Jon B.

^^^Just what I was hoping to hear. I'm already running Ken's chips with an S4 regulator and it's got an x-pipe and free flow duals after that. It's gonna be a wild ride once I go for boost!

I just need to see if I can't get some time up in Tim's neck of the woods for some good dyno time. I would think the tune will be pretty spot on from him though out of the box. I would like it optimized however.

Imo000

I'm the proud owner of that contraption!

Is this an optimal setup? No.
Am I leaving hp on the table? For sure.
Do I want to spend $2K on a Shakrtuner? Nope!
Is the car fast enough as it is? It sure is to me, good enough for high 12sec.
Is it a safe setup? I think it is. Always runs at the border of rich.
Do I want all the hp that this setup can give? No. Having a nice safety margin is wroth more to me than a couple dozen horsepower.
Is it possible to boost a 928 for less money than is cost to build my setup? I don't think so.

Do I want to line it up with Ted (Cosmo Kramer) to see who is faster? ABSOLUTELY!

inactiveuser1

Haven't heard anything from Carl in awhile on the stage 3 supercharger if that is coming out yet or not.You might also want to see what that does on horsepower.

Z

A few people have asked about the specific model of supercharger used on the Murf kits. It's a Vortech V3 T-trim. It's not shown on Vortech's web site with their other units because it's a model that's not generally available by itself to the general public. It's normally only available as part of a complete Vortech made kit for the C6 Corvettes. It's internally gear driven, uses the helical cut gears for quieter operation, and uses it's own self contained oiling system, so there are no engine oil supply or drain lines required.

Raptor's web site states that there's no warranty if the supercharger is used over 10psi. That doesn't really seem to leave too much room for upgrading unless a different model of supercharger is later purchased as part of the upgrade. I know Carl started out with a Powerdyne supercharger that had an internal drive belt on his track car. It kept breaking those internal belts when he increased the boost, and he ended up switching to a model of supercharger with internal gears on that car. The Murf stage-1 kits use the same Vortech supercharger that the Murf stage-3 kits do. That Vortech is rated to over 20psi, with a 1 year warranty.

The head gaskets are the great unknown. Tim's wife's car has been boosted for years, put on 10's of thousands of miles since being boosted, done countless dyno and road pulls, in temperatures from freezing up to around 100 degrees. It's still running fine with the original 24 year old head gaskets, even with 15psi of boost, and always having used only pump gas. Meanwhile, there have been newer, normally aspirated, completely stock cars that have blown head gaskets. Some head gaskets just rot away from improper coolant, the coolant not being changed regularly, or may not seal well due to something like the engine having been overheated at some point in it's history.

Custom cams would obviously help, but I know that there are some GTS owners with centrifigual superchargers and stock cams that are very happy with the performance. I think that whether they intended to or not, someone may have been using the cams as at least a little bit of a scapegoat in your situation.

There's really only one factor that will cause knock. That's too low of an octane to keep air/fuel mixture from igniting at the temperature that it's at. There are a number of factors that affect what the octane is, and also a number of factors that affect what the temperature is though. Keep in mind that even if there's no knock occurring at all, having the ignition timing set wrong can still end up causing damage to an engine.

The kits are supplied with a tune that should run well, make good power, and be safe for the engine. Cars can vary to some extent though, expecially if other modifications have been made to them other than the installation of one of the kits. A custom tune might gain some additional power, even if it's not absolutely necessary. There have been cars that have gone up to Green Bay from different areas of the country for custom tuning, a kit installation, or both.

SQLGuy

Just to throw one other thing out there, has anyone done anything on a 928 with a Procharger unit? They sound like they combine a lot of the best of both the Vortech and Raptor:

Gear driven
Self contained oiling in many models
Three year warranty
High boost
Billet case and impeller
CW or CCW

Pricing doesn't sound unreasonable either.

Of course, this is mostly from their web site. Is there a downside to these units?

blown 87

For me, I would much rather have one that is not self contained.

My D1 Procharger on my corvette has around 80,000 miles on it, nary a problem.

inactiveuser1

Seen alot of Prochargers at the drags some bigger units putting out 700+ hp.
Chevy is coming out with ZL1 Camaro in 2012 not sure what unit they are using.
6.2liter Supercharged probably will be another 11 second 1/4 mile street car from the factory.
http://www.chevrolet.com/camaro-zl1/...aro_zl1#image1

Cosmo Kramer

Thanks for that info Andrew, didn't know the EZK was that tunable AND that progressive. I will stick to what I know best

Perhaps Imre and I could build one of these and use it to check for inaudible knocks.

http://autospeed.com/cms/article.html?&A=0353

If professional tuners disable the knock sensors, how do they tune to ensure there are no inaudible knocks? Do they disable the sensors from changing the timing and just use them to data log knock counts?

hacker-pschorr

An experienced tuner knows how to find the limits and knock threshold of an engine long before the knock sensors pick anything up.

