10-4 to that ^.

 

For those of yopu that do not recognize the screen name, this is Paul from Razors Edge. Normally I refrain from responding to these posts simply because things will be said and people will have their opinions no matter what myself or anyone else says.
This time however i decided to dispell some untruths and heresay.
Let me say that the 04 cobra being spoken of belongs to Mike keller whom by the way I just got off the phone with. The car came to me awhile back for a tune or should I say a retune as it was previously done elsewhere. The car made 17psi with a whipple sc. I tuned it and upon Mike returning to the track it picked up 6mph and 8ths. he called me and was obviously very happy. From there He decided to step up to 19psi, something we both agreed to do but still felt some caution.
Okay now on to the failure. This vehicle did in fact damage a piston but NOT from detonation. I like how statements are made such as " it had to much timing" or "it was too lean"with no facts or figures to substantiate the remark. The facts are this. Mike car left here with an A\F of 10.8-11.2 to1 and peak timing at 22deg. with the multipliers set to retard as much as 6 degrees based on A\f and or ACT. So what caused the failure????? if it wasn't lean and didn't detonate, hhmmm what could it be. Simple! the factory sets these motors up to reliably run 8psi of boost without using oil and to run as quit as possible. To do this the factory ring gap is set at 0.010.. For anyone who has built performance engines. especially blower or N2O applications this is way to tight at higher boost. Finally the answer, At high boost the temp causes the ring to expand. the ends butt together and have no where to go except to "flex" up or down ( 99% of the time they flex upward as there is little material between the top ring land and the piston crown) this causes the aluminum to push away. once that happens the resulting heat melts it, looking much like detonation.
I hope this helps to inform those who are concerned or were just plain curious. As a final note, I'm always here at the shop and welcome any calls or questions anyone may have. I'd always prefer someone call me for facts before a post is made.

Thanks for your time
Paul

 

We appreciate the remarks on the topic Paul, I still don't understand what the reason was for upping the lbs of boost to 19lb if you were concerned. I have seen cobra's run 21lbs of boost out of those cars with the whipple. I understand stricly performance does this on a regular basis.

Final word : I have heard of good tuning from REM and if this customer decided to up the boost with know the cocern from the tuner than he is at fault. But whe the customer said h ewen tgot a tune for his set up and was upset with the motor blowing after the tune than I am confused. So hear say comes from the horses mouth , not a tuner.

After hearing your side I can see it being customer error!

 

1fst54..Thanks for taking the time to respond and especially in a positive objective manner..It is appreciated. I'd like to address a few of your questions.1) the reason for upping the boost was that the customer wanted to and we felt confident in tuning it ( which by my prior post we did ) the conmcern is something I always have when going over 15psi with a twin screw blower. I feel that I would not be doing my job properly if I didn't have some concern for each and every customers vehicle. I know of many cars running over 19psi and many we have tuned with absolutely no problems. The fact is that the ratio of vehicles that have problems is small but there are those such as Mikes that do experience a problem and from this fact my concern always stems.
We have a local 03 cobra running 21psi with over 40 passes at the track with no issues at all, on the other hand I have another 03 in the shop with very low miles. The customer bought and installed a whipple himself and had it tuned elsewhere, it was set up for 15psi. This car has never seen a track or any top end runs but during one hard acceleration on the street the car "nosed over" and began to knock. We are building him a motor now so obviously we have seen the damage, it would have been easy to blame it on the other tuner etcc..but the fact is that this particular car did as others have, it butted the rings. The rings never got far enough to lift the ring land but it is clearly evident as the ring ends are polished from touching and there are witness marks on the top edge of the ring land wwhere the rings started pushing material up . Wheew I let this get winded...lol..sorry
I guess my point was that as a tuner\business owner and enthusiast we do everything we can to ensure a safe tune but unfortuneately somethings are just beyond our control.

Paul

 

Ok,thanks for all the input. After a lot of phone calls (most did not answer the phone or did not get back to me) I decided to go with JDM. THEY answered all my questions and where the only ones that could tell me how and what parts to use to take my stock long block to the max.

 

good luck.


I'm impressed with Wydopnthrtl's Truck. And I can tell you it is all from the tune.

 

Great post Paul. Good to know the 03+ motors arent indistructable because everyone and there mothers think they were hand built by god after they closed down the LS1 plant in heaven.

 

Paul at REM can throw out some good tunes, and works with his customers to get them right. On my latest tune (Thanks Paul) I ran a 12.83 @ 108.7.

Doesn't sound fast?

The density altitude was over 7 THOUSAND FEET.

That corrects to a 11.52 @ 120 MPH.