vrus

Grumpy,

I selected the LS1 because that is something I was familiar with. You are wrong about the power band. An LS1 with a Magnuson blower has a very BROAD power band and a FLAT torque curve.

The FLAT torque curve has been my ultimate quest from the beginning.

When I said efficiency, I meant efficiency in general (thermal, volumetric, everything). I have to blame it on efficiency. I don't know the exact cause otherwise I would have stated it. I am just trying to open the topic up for discussion.

What other reason is there for us to have to run twice the boost to make similar power? There is an efficiency problem somewhere..

If it isn't heat or volumetric related, maybe it is the intercooler design as Cory stated.. Maybe there is so much pressure loss across the core that we have to run such high boost #'s to make up the difference.

Take a look at this graph. Keep in mind it is from a MUSTANG dyno which reads lower. A 2001 Corvette (non-Z06) bone stock with a Magnuson added.

400lb/ft of torque right from 2,000RPM - 5,800RPM...

Remember, this is a stock car with stock Magnuson blower.. 6PSI boost for the non-Z06, 5.5PSI boost for a Z06.

This is what I want the E55 torque curve on my car to look like, just at a much higher reading...

stevebez

I agree with the aspect of looking at the area under the torque curve as a good measure of how quick a car is in everyday life - as long as you are not stuck in traffic!

To me there are two issues ...
1) Efficiency in getting the air to expanding in the cylinder.

2) Efficiency in getting air to flow (this gets more complicated when you involve boost). This is really the rate of producing 1).

Ito 1) IAT is very important since the EAT is proportionally stable. If the IAT gets too high the volume by which the air expands (i.e. intake air volume to exhaust air volume ratio) will decline. Only way to improve this efficiency is to get the IAT down - or limit the amount by which it rises over time.

Now think about increasing boost. You are now pumping more hot air into the cylinder to compensate for the reduced ratio between EAT/IAT. Sounds like trouble to me. As peripheral heat soak will soar even further and after a while the ratio would be pretty much back to where you started but with a motor running allot hotter so you might gain a little with higher EAT's - but to me without doubt toy with reliability over the long term.

Increasing efficiency of air flow is tricky in two ways ... firstly increasing effciency increases cooling as hot air is despatched quicker (I think ?? - what you guys reckon) e.g. adding headers and a sports exhaust system. And secondly by doing this though we erode the boost pressure - or do we ... ?

The boost will only be eroded if some of the boost depends on some latent exhaust pressure remaining in the cylinder that has not been able to escape yet... in this case boost will drop off by a small degree by improving exhaust airflow - but in terms of latent internal heat things should be better as well as overall efficiency.

Best mod to me is cool-cool-cool all you can on the intake side. Air boxes, intercooler, IAT, even fuel perhaps ... . Water injectors sounds like a fabulous idea onto the intercooler (or elsewhere - any ideas?)... oversized intercooler, airflow ducting to hot spots etc etc...

Edit: Anyone fitted thermostatically controlled fans to the intercooler? Is there space for this?

Then I would look at exhaust flow efficiency ... if this is really such an improvement over stock only then would I consider upping boost ... but honestly I dont think I will get to the point of upping boost personally.

Would love to hear you feedback - great thread.

Rgds Steve.

04E55 AMG

Victor,

My throttle body from the V12 Bi-Turbo should be installed within the next 30 days and I will take the car and get a min of 3 pulls but more like 5/6 and see how well she holds her power. Based on my conversations with Cory & Brandon during testing of the larger pump, they noticed no power loss after running the same car on a dyno more then 10 times in a row.

Will keep you posted.

vrus

That's great! Can't wait to see it.

The throttle body you are getting.. Is it from the Maybach by any chance? My friend has one in his car on a K3 and I have been trying to drag him to the dyno with me..

Hopefully this week he'll have some time to come out with me and do some runs.

rflow306

Vic were these numbers with stock heads or airflow research heads. Just curious about the customer name listed on the dyno.

