Johnson - 2005 LS2 Automatic - ProCharged Coupe - C6
As soon as I got my new C6 Corvette automatic I sent it to Shop XYZ
for a custom intake install. Soon after that they installed one of
the first 6 psi Procharger kits from ATI. Overall, I've been very
happy with the upgrades, but not with Shop XYZ. From the beginning,
I've had a problem with audible detonation at partial throttle and
under load at low RPMs. I did take it back down (300 miles) to Shop
XYZ twice after installation to see if they could fix the problem,
but all they could do is tell me a little detonation won't hurt the
motor. The car is two years old now and has over 48K on it, so I
became a little more worried about the detonation and it was a
little embarrassing with the car loudly pinging almost every time I
started under normal acceleration. Shop XYZ was one of the first
ones to be able to program the LS2, but they are impossible to reach
if you have problems, couldnít properly tune it, and made excuses
instead of fixing the problem.
Here's the good news. After coming to regret installing the system,
I found an excellent tuner who knew what he was doing. I highly
recommend Jeff Nance at Speed Engineering in Decatur
Tennessee. Jeff is a little laid back, but don't let that fool you.
He knows what he's doing and cares about the quality of his work. He
went out of his way to make sure I knew he wasn't saying anything
bad about Shop XYZ, but he did take the time to show me what my
problems were and explained what he did to fix them, as I watched.
Here are the four major points. First, he quickly fixed the
detonation problem, and then he showed me where Shop XYZ had made
the air/fuel mix so rich in some places it was off the scale. Then
in the low octane table, timing was so high that it could have
damaged the motor if I had gotten a bad tank of gas. Again, I'm not
a tuning expert, but the way he explained it to me made sense. He
also made the low RPM idle much smoother and safely pulled another
40 RWHP out of it. It now makes 500 RWHP SAE corrected and 512
uncorrected. During our all day and most of the night session, we
added a boost gauge, made two trips to the parts store, made over 12
pulls, and most importantly found and fixed the problems. I canít
recommend Jeff enough after almost two years of frustration with
Jeff isn't the least expensive place I have found and now I know
why. It does take an appointment to get a session with him, but he
knows what he's doing, takes the necessary time to properly fix any
problems and takes responsibility for his work. He fixed all of the
problems I knew about and even some I didn't know I had. He found
more power, made the car safer, and even made the car drive better.
These are the facts and I do have the documentation to prove them.
Jeff Nance's Speed Engineering and Dyno is one of the best!
Shop XYZ actual name withheld to remove the shop bashing effect.
Ken C6 - Nashville, Tennessee
Difference in a Custom Tune - 43.9 RWHP, 26.7 RWTQ - 2002 Z06
Corvette - C5
Well to make a long story short I bought my 02 Z06
November of '06, it had Long Tube Headers, performance x-pipe, Dual Borla
Stingers, and a Vara-Ram cold air intake, those were the only mods
that should make a power difference, unlike the B&M Short throw
shifter, and a couple other things. Come to find out upon the first
dyno pull the tune was not all that good, someone before I bought it
had been in the tune and changed a few things that took about 45
pulls on the dyno and lots of custom re-tuning to get it to the top
notch tune it is at now. Here are a couple dyno-sheet pics. This was
done to set a good base line before installing the polished Maggie
that is now being installed with the Methanol kit and MSD
Boost-A-Pump, and a couple other things as well. I did get to take
it for a ride after the last dyno pull, and what a seat of the pants
difference in feel compared to how it was, and I thought it was fun
before that. Many thanks to Jeff at Speed Engineering and Dyno, for
the excellent work and skill once again for me to be part of. Ron
Landry - Cleveland, TN
Landry - 1994 LT1 6 speed Corvette Coupe - C4
I bought this car with a couple of bolt-ons already in place.
I didn't feel like it had the power it should have so I decided to
take it to Speed Engineering to have it checked out.
This was my first experience with a custom tuning shop, and let me
tell you what a very good experience it was. Jeff got me a gain of
just under 30 RWHP with one custom tune and a few hours on the dyno.
I will definitely be back again and I highly recommend Jeff and his
services if you are wanting the Best. Ron Landry - Cleveland, TN
Tom Pfeifer - 2002 Anniversary
Chevrolet Camaro SS - LS1 - Automatic
When I took my '02 Camaro SS to Jeff I think I
presented him a unique challenge. I wanted a car that would fear no
Mustang and surprise a lot of Corvettes. To Jeff that in itself is
not a challenge. The unique challenge was that the car is my wife's
daily driver and must maintain the "from the factory"
manners, be tail pipe emission legal, naturally aspirated, and of
course a limited budget.
To make this unique challenge work there needed to be a very special
cam, torque converter, and tune. Jeff did the math and ran the
numbers and that is exactly what I got. A Speed Engineering special
proprietary small cam, torque converter, and tune all unique to my needs.
I gained 74 rwhp, 53 rwtq. It runs mid 12s on radials, gets 25+ mpg and the
wife can't tell the difference. It does all this while maintaining
the factory air box, factory cat back exhaust, and near stock
There are two words that separate Jeff Nance and Speed Engineering
from the rest of the other GM EFI speed shops "Mechanical Engineer".
Jeff is a Mechanical Engineering graduate of the University of
Tennessee. This gives him the fundamental knowledge and
understanding of how a automobile really works that the other guys
just don't have. Combine this with Jeff's years of experience with
and passion for fast GM EFI vehicles and you will come to the same
conclusion that I did. Speed Engineering is where you should take
your car. No where else could I find a shop that had both the
credentials I required AND was willing to do it my way.
Tom Pfeifer - Knoxville, TN
Thank you for visiting Speed Engineering and Dyno's
Testimonials Section. We
hope this site will help to show you what we can offer for your late model car or
truck. We offer many different services ranging from tune-ups to full
performance engine builds. If you want the best service and tuning possible,
then give us a call or send an e-mail. We will be more than happy to get you a
quote on any part or talk with you about a full package. No matter what, Speed
Engineering can meet your needs. Whether it is an aftermarket cold air intake, a
Speed Engineering custom built 4" cat-back exhaust, a 400 RWHP bolt-on only
X-Package, or a 427+ cubic inch blown monster. You have found the right