atlsupdawg#2

Thanks for the welcome Todd.. To be honest bro, it's more of a "budget thing" that I've set for myself.. Plus I promised the ole' lady I wouldn't go overboard with this car. Hence the decision to go with the Turbonetics. Hell, fabricating a system isn't necessarily out of the question as well. I'm really not cheap.. HONESTLY ...I just try to enjoy the hobby..

etx

Dead on, that was the fate of my stock motor.

Badfish25

iTrader: (3)

The 05's have stronger rods? Is this all 05's or just the 300 hp 05's?

Sharif@Forged

iTrader: (92)

Just the 05 300hp motors. Although the part number for the rods and pistons are different, we dont actually known how much stronger, or even if they are stronger than last year's. They could have done things like shave weight, modify profiles, etc. It's impossible to know.

Brandon@Forged

Weigh them and then pressure break them. Then we'd know which are stronger, if either are. (the rods, not pistons)

atlsupdawg#2

Man nis, that stock rod and piston in your sig look "scary" thin bro..

Brandon@Forged

Sure are.

BriGuyMax

iTrader: (4)

That's partly because you're looking at it next to an extremely overkill Pauter rod.

I'd also pick up some ARP rod bolts when you do the cyro treating. IMO the rod bolts are the weakest item on the bottom end and have led to the rods being blamed for many failures.

350zDCalb

iTrader: (21)

IMO (and pretty much everybody elses' as well who has actually built their motor)...there is NO SUCH THING AS OVERKILL when you are building a motor and running forced induction!

and, as far as the rod bolts being blamed...haven't you seen, picture after picture of these rods being bent and twisted? they cannot hold the extreme rapid increase in torque produced by high boost TURBO kits (superchargers are so linear-this isn't an issue)..to say it is the rod bolts is like saying "the reason the guy broke his leg when he jumped off the skyscraper is because he wasn't wearing jeans"...come on now

for example: with my current setup (granted I'm probably running more boost than one would plan on a stock motor)...my torque numbers from 4200 rpm (approx 320ft lbs) to 5500rpm jumps (537 ft lbs) ---that's over 200 ft pounds of torque increase in 1300rpm range!!!

just my oh so humble opinion

atlsupdawg#2

BriGuyMax, I definetly have to agree here. A lot of the pictures I've seen are of either busted up pistons (ring lands) and/or mangled rods. The rods obviously sustain a brunt of all the forces. They contend with the forces exerted, ultimately, by the tires and drivetrain and also the upward motion going from BDC to TDC. Everything is transmitted through the rods....I also see your point as well...When you combine the increase in power and inertial forces on the rod and piston, you definetly want stronger rod bolts to keep everything together. I've seen one motor, a 2JZ-GTE, that was totally destroyed because of rod bolt failure. Albeit, this certain individual bumped the rev limit up to damn near 8000 .

350zDCalb

iTrader: (21)

fortunately when you get beefier rods...the rod bolts will typically (in the case of pauter-always) be very high strength quality hardware...

don't know why but this reminds me of the joke...i survived blank and all i got was this crappy t-shirt

"I blew my motor, did forged internals, and all i got were these arp rod bolts"....ok, i'll stop now

Sharif@Forged

iTrader: (92)

^^^Agree as well^^^

I have yet to see a rod bolt failure. Plenty of cracked piston ring lands, and twisted/sheared rods...typically near the wrist pin area.

With F/I and moderate reving applications, such as the VQ motor at 7000rpm or so, strength takes priority over weight. Unless I was building a very high revving VQ "which would be counter-productive, since the VQ's bore and stroke doesnt lend itself to very high RPM operation), I would choose the beefy Pauter rod.

BriGuyMax

iTrader: (4)

So please explain why the majority of motors that blow up do so WELL UNDER 400whp...

By your theory all the APS TT'd cars with over 400whp on the stock motor should be blown up by now. Same for all the Greddy kitted cars with well over 400whp. But that's not the case. A vast majority of the cars that have OVER 400whp stay together without a problem.

The reason you're seeing rod failure is due to many more factors that simply the strength of the rod.

I'm not saying that the stock rods are anything special, just that most of the pictures you see of broken rods aren't due to stress from power output, but detonation and heat.

BriGuyMax

iTrader: (4)

I totally understand that the rod takes the brunt of the power abuse...and the rod bolts are more sensitive to revs than power output, but from what I've seen the rod strength isn't the issue in the mid 400whp power range. People like to blame it on the rods...it's become the "cool" thing to do around here. But I think they are falsly being blamed for a tuning issue with the stock ECU. It's the extremely sesitive tuning that's involved in the situation.

