I installed the SL55 setup about a week ago (THANKS BB) and finally got to the track. This was my third trip to the track and as a rule I limit myself to three passes. My second track visit was stock and my personal best was 8.6xx (looking for time slip) but averaged 8.7xx. You can find my first track visit under the My first time…Let herrr RIP…I think? thread with stock numbers. Anyway, made my usual three passes and called it a day/night, leaving with mixed reviews about the SL55 setup.


First run
60'- 2.048
1/8- 8.610
Trap- 82

Second run
60'- 2.05x
1/8- 8.64x
Trap- 81

Third run
60'- N/A
1/8- 8.68x
Trap- N/A (left with out time slip)

As you can see with the SL55 setup I managed to stay in the 8.6 ranges. I would be REALLY excited about that, if I didn’t run an 8.6xx stock. I did not have any slippage issues with the SL55 but had major problems running stock. One could say track preparation caused that issue but I’m going to say this.

• The SL55 setup robs the car of low-end power (minimizing slipping) but attempts to make up “lost time” in the higher RPM.
• I know heat soak is an issue for our cars. So, IMO the larger air boxes means increased air temps, which contributes to the problem (based on progressively worse numbers).

I will head back to the track on Thursday for my second run with the SL55 setup, to obtain a base line prior to pulley install. Expecting at least an 8.5xx with this setup .

Edit- slip numbers were bundled.

 

Did you by chance do a throttle reset so the car can re-learn with the new intake. I'm thinking about getting a Spring Booster to pair up with a new intake so power comes a little sooner rather than trying to make up lost time.

idk, it's a suggestion

 

What does making only 3 runs prove besides OCD? Are you trying to decide whether or not to keep this intake? Fluid dynamics will prove that the SL55 will outflow the factory intake, but probably not as well as something like the NeedsWings. With all the variables in drag racing, (weather, your driving, heat soak, traction...etc) you haven't made enough runs to establish a reliable base line for which to compare the two intakes. My suggestion is return to the track, and bring a weather recording device for collecting Density Altitude and Outside air temperature at a minimum for each run. If you have something monitoring your engine intake temp that is worth recording as well. Your driving has to be the same everytime to remove that variable, also an 1/8 mile track might not offer enough information, hopefully you have a 1/4 mile track handy. Or you could just make a safe assumption that the SL55 intake does perform better, throw a bag of ice on the blower between runs and have fun until your pulley arrives.

 

I asked Rob of Needswings if he would be going to the private Midwest Drags with all the other SRT-6's on the 12th.

I figured it would be a great opportunity for him to bring an extra intake and allow others to compare the NW with whatever setup they are running for a few runs. Members have said it's an easy install so I figured it could be done between runs without much trouble. It could end up being great info for all of us because it would eliminate the "Different dynos - different cars - different days" senerio. Plus we could see how his car - with all his mods - ran against the others on the same track / same day.....

As for heat soak caused by the airboxes - I installed an IAT gauge and Hi temps are more of a problem when at a stop and no air flow around the HE. Once moving - air temps are actually pretty low - until you boost - and this is with the car at full temp.

Here is a test for you - run your car to full temp - hot has you can - open the hood - pull one of the intake tubes, feel the air filter with your finger - there ain't no better test.

Here is a pick of my IAT's @ 100MPH and boosting.

 

Unless you are running a bigger pulley I don't think the SL55 "Y" will gain you that much. The 3.2 OEM "Y" should be more than enough for what the stock pulley can feed the S/C.

 

I will be a tthe drags Saturday and if anyone wants to try its easy as hell to swap and install the needswings intake.

 

GatorLCA-
I will try the throttle reset because I didn’t do that .

Parawxman-
Two track visits, three runs each, gets me six runs for a baseline on any mod and I think that is good enough. Not trying to decide if I like the complete SL55 setup, just not seeing what everyone has described (noticeable gains). I’m aware of all the variables and it’s not that serious for me to test all those variables. I think a 1/8 track is sufficient to measure performance. If it’s good for hot rods to test on, I’m thinking its good for a street legal car. I am lucky to have a ¼ track near by as well and will visit it once I “know ” what my car can do. Thanks for the ice suggestion; I will use that tactic on Thursday.

BB-
Hopefully Rob can come through with that test b/c it would be useful information and eliminate those variables.

Let me clarify the air box contributing to heat soak maybe I have the wrong term. I don’t know what the temp is/ would be on the stock setup. I have to believe that these larger SL55 air boxes heat more air (run hotter than stock), which is a bad thing, right? I’m wondering what temp the stock air/ air boxes are/ would be compared to the SL55 setup.

Steve-
I’m running the complete SL55 setup. I would hope the stock pulley could feed more air to the s/c if air follow area were increased.

 

Gang -
I discovered my SRT was set to run way to rich from the factory - perhaps that's why I noticed such a huge change when I installed the SL55 intake. Perhaps your ECU is set to run leaner - Just a thought.

The SL55 intake allows for plenty of intake air flow for the MB V8 SuperCharged engines - I have no doubt it delivers for the SRT.

The weak point in any intake is the choke points. Unless there are radical bends in the system the restrictions will always be in the air filter. As we know - the SRT factory intake has choke points at the Y-pipe, the radiator support (you can hold these in your hands and see). The SL55 airboxes has bigger in-and-out openings and more space between the (larger) filters and the bottom of the boxes allowing for more airflow. I calculated this ratio to be around 25%.

Neither my stock or the SL55 Airboxes would ever get so hot that I couldn't place my hand on them and keep them there. I don't know why a bigger box would matter. Temp probes are made small to heat sooner- heat sinks are made large to heat slower....

