I just got back from a 30 mile trip - A major accident on the freeway and I was in stop and go traffic most of the way home. Outside temp was 65F ( I luv CA) - needless to say the engine was at, or slightly above normal operating temperatures.

I parked, got out and felt the hood - very warm in the middle and very cool towards the "wing" - big temperature difference.

I popped the hood and felt the top of the airbox and it was warm but not so much that I couldn't keep my hand on it. The intake tubes were warm but not hot so I removed one and felt the air filter - very cool to the touch. The Y-Pipe hoses were barely warm and the Y-Pipe itself was very cool to the touch.

The top of the plenum cover where the SRT6 logo is was very hot as was the metal Y-Pipe (w/MAS) that feeds the intake manifold (very hot). The overflow tank was also very hot.

While this is not shocking or new, it confirms to me that intake air is not really "heating up" prior to the SC and the airbox and the filters were not "cooking", that's for sure.

Engine heat soak that is happening after the SC and the SC compression itself are the main contributors to rising intake air temps.

Makes me a believer in a bigger HE in front, Johnson pump, separate overflow tanks and the EVOSport phenolic spacer kit.

 

Someone on this thread had said that with the OEM set up that the air filters would be cooking or hot, and I made the comment that with as much air moving through them it should help cool them down.

 

The ends of my tube's are now 2&1/4 inch ID, there are some pic's in a thread titled opening up the bottle neck in the mod & tech part of the forum. Look at the difference in this pic, the peice on top was where the air came in, rounded out it was only about 1&3/4 inches.

 

Steve,

You know I prefer the look of the stock setup. However, I've been leaning towards the Needswings strictly for power.

I am still thinking about how to make an intake that will use both sides, run THROUGH the air boxes, and put the filters out front.

If you cut a hole in the back of the air boxes, you could feed a tube straight through it and straight out the front keeping the stock cover and stock boxes for aesthetics only.

Maybe I'll mess with it one day.

SQ

 

Your last post makes me think it would turn out to be More of a hack job than anything else I have heard posted here. Custom bending and welding intake pipes or buying after market parts are going to be much cleaner looking than hacking a hole in the air boxes. there are so many problems wit doing that I am not going to take the time to lit them. Remove by after market or make your own, don't hack holes and hope it looks good.


leadfoot

drive forward, race backward, and always keep the rubber side down!!!!!

 

If I am someone who is concerned with aesthetics, would I do a 'hack job'? Think about it!

Not likely...

Do you know what I am and am not capable of?
No, you don't.



The most difficult part is the tight bends that will be required near the back of the air boxes. This probably wont allow 3" tubing due to the radius required. However, if you have two pipes instead of one, you should still make power. Then, your next concern is turbulence at the Y.

 

Shawn -

Don't let ANYONE tell you what you can or cannot do. (but you already know that) No one has the market cornered on ideas and designs.

Here is a great website that can help you out and provide killer parts at reasonable prices.

http://www.spectreperformance.com/#HOME

Good luck with your projects

 

you can order Spectre stuff through Jegs with free 1-2 day shipping. My rubber 90 should be here by next weekend, delayed because it was backordered.

 

That link looks pretty useful, thanks!

Good info SRTpowa.

I mainly just need to get under the hood and see what all it would take.

The main problem right now is that I've lost access to the TIG I was using, so I am limited to MIG only. MIG and Alum don't mix well...it can be done, but it isn't nearly as nice. Because of this, I haven't been really motivated. With the recent rain, and now the trans leak...it may be a while before I attempt anything.

SQ

 

I think what needs to be addressed is how much air flow is actually needed. It's a 3.2L which is about 192 cubic inches. A v6 configuration so you are feeding 96 cubic inches per side. Hell it is basically the size of two motorcycle engines. How much draw as far as CFM can it take at maximum. Needswings intake is a 3" tube and more then satisfies cfm rating even with a pulley set-up. So technically two 1 1/2" straight flow tubes should suffice. Since the run obviously isn't perfectly straight and has some bends a 2 1/2" tube on each side should be more then adequate. I think an SL55 Y pipe and tubes with left and right side tubes would be more then enough. My indian which is a worked powerplus 100 has 120 RWHP running a tear drop air filter which has a pretty small surface area but definitely flows enough air, granted it is mounted on the neck of the carb but still the surface area isn't great. Somebody come up wth maximum CFM the engine can suck and then the maximum air flow you can pull through two 2" tubes with some bends, and we'll take it from there

 

I think the size of the engine would be a valid limiting factor if this weren't forced aspiration. With a supercharger, you are compressing the air in...its not just what can be pulled in from the piston being pulled down to the bottom of its stroke. Compression ratio of our engines while not under boost is not at all the same as it is under boost. I think the limiting factor is not the size of the displacement...but how much pressure our engines can withstand before blowing a head gasket, et. al.

If I remember right, the estimated limit of boost on the 2003-04 cobras was 27psi. At that point, you were risking blowing things out from the pressure inside the engine. It came from the factory with 8psi and a compression ration of 8.5:1. That's a hell of a lot of room to increase air intake, and make more power. I think I remember a calcuation by Powersurge performance on his lightning that at 21psi on the supercharger, and a 150shot of nitrous, the effective compression ratio in the cylinders was 45:1.