Also Cory has stated that a c55 or clk 55 with 6psi has made from 410 to 440 rwhp that's comparable to the c5's with just a bolt on blower. What are your thoughts about this ?

Evolution Marine

Why did the E55, and all the other cars MB used the 55K motor in, end up with an inefficient intercooler system? I think it was the limited space available in all the different engine compartments, and to deal with this MB used the very efficient and compact Lysholm type of Supercharger to help counter the poor intercooler design dictated by the lack of engine compartment room.

Vrus - I looked at the MKB site and I only found front mount intercoolers for some smaller motor E type cars, nothing for the E55. I agree there would be some significant increases there if the intercooler was moved out from under the supercharger. - Bob

vrus

Albert,

Look at the baseline numbers.. 296rwhp is about right for a C5 on a Mustang dyno.. They usually dyno 305 - 311rwhp on a dynojet. AFR heads are good for another 20rwhp - 30rwhp on a stock car.

Yup.. The C55 with 11:1 compression and 6psi boost is doing pretty good at those #'s. I know we have alot more power available to us.. We just need to figure out how to get at it.

I'll give you a good indication if exhaust restriction plays a role once I put on the high flow cats and re-dyno. That should eliminate another possibility.

vrus

This is what I want developed.. I wish the cost was a bit lower.. I would do it in a hearbeat.. Just can't justify spending $15,000 on this when I dont know the gains..

My take on it is that the intake system has been changed to a conical design.. Looks like they have 2 conical boxes (1 on each side of course) running underneath those blue intercooler cores.. I would think they are using something like the BMC carbon airboxes..

medici78

I wonder how much R&D would be involved to tackle a project like that and what price point would be appropriate. Its obvious $15K is too much.

IanSL55

I'm agreeing with this!

~ Ian

vraa

Custom pulley's that are lighter than stock are cheap to manufacture.

The costly part is the R&D which includes numerous trial and error as well as testing with reliability.

Grumpy666

Apologies in advance for the large images to follow. I really wasn't motivated to download, resize, and then upload them to an image server.

It seems that I wasn't very clear on my comments re: the LS1 engine. All comments were meant for the LS1 as it applies to the C5 Vette. I am keenly aware of the other platforms that use variants of this engine, including the ones not listed. I, myself, drive a 1/2 ton GMC truck that uses the 6.0 liter, iron-block version of the LS1.

Victor: - that dyno graph is only meant to sell product, nothing more. Why didn't they start/stop both pulls at the same points? Do you really think it's representative of real life conditions? If the elevated torque reading at lower RPMs is real, it's probably due to the torque converter not locking if it's an automatic. Dunno, but it's not typical. If a dyno operator handed me a plot that looked like that, I would refuse to pay.

Here's a couple of GM-generated dyno plots comparing the LS1/LS2/LS6 engines. The first is data comparing the LS1 (blue) to the new LS2 (red). This is the general shape you should expect to see for these engines.


This next one is very interesting. It shows the LS6 (blue) compared to the LS2 (red). Notice that they make the same peak HP - but look at those torque curves! Which one would you rather drive on the street. It's that area under the curve thing.


Wayne, your blower design statement applies primarily to centrifugal blowers and turbos, which build boost as RPMs rise. Lysholm and Roots blowers will have minimal impact on the torque curve if they are sized appropriately for the engine.

To illustrate this, take a closer look at the Magnussen torque curve and the stock LS6 torque curve in your links above. Except for the step function increase due to the boost, they are virtually identical (be careful with different plot scales). At 3K RPM, the stock engine is at 315 lb-ft and rises to 350 lb-ft at torque peak - an increase of 35 lb-ft. Now look at the Magnussen curve. At 3K RPM, the torque is 440 lb-ft and rises to 470 at torque peak. In increase of 30 lb-ft. Then, both curves taper off starting at 5K RPM and are both down 30 lb-ft at 6K RPM. Almost a perfect overlay. Kudos to your dyno for consistent output.

stevebez:I would really like to respond to your input - I truly would - but I have no clue as to what you were tying to say. Some of you terminology is unfamiliar to me and I just didn't understand most of the rest. Sorry. :o

Now, I'm not saying you guys are wasting your time trying to find large HP increases. I'm just saying that the big bumps you're looking for probably won't appear unless you're willing to dig into the engine. (This statement excludes more boost and bottle feeding.) I think you're quickly approaching a plateau. Making small changes and quickly running to your local dyno is not always indicative of what's going to happen in the real world. The dyno doesn't load your car the same as blasting down the road (although, I think the Mustang dyno tries to simulate these conditions and, hence, generates lower numbers).

