'03 Cobra S/C on Marauder

[JET]

I went to well know, Central Jersey, Ford speed shop to game plan my future mods. I brought info on the Trilogy and Reinhart blowers. The owner of the shop wanted to fit a stock "03 Cobra S/C on the car. Needless to say I didn't bite but I was wondering why or not use it? Looking forward to your thoughts.

[Zack]

It wont fit under the hood. Everything else will work as far as I know. The Trilogy car has a custom bellows that allows the height of the charger to be reduced for hood clearance. If you are ok with a cowl hood, go for it!!

[Dennis Reinhart]

Originally posted by Zack
It wont fit under the hood. Everything else will work as far as I know. The Trilogy car has a custom bellows that allows the height of the charger to be reduced for hood clearance. If you are ok with a cowl hood, go for it!!

Well it will fit under the hood its been done but you have to notch the engine subframe it will take a diferent wiring harness and you will be limited to very low boost, it may look nice but the power will not be there.

[Zack]

And there you have the correct answer!!

[Bowman9]

This is sort of on topic.

The intake on our cars was built and/or designed by Roush (according to the 2003 Marauder Brochuer) and the super charger on the 2002 SEMA Marauder S55 was a Roush/Eaton design.
So seeing that Roush has had a hand in the car from the start, how come they are not offering an aftermarket super charger kit???

Curious
Bowman9

[Zack]

Probably because only 2% of all Marauder owners upgrade their cars.

[BlackHole]

Originally posted by Dennis Reinhart
Well it will fit under the hood its been done but you have to notch the engine subframe it will take a diferent wiring harness and you will be limited to very low boost, it may look nice but the power will not be there.

Put the stock 03 Cobra internals in then the power well be there.
10 over 1 compression is not the answer but a 8.5 over1 is. So you can run 8 up to around 15 PSI with no problems.

[rurumon]

Originally posted by Dennis Reinhart
Well it will fit under the hood its been done but you have to notch the engine subframe it will take a diferent wiring harness and you will be limited to very low boost, it may look nice but the power will not be there.

Why would you be limited to low boost?

[Dennis Reinhart]

because the stock Marauder has 10 to 1 hypertectic pistons

[rurumon]

Originally posted by Dennis Reinhart
because the stock Marauder has 10 to 1 hypertectic pistons

What are hypertectic pistons? You mean pistons made out of hypereutectic steel?

Sorry for the questions dude, just figured it would help us all understand alot better. :)

[FordNut]

I believe the MM has hypereutectic aluminum pistons, while the Cobra has forged aluminum pistons.

[rurumon]

So i assume what you are driving at is that hypereutectic aluminum is weaker than forged Al. Why would this mean it could take higher boost from any other supercharger but not a cobra supercharger?

[Dennis Reinhart]

Just do a search on this topic The Cobra motor has 8 to 1 forged pistons thats why you can run High boost the Cobra has Manly rods and steel crank the Marauder has none of this, call me any time I will be glad to answer any of your questions

[RF Overlord]

Found this description of "hypereutectic" in an engineering forum:

Aluminum alloys used for pistons come in a wide variety, with varying degrees of copper, magnesium and silicon content. Though each element adds its own special properties to the alloy, silicon content is a prime driver in the overall characteristics of the alloy.

Hypoeutectic – 11% or less silicon content.
Eutectic – 12% silicon content.
Hypereutectic – Greater than 12% silicon content.

In the piston business hypoeutectic alloys are referred to as low silica alloys, while eutectic and hypereutectic are referred to as high silica alloys.

In short, hypoeutectic alloys posses a thermal expansion rate greater than typical engine block materials. This requires running higher clearances, which affect engine noise, wear and emissions. On the up side, these alloys are strong and well suited to extreme forced induction applications.

Depending on the method of manufacture, hyperteutectics may posses thermal expansion rates equal to (or less than) the surrounding cylinder, allowing tighter clearances to be run. Unfortunately they are brittle, and less tolerant to extreme cylinder pressures.

Keep in mind that the terms hypo/hypereutectic do not automatically imply that the piston was forged. Hypo/hypereutectic is only a description of the alloy used. Most OEM hypereutectic pistons are cast units.

[JHD7001]

The Cobra block is also cast iron vs aluminum on the MM.

Hyperutectic (high silica) cast pistons are generally a little lighter than forged, (cheaper production costs, reduces weight of reciprocating mass, frees up power & yields better mpg) but cylinder pressures created in a boosted application are too much for the structural integrity of the cast, they literally can crack & self destruct. Depending on the manufacturer, I wouldn't feel comfortable with more than 7-9 aftercooled psi on a cast piston motor, for longevity's sake. These motors are more like 10.3:1, if you do the math. That's really high to add boost in more than modest doses.

Just like the wheels on this car, the MM gets forged wheels, stamped out of a billet (big blob of aluminum) at 100's of 1000's of pressure per square inch, as opposed to (most oem & aftermarket inexpensive) cast wheels where the molten material is poured into a mold.

Cast or hyperutectic=weak, Forged=strong.

I really feel the Cobra engine assy swap is the way to go for long term big yield power. If I'm going to pull the motor for a build up, it'd have to be using a cast iron block. Why build one when you can buy one ready to run & sell yours in good condition?