Our stock compression ratio without boost is 9:1...Our superchargers are set to 14.5 psi of boost stock, aren't they? We are already pushing WAY more pressure than the cobras were stock, at 8psi of boost into 8.5:1 compression ratio.

I think what we need, is the cfm of draw the supercharger is capable of at the RPM it turns with stock and various aftermarket pulleys. I wouldn't be suprised to see 1150 cfm being pulled by an aftermarket pulley setup with high high boost levels, IF the air intake is large enough to support that flow.

Anyone know exactly which model our cars use? http://www.opcon.se/index.asp?sPage=1&langID=1&cID=14

 

Here's an article I found:

Unlike the Roots-type Eaton blower used on the supercharged Mercedes four cylinder engines, the 260kW engine uses a very sophisticated Lysholm-type supercharger produced by IHI in Japan. Driven at 3.3 times crankshaft speed, the helical lobe supercharger develops up to 1 Bar (14.5 psi) of boost. One of its two cast aluminium rotors is Teflon-coated (it's the yellow one), and the supercharger drive is through an air-conditioning style electromagnetic clutch. Despite the high efficiency of this design of supercharger, the blower still requires 45kW to power it when the engine is at its 6220 max rpm. Of course, the blower is also then flowing a lot of air - up to 1200kg per hour of it, in fact.
In order that the supercharger could be fitted into the already tight confines of the SLK and C-class bodies, it has been mounted within the 'V' of the V6. Sandwiched between the supercharger and the inlet manifold is a reverse-flow heat exchanger for a water/air intercooling system. Aimed specifically at reducing temperature peaks (an area where Mercedes-AMG engineers believe that an air/air system can be less effective), the system has its own radiator and electric water pump. The complete supercharger and intercooler system adds only 25kg of mass - so the power/weight ratios of the two cars equipped with the upgraded drivetrain are radically improved!

The supercharger engages only as required; when it is not being driven, the intake air flows through its rotors (ie no external bypass is fitted). Supercharger operation is dictated by the Bosch ME 2.8.1 engine management system on the basis of engine speed and load. However, the supercharger, which is driven from the engine's serpentine belt, will not engage at engine speeds over 3000 rpm - if this occurred, the belt stresses would be too high. If required, the engine can develop 400Nm from 2300 rpm to 6100 rpm.
The better breathing and engagement-on-demand characteristics of the supercharger have not turned the engine into a polluting and thirsty monster. Mercedes-AMG engineers are proud that that the C 32 AMG has a NEDC combined fuel consumption of just 11.5 litres/100 km and already complies with the EU 4 emissions standard that does not come into effect until 2005.

Anyone know how to convert 1200kg/h to cfm?

 

Atom,
My duramax diesel makes 30psi of boost under load. It is a 6.6l turbo diesel. Inlet to the engine turbo is 4" in diameter it has been proven on that truck, that the factory intake is as good as it gets. The duramax has more displacement makes more boost and spins that turbo a hell of alot faster then the supercharger could ever dream of and a 4" diameter intake is all that is needed. I dont think the 3.2l engines moves that much air. Yea the supercharger compresses the air and increases boost, but you still have a throttle body which is a fixed size that will only allow so much air flow.

 

If my conversion calculation is correct (and I wouldn't bank on that by any stretch) our stock supercharger setup will pull 706cfm if there is no restriction in the air path like a small intake tube. My cobra was pulling 1100cfm if I remember correctly, and that was through a 4" diameter JLT cold air intake. Needswings just posted that their 3" intake will flow 900cfm so that sounds about right to me...that would give us about 200cfm above what the stock supercharger can pull.

If the ASP kit increases the rpm of the supercharger by 14%, does that also increase airflow by 14%? If so we'd be pulling 804cfm with the ASP kit. Still well within the limits of the 900cfm air intake.

Clearly the stock intake system does not flow anywhere near 706cfm, if we are getting a 25-30hp increase by removing that as a restriction path. The next question would be, is the SL55 air intake setup capable of flowing the 804cfm required by the ASP pulley setup?

If you go up to the LET pulley you would be needing 850cfm. Still within the range of the Needswings intake...but the SL55 setup?

 

When I done the SL55 hose's &"Y" , I measured the stock air box to the "Y" and it was about 2&1/4 ID. I took my car out to test it to see what kind of gains the SL55 set up made and it gained me 0.3 to 0.4 seconds & 3 to 4 MPH in the 1/4. I was very pleased and thought now I need to make the ends of the intake tube's bigger where they go through the radiator support. I wanted to make them at least 2&1/4 ID because I knew that's what the air boxes were, (pic a few posts ago). I took the car out to test it out expecting to see at least 0.2 seconds & 1 or 2 more MPH in the 1/4, but it made no difference. I think after the SL55 mod, it's getting all the air it wants.

 

It sounds like, if you have two tubes at 2.5 inches each...that's flowing more than the supercharger is pulling (804cfm) with the renntech pulleys. In that case, no modifications to your airpath is going to give you any further gains. The only things we can be SURE of, is that the stock air intake flows less than 706cfm, and both the SL55 intake and Needswings intake flows more than 804cfm, hence the gains.

 

Atom that was AWSOME I was just about to start doing conversions to cfm but you beat me to it

 

Someone give that man a beer...

 

A nice belgian golden ale......None of that cheap shhhhyt!

 

Absolutely....hops are your friend!