According to the chart, the maximum wheel horsepower is approximately 376.7hp using the stock AMG supercharger.

Does that correlate with people's experience?

 

That sounds about right.

What is the actual displacement of our unit anyways? 1.2L?

 

Found my own answer its a 1.6L. but that goes back to my point why not shoe horn a 2.3L or bigger compressor in there it seems many might be looking for more than the 1.6L can give them.

 

Well...using a larger compressor will increase compressor efficiency for sure.

It will also allow for people who port the heads, re-valve, install new cams, get new exhausts, intakes, remove the balance shafts, raise the redline, etc to make good use of their mods and get more power.

What that chart is saying is that with the stock AMG supercharger, no matter how much extra engine work you do, you are limited by the maximum airflow of the supercharger - about 380WHP.

 

By my quick comparisions the 2.3L flows about 30% than the 1.6L and while i agree with what your saying, when it comes to boost you dont even need to do head work cams and porting to gain more power from a compressor thats pushing that much more air through from my understanding.

 

Have to ask. what is the objective, just more, a specific power level, to what end?

If we go to a bigger supercharger where does it head? I have already hit the boost level where the computer threw a code, @ 25 psig. A bigger s/c will do that easier. More boost will also outrun the fuel system which I still have to control.

Sorta like chips and beer, you run out of one or the other and then you restock that one just to run out of the other, repeat. Add performance to one thing and then you have to correct for another. A bigger s/c would be really excessive IMO.

With the stacked pulley I can tell you that on street tires you cant drive hard on the street. Traction and drivability are two issues you can over-run quickly.

For more Zip I vote for a better rear gear that would reduce trap times and reduce stress on the $$$$ transmission. But how is that done?

Woody

 

I was just going to make a separate post on this altogether! I'll just stick it in here:


The first thing I researched once I found out we're outgrowing the stock supercharger is a post and polish of the S/C. This isn't possible though because the Lysholm unit has teflon coated blades. Now, looking at the Lysholm website(link above) we have a few options. Firstly, lets put our flow requirements into perspective:

A 2.8l whipple is a hot upgrade for the 4.6l 2003/2004 SVT Cobra motor. I would like this performance from our cars. So, 2.8/4.6 = .6086 This is our multiplier. Our engine is 3.2l so 3.2*.6086 = 1.94l or roughly 2l displacement from the blower. A 2.3l blower(like the lysholm options would be 2.3 / 3.2 = .71875 or the equivalent of a 3.3l blower on the 4.6l cobra motor. You would NOT want to go larger than this.

Looking at the blueprints of the LYS2300AX on the Lysholm website, I think it would work. Everything should right up the same, the only difference is that it is 50mm, or 1.98" longer than our blower. Height is the same, etc... The intake area might get tight around the firewall though. Another solution is the LYS2300R which has the intake on top(can you say more flow?). Same size as our blower, but may not fit under the hood because of the intake pipe that would now be going into it from the top. 2" hi-rise hood should fix this(or just cut it out like some of the vette guys with magnuson chargers).


Waldig, you have to remember that a larger supercharger is about airflow, not pressure. The LYS2300AX above will flow the same amount of air at 10-12 psi that you're flowing now at 21psi. And it will be using less horsepower because its in its efficiency range. So we have to upgrade the fuel pump to a Walbro 340, or swap injectors for say C63 Amg ones? We're talking less than $1k here. Good tuning will keep the fuel economy in check.


Lets ALL remember also that we are blessed with FORGED engines. I think 450-500rwhp on PUMP gas is certainly possible with the right setup. Switching to a turbo would overcome a lot of the obsticals we're seeing here, and allow a FMIC too. Think of the possibilitiess.


I'd also like to point out that as waldig said, a set of gears might be a good idea, although it seems that everyone is traction limited here(I haven't seen any posts of anyone running say a 275x60x16or17" slick). The stock wheels are also 59lbs with tires mounted. Flik makes very inexpensive wheels that are lightweight, and 17", might want to start there. Every lb of rotating mass is equal to 8lbs of static mass. drop 20lbs off your wheels and it's like dropping 160lbs from the car. The Porsche 911 GT3 even uses titanium lugnuts for this reason.

Another thing I've noticed is that I haven't seen anyone with an upgraded torque convertor. This makes a BIG difference in automatic cars at the drag strip. Much better 60' times which equates into faster ETs. I don't have any experience with torque convertor sizing in Supercharged cars, only turbocharged, but I would say something around 2800RPM should put a high 11-sec car into the mid 11's.


Food for thought.

-D

 

Quote:

Another thing I've noticed is that I haven't seen anyone with an upgraded torque convertor. This makes a BIG difference in automatic cars at the drag strip. Much better 60' times which equates into faster ETs. I don't have any experience with torque convertor sizing in Supercharged cars, only turbocharged, but I would say something around 2800RPM should put a high 11-sec car into the mid 11's.

The Torque convertor was mentioned during the SE florida tune. And that it would decreasev 1/4 times by a couple of tenths.

