set at 7500 in this tune.
Boost ?
solid numbers.
Is this without a BAP? Can you get similar hp from a 5.4 with trinity swap?
Yes the car has no BAP all stock fuel system
Boost was at 15
Nice work! I have similar mods with L&M NSR Cams, just curious is their a way to tune out surging with the a/c on? With my a/c on coming up to a stop the motor will surge and usually stall...
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what don't you like about it?
I can tell you this about rods, they will stretch. Never had an issue with automotive rods but I have seen it in high hp outboards. Now we are talking about engines turning 10.5 to 11k rpm so that might have something to do with it but we had stretching. A well known engine builder in f1 racing would measure rod length every time the engine was down, which was every few races, as soon as the rods indicate growth they were replaced.
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