After headers, exhaust, IC mod, pulley, H2O injection, ECU, etc, where do you go? One possible suggestion is to drive your car normally for a period of time and then turn on data logging and do a 1/4 mile blast. Analyze the data and see where you're losing power. Repeat after a period of aggressive driving. Temperature seems to be a major issue, yet I haven't seen threads that specifically address it. Is a lower-temperature thermostat or turning the fan on sooner an option? How about small air dams below the bumper area to direct more air flow across the radiators? Better venting of underhood air? Will a bigger radiator fit?

Going to a SLR-style IC is an intriguing idea, but the complex engineering involved and the exhorbinant cost will pretty much relegate this to wet-dream-land.

Sorry for the rambling - just wanted to provide additional food for thought and discussion. Perhaps a new thread that's more focused.

BMWEATR

I've read after only doing the pulley upgrade you will only see about 10 or so seconds of power increase before the hp drops off (below stock)because of heat build up.
this has been talked about on this board way back. doing just the pulley upgrade is a waste of time.

stevebez

Pretty much agreeing with what was said before ... terminology can be a pain sometimes!

Efficiency on the cold side of the unit is what I was trying to get across. I would agree the intercooler seems to be not the best placed unit and this would be the most reliable upgrade in addition to heat-wrapping all the cold points under the bonnet.

Anything that will

1) Reduce or keep down Intake Air Temps (heat wrapping, intercooler mod etc etc)

2) Anything that will improve overall breathing efficiency (headers, free flow exhaust etc)

... have to be the first port of call for any mods ... before you start toying with dialing in more boost in my view.

Rgds Steve.

WayneE

Good point, Grumpy.



2 different dynos and cars But yeah, remarkably consistent. Maybe a good operator is more important than using the same dyno?

jparch

Victor, I would have to agree that the first way to make power is to make the charge-air cooler. I had the same issue with my RX7 running big PSI through an in-efficient intercooler. I then switched to a massive HKS unit and the power gains were unbelievable at much lower boost levels, simply because the charge air was cooler. I have to disagree with you on the "bad design" of the Mercedes intercooler. I feel their concept is the most "efficent" design simply because of the extremely short path from the supercharger to the intake, it simply can't be shorter The key is to make this deisgn more effiecient. I think a good first step is to measure intake temps before and after the intercooler. My brother did this with his WRX before he did any mods. Autometer makes a nice guage with dual needles that gives an accurate reading of how good the intercooler is doing its job. What about using Water Wetter or similar for the fluid??? Also Nitrous Express makes a intercooler spray kit that may work with the frontmount unit, any ideas on this??? Probably the best idea for track use would be to replace the fluid when you get to the track with a water-ice mix!!

vrus

I've seen quite a few Magnacharger graphs and they are pretty similar. Most of them had other modifications, but none-the-less, they were making some good power at relatively low boost.

In my gut I feel that there is alot of power on the table with this car without having to tear into the motor or raise the boost.

In the end, you might be right, and it could all be flow related.. I personally dont think it is.

Kleemann tried to improve on the stock cams in the car. The best they could extract out of those was 10 - 15hp at the crank. Keep in mind, that is using their K2 car as a starting point (higher boost, ECU, headers). This tells me that the cam that is in there is sufficient to produce the power we seek in these motors.

The only other thing could be cylinder heads... But, we know that MKB has achieved 680hp with the stock cylinder heads and using those top-mount intercoolers...

