415ci LS3 Upgrade - Dyno
I Like that number. I also like the torque curve. There are lots of badder cars out there than this one, but it will scare my skinny ****

Thanks to Phil and his gang at DTE!



I can't imagine what the corrected #s would be, but look at the area under the curve!
Congratulations on a great result!
GM
The under the curve really pleases me



GM
The Best of Corvette for Corvette Enthusiasts
My next mod will be a wide back/wide body with Z06 size tires.
For the board~
We didn't know what to expect when using this stock C6Z exhaust system on this package that we hadn't tested for in the past, as we've always used headers/exhaust in combinations like this. In any case, the results were very interesting.
That stock C6Z exhaust did prove very stealth in appearance, sound and fitment- to where if you didn't know any better, you'd think the car came equipped like that from the factory. Plus, the whole NPP thing is pretty cool unto itself and there's no match for the awesome, thumping C6Z exhaust note this thing belts out at WOT!
Additionally, the C6Z exhaust system does produce approx. 14 RWHP over the standard LS2 exhaust system from what we've measured, but it's still too restrictive for a big-cube stroker engine like this to breath properly and make big power. Just as a test, we dropped the exhaust pipes off the cats to see if the engine would gain anything and the engine *immediately* picked up another 7 more RWHP right off the bat... (which made the RWHP approx. 502 during that test) That led us to understand that the engine really needs headers to breathe well and to make the power target we are after when using such a small camshaft like we are..
However, the stock C6Z exhaust system did fit the needs of the customer to a tee for his visual emissions requirements and as long as he is happy, we are happy.
As far as what we see typically?
I've attached a copy of a past chassis dyno graph of our first R&D 415 ci. engine package we built last year to give you a comparison of what power figures we expected to see when the car was equipped (back then) with 1 3/4" long-tube headers, 2 1/2"" high flow cats, a 2 1/2" X-pipe, some sort of aftermarket mufflers with 2 1/2" inlets and stock gearing.
What we found then was that this engine design certainly liked headers, exhaust, etc.; however, it *really* needs to breath on the exhaust side with not only headers, but also having a matching camshaft, so the power curve will carry all the way to redline. This very reason is why we use headers on all our H/C packages we build here, combined with tiny camshafts- for which they all make approx. 470 RWHP all day long in the heat.
The only thing we've changed in our 415 engine combination from then (last year) to now with regards to header/camshaft design, is the header primary size has been increased from 1 3/4" to 1 7/8" and the cam profile was changed a bit to match, which gives up about 10 RWTQ in the mid-range, but picks up 11 RWHP through that same range overall as a trade-off- which is *exactly* what we wanted to see, since there is no shortage of torque anywhere in the power band with this package as you can clearly see. The engine likes "bigger" headers...
All-in-all, I'm very pleased with how everything turned out overall using these different, unorthodox components that aren't the norm. The build went very smooth, according to plan and the drivability/power this thing produces makes the car **REALLY** fun to drive- even for me and I've driven everything under the sun with variying HP levels over the years at one time or another..
The engine produces a *HUGE*, broad, flat, thick torque curve that makes it pull the nose of the car up everytime you step on it, producing 400+ ft.lbs. of torque from 2957 RPM all the way out to 6500 RPM- which is approx. 73% of the effective, usable power band!! A fun car to drive indeed!

I'll let John give his driving experiences of the car after he drives it, but I can tell you this from direct experience in building a **LOT** of these Corvettes over the years...this package is a *Home Run* in many aspects for sure!
Also, for those of you that will be at the Bash this coming weekend, you need to do whatever it takes for John to give you a ride in this sucker, because with the broad torque this thing makes, the only thing that comes to mind after a WOT blast is... "What the Hell? Holyyyyy Chit!!!!!"
Night all.

Best Regards,
Phil


