Brandon@Forged

I agree.

Sharif@Forged

iTrader: (92)

Stronger forged internals give you a higher margin for error. When tuning these cars, they tend to run near the brink. Of course, with the coveted "perfect tune", I bet stock rods could reach 550whp or more. But the fact is that a perfect tune is extremely hard to maintain for any period of time.

Even stock rods can take a tremendous amount of uniformly building cylinder pressure. But at these levels, the slightest detonation can damage bearings, pistons, and rods...so the failure rate increases. Our factory rods are some of the wimpiest I have seen. They are not designed for forced induction. They are designed to be light weight, and allow the motor to rev freely for N/A operation. Adding F/I increases the changes of failure. Our cast pistons are also pretty junky, so we see a lot of shattered pistons and cracked ring lands. I truely believe the pistons are weaker than the rods, but while you are changing one, you might as well change the other.

Bri, I dont think doing forged internals is the trendy thing to do. I think it is prudent for those looking for 500whp and beyond. I have never suggested that people upgrade their pistons/rods at the 400whp mark. Instead, they should focus on maintaining as perfect a tune as possible. Our original motor had 14,000 very hard miles at 8-9psi, without even a trace of damage to the bearings or pistons.

350zDCalb

iTrader: (21)

-tuning,
-possible ECU switching timing maps,
-use of a piggyback system with an ecu that demonstrates adaptive learning at all parts of the map (or something that causes it to change-gurgen can explain this much better than me)

true, many factors will cause these motors to fail, but this was not your point...you were claiming that the rod bolts were responsible..this is not the case...many factors are responsible...primarily the tune (this does not mean putting the car on the dyno and plugging in numbers, because i have seen that change in a matter of days)...i believe this is the MAIN reason so many e-manage tuned cars have blown...the tune can be perfect on the dyno..needs to be watched closely and fine tuned for a few days/weeks to ensure it is consistant and one is driving around with the same tune they think they are--this further shows the importance of a wideband A/F and an EGT guage onboard to continuously monitor the tune

you ask why the APS setups have lasted above 400whp...it's not the number 400 that is so magical, it is the fact that these setups are not tuner friendly..they come with a preprogrammed safe map and addresses fuel AND TIMING <---(KEY)... when people can't mess with the tune and the tune is rich and safe and DOESN'T change (or at least addresses timing-many greddy kits blew while not pulling any/enough timing) the longevity is much greater..

these motors will break rods as well, because these rods are not strong enough, it's just a matter of time...the pauter rods and forged (super duty) arias pistons give much more forgiveness when it comes to a lean mixture...they survive small amounts of detonation because of their pure muscle, unlike the stock setup that will snap like a toothpick (i know i'm exaggerating, couldn't resist)

I'm going to bed, hope that served as a descent rebuttal BRIGuy

GurgenPB

iTrader: (2)

^^^ Agree

The tuning really is key here; at least 90% of it. But it is NOT the only factor. My stock engine failure was due to a rod bolt failure (most likely), and I am thinking that it was due to my increased red line, and my making use of it quite extensively (before the TT went in). I ran above 6.5 psi only about 4-5 times, and even then with a very very safe tune, retarded timing, and a J&S safeguard watching my back. But when it went, it went. The blown engine had no sign of detonation in it, it was otherwise in a very good condition. The bottom half of the big end of the #3 rod was 'peeled' away from one rod bolt to the other, straightening that round bottom half of the big end of the rod into a near-straight, banana-like shape. The other alternative is that this engine was just weaker to begin with, especially weaker main studs, which stretched and allowed the rod bearing to spin and be an equal culprit to ripping hte rod bolt apart. Whatever it was, it DID positivley result in, or WAS to begein with, a rod BOLT failure.

350zDCalb

iTrader: (21)

woh....that's the first description i've heard of a motor blowing being tied to the rod bolts
this can definately happen in theory (and you proved it)...i assume the MAJORITY of the time, the rod bolts are not to blame--in my case, the rod bolts were still intact..the rod twisted horribly and the piston was in a million pieces.

atlsupdawg#2

WOW, make that one I've seen and one I've read about..
What you describe about your rod failure was EXACTLY what I saw when we took the motor apart. You'd have thought the piston got seized in the bore and the crank just ripped the bottom end of the rod off.