See what I am getting at.. No one has opened up the motor on these cars and achieved anything significant so I have to believe what is there will work to at least the 700hp mark.

The issue that all of them face is that the heat buildup in the motor causes the drop-off in power in the upper RPMs.

I'll answer my own question once the water/meth is installed. If that doesn't have any effect (which I highly doubt) then I will concede that the horsepower plateau on these cars is 640hp without the SLR intercoolers, and 680hp with them.

vrus

Think hard about that now... Flow of air is:

- air enters intake tubes, travels into intake boxes, through filter, into throttle body
- supercharger compresses air, air is sent downward into intercooler
- air travels out of back of intercooler into cast iron tubes which run UPWARD into the intake manifolds
- air travels down the intake manifolds into engine block

It travels quite a bit before it enters the engine. And it is travelling through areas with HIGH HEATSOAK. I dont think there is anything that can be called efficient about the design, other than it is "space efficient" ..

Even Cory @ Kleemann has called it "junk"..

If you really think about it, how much more effort would of been involved in putting air/water intercoolers on the top like MKB did and the SLR did?


Agree 1000% I've been collecting info about various thermocouplers, pyrometers, EGT gauges... I couldnt find the autometer gauge on the website though.. do you know what it is called?

I've put water wetter into engine coolant.. no noticeable changes... I'm using Evans NPG-R race coolant in the supercharger cooling system.. I need the intercooler gauge that tells me temp differentials between in and out to really know how well it is working.

I've looked a the Nitrous Express unit.. Its called the NterCooler. Interesting idea, but I dont want to be filling up 2 containers now.. (water/meth tank and cryo tank)... I might just mount 2 extra jets near the front mount intercooler and use the water injection system to spray it.

medici78

How, exactly, do the MKB and SLR intercoolers work? Is it even the same supercharger?

vrus

They are using the same supercharger. The intercoolers are still air-water intercoolers, but I suspect their volume has increased and they are located ontop of the engine to minimize heat soak and increase efficiency.

E55AMG99

Be careful using water here. Most drag racing sactioning bodies as well as most tracks are now banning this practice after a few nasty crashes. On the street, you might wet the pavement enough to lose traction. Anyone consider chilling the IC water with either a Peltier or using the factory AC system?

medici78

So that would basically be no different than simply adding a larger heat exchanger. Another thing I find interesting is that the Evosport upgrade installs an additional heat exhanger in series. I wonder how is this better than simply replacing the original with a larger/thicker core? I've been doing some research on the Mustang Cobras and they have similar upgrades, but instead of adding additional coolers in series, they jsut replace the original with a much larger unit.

Grumpy666

I second the spraying water/methanol comment. Nitrous would be a better, albeit, much more expensive alternative.

A Peltier cooler would not be practical for this application. To cool the mass, it would have to be very large (which implies expensive), would require a lot of power to operate, and would require a separate cooling system of its own to cool the hot side. We used a small one a few years back trying to overclock the snot out of a Pentium II. It got so hot inside the case we had to connect a water cooler to it to make it work. Certainly not worth the hassle.

Using the factory AC could probably be made to work, but would require some complex engineering. I don't think this would be a practical solution, either.

Vadim @ evosport

medici: There is no room to make thicker heat exchanger, this is one of the reasons we went with an extra core.

Vadim @ evosport

Let me see if I can shed some light on this:

1. First diagrahm shows stock, AMG intercooler. Air (red) enters through air boxes, into 75 mm throttle body, into kompressor. Out through intercooler, than splits into driver and passenger side manifolds.

Note how thick the intercooler is, we measured over 4 psi drop accross. In addition to 90 degree turn right out of kompressor that does not allow air to straigten out as it hits intercooler core.

In addition, the intercooler sits right between the cylinder, which causes a lot of heat soak.

2. This is a picture of SLR's engine. Note the intercoolers are now on the side and air inlet is in the middle. Note how big the inlet air box is, this is probably biggest production air filter.

Second picture shows what SLR intercooler looks like by itself.