[rurumon]

so then I assume for all futher boosted applications for the marauder it would be too risky given the hypereutectic pistons? That doesnt seem to make sense since the cobra runs 8psi and the aftermarket superchargers run about the same pressure. If the 10 to 1 pistons on the marauder can handle 8 psi from a vortech, how is that any different from the 8 psi coming from a cobra supercharger?

[MAD-3R]

I think part of it is the temp of the air comming in.

[cyclone03]

The Cobra engine is warrented to 60,000-100000 miles with a supercharger.
The Marauder is warrented without one....

Owners have repullied Cobras to over 500hp! how long before they go puff!? who knows but without the very heavy duty,racing, components installed it would be a much shorter time for sure.
I think the stock Cobra makes about 12psi boost.

Do a search of "Super Charger Wars" on this board.It may help.

[rurumon]

nope, I am positive that eaton blower makes a max boost of 8psi. So why cant the marauder take 8psi supplied by this eaton blower, how is it any different from any other 8 psi?

[BlackHole]

Originally posted by rurumon
nope, I am positive that eaton blower makes a max boost of 8psi. So why cant the marauder take 8psi supplied by this eaton blower, how is it any different from any other 8 psi?

First Aluminium Block for the MM vs. Cast Iron. for Cobra
and then the 10 to 1 compression for MM vs 8.5 over 1 for Cobra.

So if you put the Cobra internals in the MM block then you can get a long life out of the engine without it then it can go at anytime.

[FordNut]

Doesn't the Trilogy conversion use an Eaton blower? I believe they are making in excess of 8 psi boost with their setup.

[rurumon]

Ok, I can promise you that the Eaton blower makes a max boost of 8psi, check it out yourself.

Now, Im not trying to argue why the Cobra block can take greater boost levels than the marauder...that much is obvious. What I am driving at is that the couple supercharger kits out there for the marauder run around 8 psi of boost....so obviously our car can take 8psi on stock internals. Now, if our car can take 8psi from all the aftermarket kits being made for the marauder...why cant it take the SAME 8 psi from the eaton blower on the cobra?

No one seems able to answer this.

[JHD7001]

After having installed/tuned dozens of them over the last six years, I can assure you the Eaton is capable of way more than 8psi, the numbers are going to be relative to the application & charger size. I have had per-application stock units (no work to the housing or rotor group) putting out 11psi no problem.

I personally think the Cobra unit with aftercooler would be a nice match. I'm sure there are plenty of them out there for the picking when someone turbo's or KB's their Cobra.

The only drawback I can infer is the *instant on* nature of the Eaton vs the low initial, progressively increasing boost inherent with a Vortech. Less stress right off the line with a Vortech, but builds a head of steam like a freight train from midrange up, relative to pulley size & displacement of the application.

I was thinking along the same lines for my pokey daily driver F150 with the 4.2 V6. Architecturally the same as the 3.8 S/C TBird motor.

8psi on a 10.3:1 motor *is* different than 8:1 on the Cobra. Be careful, boost is addictive, once you have 6 you want 8, 8, then 10, etc.

So to answer your question, I don't see the difference between a Cobra take-off and another roots/whipple/positive displacement style aftermarket charger system.

[cyclone03]

Originally posted by rurumon
why cant it take the SAME 8 psi from the eaton blower on the cobra?

No one seems able to answer this.

I think what we missed was the above point,Your right theres no reason that the stock Cobra blower wouldn't work.

Except for fit.
I don't think the Cobra front dress will fit on the marauder engine,the lower pulley is caged,like the set up on the Lightening so the drive set up would have to be modified to fit.

The air intake is on the wroung side so you would have to make a new one,or modify the stocker to fit.

The intercooler would need to be ,you know it,modified to fit.

Then,injectors,fuel pump,computer tuning...........

Then the unknown.........
Will the stock Cobra lower manifold fit the Marauder engine?
Are the Marauder heads the same as the Cobra?

So it would be cool to use all stock parts to super charge a Marauder,but I think there's more to it than a simple swap.
Anybody got a wrecked Cobra I can take the top end off of to check the fit of the supercharger?

[rurumon]

thanks for understanding my flow cyclone. I was just curious cause it seems like it might be easier for one of our vendors to engineer a takeoff for the cobra system rather than create a whole new system...even if it means a new hood (which would be sweet BTW). Prolly be cheaper for the end user too.

[prchrman]

rurumon...good question...I get your drift...makes sense to me...

[notacop]

ok, to my best knowledge, we cannot compare a like quantity of boost from a positive displacement blower (eaton) to a centrifugal (vortech). it is apples to oranges. the nature of the eaton blower is so that it is running at near full boost by 2500 rpm, thus there is much stress on the engine at a relatively low rpm. a vortech blower, on the contrary, does not reach full boost until 5000-6000 rpm and even higher in some applications. think of it this way, we drive our cars in that 2000-3000 rpm window routinely, but (hopefully) only rev to 5k or 6k rarely. thus, a centrifugal (vortech) blower can be run on the marauder at a higher peak psi because the engine only reaches that peak psi on those rare runs to 6000 rpm (i.e. dragstrip) this is why it can be argued the vortech blower is better for the track, while the eaton is better for the street. it's all a matter of when and how a blower reaches its peak boost. hope this helps.