+1, especially with decent rods such that Porsche has. Crap happens but usually there's a reason and in this case it probably falls within categories 1-4 based on the OP's description rather than the absolute 700 whp number per se.

 

never heard of any tune, oem or the best tuner ever that has NO knock. There is noise, you just need to listen/see voltage. Just saying, no tunes with super high or even low power ever are completely knock free as in 0 knock counts, 0 voltage to the knock sensor/feedback

 

I should maybe clarify. With the GIAC software there are a couple things to keep in mind. For one, ALL of the factory knock control is still functional, with both the upper and lower FACTORY limits in place. If by some chance you get a bad batch of fuel, then the factory failsafes will intervene restrict power. Fuel was carefully monitored and 99% of the time this car ran, whether on the dyno or on the street, it was carefully datalogged to make sure knock was not an issue.

Secondly...with the GIAC software, "pump" gas is an entirely separate mode which is controlled by switching programs using the flashloader. Each mode is optimized for the particular fuel you're running.


No, we installed new Mahle pistons and Carillo rods. As I mentioned above, this car was carefully datalogged nearly every single time we ran it, whether on the dyno or on the street. The GIAC software suite allows us to monitor just about every single operating parameter of the ECU, with at least a few dozen channels that Durametric (for example) doesn't display.

You're correct bumper...with the GIAC software, all the factory upper and lower limits are left intact. This is why we use GIAC as our exclusive tuning partner.

Trust me, if the rods bent because we ran a batch of bad fuel, or the was knock present of any kind, the first line of my thread would have said "watch out for bad fuel", or "this is what happens when you have excessive knock"....but it simply wasn't the case here. Maybe this car had a weak engine, maybe it was built on a Friday...who knows. I only put this thread up to share our experience. Some people may run this power level and never have issues, but knowing that it COULD happen was what prompted me to share our experience. As a policy, I'm very open and candid about the research and development we do here. I have nothing to gain from posting this up, other then to simply share what's going on between our 4 walls.

 

"The engine i mentioned above making 635whp is on ethanol as is every car i own.. Ethanol will keep a motor alive with a poor tune longer than 93 octane will.. Its less prone to knock of course.. Its also dependent upon how you feed boost into the powerband.. If you have the HUGE peak of TQ that hits down low its more prone to hurting the motor and that has a lot to do with boost request.. "

..which is EXACTLY what I like about this engine; that you can get 950nm+ from 3000 rpm with VTGs. Hence i changed the rods to be able to get that. Like that you have 450hp at 3.5k and 600+ by 4.5k and its a blast. I guess with 3071s you can get even more, even lower..
Was running 670hp with 880nm with stock rods and nothing happened. We opened engine and rods were ok for that power level.

 

Ur still using GT2 intake manifold on ur car??

 

FYI, as far as I'm aware, all of the tuners that use the factory Motronics leave the OEM knock control intact. I know both of my Protomotive setups did, and I imagine EPL and SPI does as well. But the factory knock sensors only work up to a point. If they were truly infallible, you could run 2.0 BAR on 91 octane without any worries.

When tuning for maximum power at a certain octane level, if the tune isn't perfect or bad gas is used, all it takes is an over-advanced ignition event (typically caused by pre-ignition) or a detonation event to bend rods....knock sensors or not. Also, too much torque can cause it as well, without pre-ignition or detonation.

Not saying these are the only possibilities, but they are probabilities for sure.

 

I think knock sensors react to knock to limit it but they do not prevent it. Once knock is detected the ECU can pull timing and adjust fuel.

 

(going a bit off topic) Where can you buy ethanol in london???, closest pump is morrisons in swindon i think and thats e85

 

That's exactly right. They aren't infallible, and only help to a certain point.

 

xxxx

 

^^ Read this. The "speculation" was offered by the OP. To make 725 awhp on pump with vtgs is just not the same as A3076s. This raises further questions as to what pump program makes 725 awhp on vtgs???


<TABLE border=0 cellSpacing=0 cellPadding=6 width="100%"><TBODY><TR><TD style="BORDER-BOTTOM: 1px inset; BORDER-LEFT: 1px inset; BORDER-TOP: 1px inset; BORDER-RIGHT: 1px inset" class=alt2>Originally Posted by Tom@Champion
During it’s daily use and prior dyno testing, the car was running a pump gas program at 725awhp, which is what we’re confident caused the damage.




</TD></TR></TBODY></TABLE>

 

Thanks for your open candor Tom and sorry to see you get put under the hammer for showing the bent rods but a quick brinell hardness test to the old pistons (crowns and skirts/pin boss area) should put this argument of detonation to bed. Do you have a hardness testing device?

Have never heard that said before now. Must be some serious pitting to alter compression values?

Depending upon what industry sector your from, plenty of engine repairers out there that will reuse pistons (altho we personally don't). It often comes down to the mileage of the engine and the checks and measurements to the pistons that determines if replacement is necessary.

 

This is why with our current build we scraped the Porsche system and had Link design and build one. It uses sensors in all cylinders.

Here is post number 3380 back in January 2009 regarding this subject. It will help shed some light on the issue.
https://www.6speedonline.com/forums/...ml#post2678928

 

Paul, This is a critical bunch, you being one of them. Rods can bend, obviously, but more importantly what is the cause in this case? Too much tq, too high revs, wrong fuel on race file or is it really the limit as Tom implies? That's what folks are driving at. As you know, there are many 700+ whp cars out there on stock motor without bent rods. Cheers, Dave

 

No argument about that Dave!. And agree there are a number of 700whp cars put there without bent rods however, on a serious note, as there is quite a lot of speculation going on here If Tom wishes to provide me those numbers I can clear up for you guys whether the fuel or tune played any part in the bending of the rods. Engine and component failure diagnosis is one of our specialties. Provide me the numbers across all 4 pistons....Toms call.
PS. would also like a pic of the upper BE shells, lowers too. A report on the valves/valve seats and guides would also be nice along with how many KMs the engine has done....b4 and after tune. I'd truly love to get all the facts on how these engines really stand up to these high HP tunes over the cycle.