Everything from how the shape of the curve changes with various adjustments, to the smoothness of the run, logging hp/torque changes with every small adjustment etc....

I'm sure in a tuning forum this would be argued like oil threads, it's just the advice from Ben Strader when I took his EFI 101 class.

Watching a guy like Luke @ Beyond Redline really puts things in perspective and is why I don't tune my own car. Usually he tunes solo, he doesn't mind it when I'm in the passenger seat running the Shark Tuner. I don't question when he glances back and forth between 9-10 dyno runs overlayed and my maps in the ST and starts making fine adjustments. In between runs we also crank up the eddie brakes for some "rolling road" tuning. In a perfect world this is all you would do. Problem is heat, not only for the dyno but my last tuning day we had to take a break to allow my exhaust manifolds to recover from the bright pink color they turned. It takes a lot of fans to simulate 100+mph down the highway.

$120 an hour? IMO that's a bargain for his experience and know how.

When Luke builds a 700 awhp Mitsu, there aren't any knock sensors.

More of a precaution to keep them from interfering in case they are overly sensitive.

A while ago I read a story about someone tuning their engine. Instead of disabling the knock sensors he simply unplugged them. Bad idea since on most cars since this automatically dials in full retard. Once he had his tune dialed in and re-connected them, the maps he made were all multiplied by whatever factor those knock sensors adjust for. I'm sure this isn't the case with every car, just an interesting story.

I've seen the aftermath of too many engines destroyed from a bad tune. The blame game always points to something else....too much boost, bad gas, faulty injector, hot day, I wore brown shoes......never the tune. But when you look at the details and break down the data (or lack thereof) a bad tune is high on the fault list.

Carl Fausett

Dont confuse development work with production parts, please. As you stated, this was on a) my car, and b) racing. Thats how we learned what a Powerdyne could and could not do. I had to know what pulley combinations were best so I could recommend pulleys sizes to my customers.

Besides, your quoting something you saw in like 2005. We traveled a lot of ground since then.

Carl Fausett

For those of you that are unfamiliar with our Stage 2 kit for the Porsche 928:

Details are here: http://www.928motorsports.com/parts/32v_stage2.php

A sample of the installation instructions for this kit is available for download as well.

Our kits are shipped complete, with every nut, bolt and washer needed.

Here are some pictures:

Z

Todd up in Green Bay has a Procharger on his red car. It uses straight cut gears and is pretty loud. Here are a couple of threads on the car:
https://rennlist.com/forums/928-foru...ler-30psi.html
https://rennlist.com/forums/928-foru...tercooler.html

The Vortech superchargers that Tim used in the kits before the current ones did not have the self contained oiling system. The self contained oiling superchargers provide for a little easier installation, and look a little cleaner because of not having the oil supply and drain lines. I'm sure that if somebody wanted a kit using one of the external oiling supercharger models, it wouldn't be a problem to get one of those instead of a self contained oiling model. The brackets and everything else used is the same, so it would just be a matter of substituting one model of supercharger for the other, and providing the oil line parts. The external oiling supply models also use the helical cut gears, so are quiet like the self contained oiling models are.

"detonation is the first thing you should suspect when stress related component failure occurs!" - Smokey Yunick

Carl Fausett

I finished development of our Stage 3 kit several months ago, but have not posted about it.

The hold-up has been the supercharger head unit. Our Stage 3 kit is designed for modified 5.0L, 5.4L and 6.0 Liter motors. Because of this, we specified a larger supercharger than what we offer in our Stage 1 and 2 kits at present.

The supercharger has been a collaborative effort with Raptor to make up the 1200 CFM that we want in the package we need. The new Raptor is built around our patented impeller (more on our performance impeller can be read about here: http://www.928motorsports.com/parts/...neimpeller.php

But, the monsoon and flodding in Australia has hampered the manufacturing of these units for the time being.

I will post when I have a supply of parts, and final dyno results.

Here is what the finished Stage III kit looks like:

Z

Has it been that long already? I know that Powerdyne went out of business since then. The most recent pictures of your race car, with the stroker engine and new intake on it, show that it still has a gear driven supercharger on it. I do see that you have one of the Raptor superchargers on your GT that's pictured earlier post though. I see that those pictures are from back before you put the Electromotive engine management system on that car, which was a good while ago already. It's amazing how time has just flown by.

The new stage-3 sounds interesting. I see that the post above mentioning it does show the Electromotive engine management system being on your car. Is the Electromotive system going to be part of the stage-3 setup?

928mac

Hey Z that is post 928