I do know from testing with my IAT gauge that IAT's on the SRT6 rise quickly when you are at a stand still. I think Steve's fan mod is probably the best mod for the hard core drag enthusiast. I'll bet he drops his IAT's by 20-30 deg. while staging. I did notice that it took a little more time for the IAT's to cool once moving again. I'm sure it takes the coolant time to dissipate the heat - this is why a better pump and larger HE will also help (especially for circuit racers)

I wish luck and suggest you get your ECU tuned. Perhaps put it on a dyno with a A/F probe to see where your at. If you going to chase 1/4 mile times - your going to have to tweek a lot variables.

 

In hopes to impart some of my past experience to your testing scenario...My drag racing experience goes back 20 years on numerous blown cars. Regarding 3 runs per mod...if you are talking about a NA, 17 second car not prone to wide variations in performance due to temperature, traction and driver, than 3 runs is adequate...On a fast car like this, there are too many variables effecting the outcome. With my SRT6, my last three runs, over a 2 hour period varied from 13.4 to 12.9, with the only variances being the weather and the driver.

Regarding a full 1/4, a truer image of HP vs Torque can be seen if using the rest of the track, that is where a less restrictive air intake will begin to be more noticable. Often times the hotrods testing at a 1/8 mile are merely testing the "launch" to see if the suspension will hook up or to practice their "trees" or to gauge the performance within that narrow parameter. Learning to launch your car and the ins and outs of the track are a good idea on the 1/8, it makes getting more practice in easier.

Although I advocate icing on the blower between runs, it will only skew your results for the purposes you are investigating now; the car will run faster with an iced blower. Also, I'd watch that the ice doesn't start draining under the car, leaving it in the bag helps. The track officials won't let you run if they see fluid dripping out at the line. Another thing to try is run the heat on high power with the windows open, closing windows just before you pull to the line. I shut the heat off when staging. Good luck

 

I could be wrong, but I would really think when they designed the engine & air intake system that the OEM 3.2 "Y" would be more than sufficient enough to supply the demand of air to the super charger with just the OEM pulley.

 

I would not want to take anything away from what you've said, but my own
experience after installing the SL55 intake is that my motor has really
come alive. It seems far more powerful on the low end and upper ends
of the power band. Of course this is all my perception, and that could
be mistaken.

Coyote

 

Subscribing... I put mine on (full SL intake) this weekend.

Can't imagine it having no (let alone an adverse) effect...

 

ECU tune- Fact.
MB V8 air flow- Fact.
Choke points- Fact.

Heat- Matter of Opinion. The threshold for heat or pain or discomfort differs from person to person. Bigger boxes equates to more heat retention that equates to air being less dense. I think if aftermarket intakes try to reduce or minimize heat then heating is an issue (however big or small) with all intake systems, faulty logic?

Stand still- Fact. I notice every time I’m in traffic the car runs hotter. A better pump, larger HE and Steve’s fans would do wonders no doubt . However, once IAT raise it does take a while for them to return too normal (as you stated). Do the larger boxes contribute?

¼ times- Fiction. I’m not chasing times just “attempting” to gauge what mods equates to in track numbers. There has to be a baseline number attached to the SL55 setup just as there is one attached to the stock setup and other aftermarket intakes. No one has provided that documentation with only the SL55 mod ( ). I think I will get the car dyno with SL55 setup, switch back to the stock setup and see what we are working with. That will happen after my second trip to the track with my SL55 setup.


: Attention:
This thread is none violent and none cynical, all thoughts are welcome .

 

Do the dyno, i think youll see the results will show you an improvement with the SL55 intake.

And if the larger airboxes reduce low end power so do larger intake manifolds/supercharger housings/etc, based on your same logic.

 

I’m not saying larger air boxes reduce low-end power. What I’m saying is the larger air boxes are more susceptible to heat which contributes to heat soak/ increased IAT (we know what that does). I’m sure the SL55 setup will provide gains but how much (dyno here I come)? It does something because my track numbers were consistent all three runs with it. I launched the same, ran in the same lane, waited between runs about the same amount of time. As you can see my numbers became progressively worse (still decent). Why For now I’m going to say what looks obvious, larger heating area helped contribute to heat soak/ increased IAT. My observation is no different from a butt dyno .

 

It is sufficient enough to provide the level of power they intended to be able to claim and still keep it stupidly quiet for all the people the complain about "engine noises". Very few; if any, OEM manufacturers will equip a car with parts that will run 100% efficient. Higher HP= higher insurance..............higher airflow=more noises to be heard..........and so on.

 

Visited the track yesterday with SL55 still in-tack and on my first run I pulled off a personal best 8.56 . Making four passes (you will understand) instead of three I managed an 11.28 (understand), an 8.63 and an 8.65. Minus the 11.28 (launching at 2000 rpm SRT6 no likie on street tires ), I was the third fast STREET CAR running that night. Honors go to a moded Evo (8.1x) and my buddies moded Cobra (8.1x) ran first / second with my moded SRT6 bringing up the rear . I spoke briefly with a tuner about two dyno runs, one A/F and a possible tune on April 23.

GatorLCA- Throttle reset done.
Parawxman- No ice you are correct.

 

Nice work - Nice runs -

From my experience - Get your pulley installed and then a tune - and you'll be grinning from ear to ear....

 

i grinn anyway, i'm still stock, i ate up a newer 911 the other night red light to red light
at least 3 to 4 cars the dude gave me a thumb's up as he turned away lol

 

He must have dozed off at the red light. just kidding.