 

Right i dont see whats such a big deal about larger injectors and fuel pump. thats minor stuff to me. the 2.3L would put us at around that magic 500whp number so many were dreaming of 2 years ago. this and the torque converter would possibly push you into the 10's on pump gas. But as waldig said this would be more for the power junkies and drag racers, it would make the car no where near as drivable on the streets... to me thats a good thing .

 

Thats what im talking about
With a bigger blower you would need less boost

 

With the auction prices of SRT-6's at $10,000, and 30k mi examples available for $14-15k, it's safe to say that it a car that fast would be appealing to a LOT of people, and if it became common lpace enough, could actually increase the values of our cars later down the road(think Supras).

-D

 

Go Man - - Go!!

I look forward to seeing what you can do with your SRT6....

BTW - - The safe that's never been cracked is the ECU....N/A or SRT6......

 

what do you mean? I thought LET and InMotion do tons of great tuning?

 

377 here...dead on.

Quote:

Originally Posted by waldig

Have to ask. what is the objective, just more, a specific power level, to what end? If we go to a bigger supercharger where does it head? I have already hit the boost level where the computer threw a code, @ 25 psig. A bigger s/c will do that easier. More boost will also outrun the fuel system which I still have to control.

Woody,
Dont forget we can buy a bigger MAP and calibrate the ECU for it. Also, with a bigger s/c we should be able to make more power on less boost. Lastly, i still think a true return style fuel system is the way to go when we start to make big power and fine tune the fuel system.

Quote:

Originally Posted by Forza1

With the auction prices of SRT-6's at $10,000, and 30k mi examples available for $14-15k, it's safe to say that it a car that fast would be appealing to a LOT of people, and if it became common lpace enough, could actually increase the values of our cars later down the road(think Supras).

This is exactly what i have been saying. I think soon enough the only owners of srt6's will be performance enthusiest's...hopefully most owners will become members on this site, just like the Supra guys. No one owns a turbo Supra on accident, they bought the car knwing exactly what it was. In the next few years we will have all the bugs worked out and we will all own 11 sec monsters.

 

................before headers

 

By how much the air is cooled with the IC is difficult to say, because it depends on outside temperature, boost and the most important HOW LONG YOU STAY ON THE THROTTLE under boost. When I look at the diagrams I would estimate it is cooled down 50-60 Deg Celsius (120-140degF), when I compare it to my dataloggs.

The intercooling of our cars is only built for a short run to 250 km/h under full boost and then you drive 250 km/h with the throttle-body only "half way open". The car is at its limit only for a few seconds. For daily driving or 1/4 mile races (11-12 seconds full throttle) the Intercooling is good enough in my opinion.

 

With a bigger blower you would need less boost

THis is not true. THe pressure in the manifold is a function of the amount of air being SUPPLIED to the manifolds and the amount of air being TAKEN-IN. Add more air that you add, the more the pressure rises.

We at 21 psig are taking all the air that we can, and if you had a double sized blower at 12 psig, you would get LESS POWER due to the cylinders being filled less.

A larger s/c would provide more efficiency which would reduce the power needed to turn it. THis frees up HP. Higher efficiency would also decrease the heat load introduced to the intercooler, another good thing.

The air flow into the engine will dictate power if the fuel issues are covered otherwise. Our motor is just a heat engine, and the more air that we warm up the higher the cylinder pressure pushing down on that con rod.

I have a really neAT project going and I have bet another member of the forum that I can increase the flow in his manifolds by about 40%. This is without changing the laws of physics, but that wont be done for a couple of months.

If I can prove my concept, then my measured boost at the manifold should be another psig higher again, without additional work on the s/c or pulley system. Air flow is all about its velocity and pressure differentials driving it. Its sorta like the discussion above; referring to the lower restriction double CAI inlet.

Yes the torque converter could be an improvement, I have had a custom one or two made. The MB name would make it costly, we had some looking into this and I have not heard more of them. A better rear gear with real posi would be hands down the best in my estimation.

Stupid is bone deep though: http://www.youtube.com/watch?v=SsOK-TCJoKo

Woody

 

The problem has been when adding FI or changing charging systems. There have been countless people/companies that have tried turbo systems, twin charged systems, etc, but they just haven't been very successful. Some have made it work, but they are one off systems that are almost impossible to duplicate and/or cost a fortune. And most of them have never really gotten it to run consistently.

The one thing that has seemed to work is actually swapping engines and engine management systems. Instead of looking to change the charging system, I would look to swap motors. You say, "whoooooooaaaaaaaaa, talk about expensive!!!!" Wrong. I would bet that you could actually do it cheaper. You can find an engine from a salvaged vehicle that is very cheap, in near perfect condition, with very low mileage. I would bet the SLK55 engine would fit in the Crossfire bay with few modifications. This engine could easily make 450 to 500hp.

 

Take it another step farther and put an E55 motor in the 6. They share the same tranny. So just the motor swap.

 

You guys may want to rethink that engine swap, lots of fun reading here that seems to have never made it to completion.

https://www.crossfireforum.org/forum...ad.php?t=18481