Dramatic supercharger boosts & info in current Hot Rod Magazine Issue

[JimGnitecki]

The current issue of Hot Rod Magazine (September 200& has some interesting and noteworthy supercharger boost mentions.

On page 80, they talk about a Mustang GT (just a GT, not a Shelby) project car, running a Whipple twin screw superhcarger (not an Eaton like in the Shelby version) OBTAINED FROM FORD RACING PERFORMANCE PARTS, at 11 psi. (!!!) My examination of the entire parts list used seems to indoicate they did NOT do anything to strengthen the crank, rods, or pistons to take the 11psi. This is the second GT article I have seen where high boost (even higher as I recall on the other one) was apparently successfully applied to anengine with non-forged internals.

In case you are thinking that this is a Ford versus GM engine, and so maybe not applicable to GM engines, the other two references in this issue should get you thinking.

Starting on page 84, they document what well known builder Ken Duttweiler (mentioned before by 2005SSR6speed) has done to an 04 (not 05) GTO with the same 5.7 liter LS1 engine as the Camaro and Corvette had earlier. The article details the multi-step program that Duttweiler apaprently followed, and again makes NO mention in the parts lists of any crank, rod, or piston changes. On page 88, they say Ken ends up running 12 psi of boost on his STREET GTO. The article claims 539 REAR wheel hp, with the Magnuson 112 blower at this boost.

Then, on page 89, they show what happened when Ken changed to the 122 kit. THAT was a negative surprise. The [power only increase by 11 rwhp at PEAK, but plummeted everywhere else (theb larger blower lost nearly 50 ft lb elsewhere). Apparently, according to Duttweiler, this was because he could not get enough fuel to the engine, and had to scale back boost from 12 psi to only 8 psi. Of course, you have to ask why he din't simply go with larger injectors and larger capacity fuel pump . . . . ???

Two conclusions I have so far:

1. We MAY be able to run higher boost than we have been thinking in our cast piston and nn-hi-po rods LM4 (2003 and 2004 SSR) and (2005 and 2006) LS2 engines. Note that I say "may". I am not qualified to say, and I am not sure who is, but a Mustang GT engine and the Chevy LS1 5.7 liter engine in stock form are not by any stretch of the term "built" motors.

2. Duttweiler doesn't always get the predicted results, and sometiumes has puzzling questions in his results (this is not the first time I have seen that in his projects)

Lots to consider. But don't try 12 psi unless or until someone smarter than most of us says it will work for more than minutes or hours.

Jim G

[2005SSR6Speed]

Jim - Sorry, I somehow missed this post by you. The biggest thing to consider when bumping up the boost is that the tune is dead on. The stock pistons can handle alot of boost but they can not handle the heat and pressure together.

Tuners like Kenny Duttweiler are pioneers in the forced induction field. Kenny has been the best since the Buick GN days and continues to build unbelievable vehicles.

In order to run boost at those levels you need to make sure the Tune and the Fuel can support the boost.

The MP122 is a bigger blower and needs to be spun up to produce power and boost. Bigger isn't always better. The 112 is a great little blower that produces great torque and horsepower on stock size engines.

Another thing to consider when running that much power is that you will find the next fuse in the drivetrain. This could be anything from a transmission, drive shaft, axle or anything inside the engine that is not able to handle the power.

[poppa]

On page 80, they talk about a Mustang GT (just a GT, not a Shelby) project car, running a Whipple twin screw superhcarger (not an Eaton like in the Shelby version) OBTAINED FROM FORD RACING PERFORMANCE PARTS, at 11 psi. (!!!) My examination of the entire parts list used seems to indoicate they did NOT do anything to strengthen the crank, rods, or pistons to take the 11psi. This is the second GT article I have seen where high boost (even higher as I recall on the other one) was apparently successfully applied to anengine with non-forged internals.

What is the compression ratio of a stock 4.6 Mustang I believe that it is lower than an LS-2 that would allow the engine to withstand more boost wouldn't it

[2005SSR6Speed]

poppa - I dont keep up with the Ford engines so dont know what compression they are.

The biggest thing with the boost as stated above is the tune and fuel must support the boost you want to run. I know of a few that will run some real high boost numbers for bragging rights but cannt put more then 10 degrees of timing under boost. In this case you are not gaining anything over lower boost and more timing.

[Mike@Diablo]

The newer 3 valve Fords are at 10:1 cr right now.
There are lots of people running more than 7-8 psi on stock bottom ends.
I recently saw a thread on the GTO forums where a car was tuned with a APS TT kit at like 13 psi and made almost 600rwhp on the stock motor....like was said earlier, this can be accomplished as long as the tune is spot on and set up safely.
If you try to wring every last hp out of the motor at this point, it will not last, but a safe tune should be fine for thousands of trouble free miles.

Anyone thinking about trying this should direct their initial efforts toward finding a tuner that they trust and one that has extensive experience with forced induction.
If you call the tuner, and he says you need to lower the CR or that he 'could probably' tune it....keep walkin.

Thanks
Mike

[Mike@Diablo]

http://ls1gto.com/forums/showthread.php?t=180880

Check it out....

[2005SSR6Speed]

Originally Posted by Mike@Diablo

http://ls1gto.com/forums/showthread.php?t=180880

Check it out....

Mike - Nice read, thanks for posting that up. Notice all the upgrades to include the fuel system that were required to support that boost.

[Silver '05]

I use to run 17psi boost in my 1986 Buick GN with the stock engine, cast pistons etc. But your ride wont last too long with that amount of daily driven abuse. Your tranny/torque conv will probably be the first to complain if all is left in stock form. One thing that helped the GN live was the fuel mix went dead rich when the boost level was up. I had a Kenny Bell chip/tune

[TMZSSR]

A few months ago I bought a stock replacement fuel filter for my 05 SSR figured it might help fuel flow if the filter was starting to get dirty. When I openned the box and looked at the fuel filter I could not believe that that little wimpy looking filter with inlet and outlet tubes both at one end and look to be no bigger than 5/16 dia. if that could flow enough to support the stock engine, let alone ones that have been built for more power. Also the fuel filter on the 05 and 06 SSRs is inside of the gas tank, not an easy replacement.