OK. I have a 2002 SLK32 AMG with about 76k miles. Mods are few but they are potent. Rob's NW DCAI, Eurocharged 65mm pulley and tune. These likely added 50hp, not whp but 50hp. I am considering Rob's tweaked Intakes and the ported lower "Y". However in speaking and reading it seems the return on what would cost $750. is 15whp at best with another tune. I do not have a wideband yet and these email tunes seem risky.
Then there is the $799. downpipes. I understand with cutouts they will knock off .3 but I don't want a loud, poor idling motor. Given these mods and say having another $1000. to spend what would YOU do?! I am planning on a set of TOYO PROXES R888's for the rear at least and they are a road race DOT legal tire, they will stick as long as the motor does not bog they should help but it is motor work to consider, maybe just a good oil change and plugs/wires could deduct a tenth. Thanks for opinions.

 

Wavetrak rear end.

 

I can hook with a set of tires. Planning on TOYO PROXES R888's. No really great power for the buck now is there?

 

No power at all for the buck, just getting it to the street/track.
I personally don't have a dog in this hunt, it's just that the wavetrak is considered indispensable by the 1/4 miler SRT6 guys.

 

As I understand it - power to the black top through 2 rear tires (wavetrac) is better than 1 (stock)

 

I installed a pair of Rob's cat delete ss downpipes (without cutouts) on my SSB SRT6 roadster and I like the improved sound and slightly improved performance. Not cheap and a difficult install if you have to crawl around under the car up on jack stands (I don't have a hoist but am now considering one). If I do get a hoist I will probably do the cat delete downpipes for the black SRT6 roadster too as I like them that much.

 

The tweeked manifolds will give you as much as 80 ft lbs of additional torque between 1700 and 2500 rpm. Amazing but true. It wil give you an extra 10 or 15 whp at redline all dependent on getting a custom remote dyno based tune. These were my results. In addition, the car acquired a much more deep throated satisfying growl in the low to mid rpms. I have a stock exhaust. All that said, sooner or later you'll want the wavetrac.

 

You already know my numbers. Everyones will be different as you've seen. If it was my car/decision I'd go with the manifolds and E/C retune. E/C has done enough of them to get close enough to be safe without a wide band. Both the downpipes and manifolds are proven. The wavetrac was big for me. It took me from 13 to 12 as I never learned to hook up with street tires and open diff. My car will spin the rear tires with the wavetrac going wide open throttle in 2nd. so you can understand why it's recommended. Choose the mod you can afford as the one's being considered by you are all worth while.

Les

 

I have yet to install my big manis or heat exchanger(been waiting to replace my catch can), so I can't say what improvement they may add. If I had a grand to throw at the car it would most likely be spent on some MT ET Street tires and a set of the lightweight Tolimann wheels that used to be on the CLKs. 13 pounds per wheel. The WaveTrac is $1,295 and I would totally have the 3.27 gears installed along with the appropriate TCU tune...another chunk of change. For what it's worth in the 1/4, practice is the best thing to make the times drop. All of my runs have been on summer street tires and I think I've done pretty d@mn good with that.

 

181 pulley, tune and drag radials. add a 75 to 125 shot of nitrous and run faster than any 3.2 mercedes motor out there. you will be chasing amx with these mods. everything else save the wavetrac is a waste of money . been there tried them all

 

I disagree with Steve. The wavetrac was my favortite mod. Made the car handle so much better out of the hole. You can have all the power you want, but if it doesn't handle well, it isn't as much fun....especially spinning one wheel.... Not a fan of nitrous. Never will be, hp or not, times or not. I would look at manis and tune and save for a wavetrac.... 3.27 and TCU would be nice, but it would be my last mod.....good luck...

 

If you gained that much torque at those rpm's it still must have been decently high at say 3500-4000rpm, maybe half? I'd take the torque as that's what moves the car, especially on the street, just seems awfully high, 80lbs./ft.? That's for the $599. intakes? Got a copy of the pull?

 

torque before after.jpg

here's the final pull after tune. I have all the mods you have I think, plus the tweaked manifolds...so the before is everything BUT the tweaked manifolds, and the after is WITH the tweaked manis. You can see that they make quite a huge difference at the low end, but that by mid-range, they don't help all that much. At 2500 RPM, the before torque was 170.50 ft lbs, and after tuning for just the new manifolds torque was over 298 ft lbs. I hate shifting gears, so all that low end torque is awesome fun and sounds awesomely mean

The shop owner (peter@ispracing.com) stated that his dynojet consistently reads 10% below other dynojets by the way...so I take him at his word since he has nothing to gain by admitting that. The previous max whp w/all mods in my sig but prior to the tweaked manis/tune showed 340 whp, so taking him at his word that his dyno reads 10% low, that'd put the whp with the tweaked manifold/tune at least in the 365-375 whp range if it were run on the previous dyno.

I would go back to the old dyno to get apples to apples testing if I could, but that dyno has been replaced at the original shop, so there's no going home - sure wish I could though.

 

tweaked mains before after2.jpg

Here's a variation of the first chart, taken from the same run. When I spoke to Rob at Needswings, he let me know I should expect most of the gains at the low (especially) and mid range, and that's exactly where I wanted it. The reason the dyno chart starts so low in RPM is because I specifically asked for it that way so I could document the mani/tune's effects on the low/mid end. Essentially, it totally frees up the supercharger intake so the supercharger gets to work at least 1,000 RPM earlier in the rpm range.

The previous dyno charts measured/run on another dynojet at another shop, prior to the installation of the tweaked manifolds showed a peak whp of 340 and 339 lb ft of torque. This chart shows 340 whp and 327 tq, so the shop owner said to add 10% to his/this chart to gauge the effect of the new manis/tune. Numbers notwithstanding, it is extremely clear that there is tons of new torque at the low end, and I can break tire traction anytime now even with wavetrac installed and newish 285/35/19 Kumho Ecstas XS autocross tires with DOT 140 compound rating on the rear.

 

Well, I was starting to doubt my choice to do the intakes and lower "Y" but you have convinced me. Not a huge gain for $750., would like to try the sheetmetal intakes but $1500. is nuts and even though I'm nuts a lot of the time I don't think so Jerry can do the tune difference for these intakes in an email?
Some cooling and maybe a little exhaust work is about it. Why is a tune needed for changing to 3.27 gears? That's like going to a tire that is about 1.25" shorter than stock, same thing?
I am looking at stations selling 100 octane for a separate tune to see what he could do with that level of fuel. I used to run 25psi with a big turbo on an Eagle Talon with 112 leaded, crazy quick. Mark

 

So you are getting email tunes from Jerry and just using the dyno for numbers?

 

I understand the posi deal but most of what I do is on a roll. I'm not healthy enough to spend a few hours at a track, several back surgeries, one more pending. A 12.25 at 115mph would be my target. The guy back home running the TOYO PROXES R888's runs 10's with 1.6 60' times on these tires. He's also taken the car, '93 Mazda RX-LS motored ride to 185, he's looking for a 200mph ride! Crazy.
Thanks again for helping me decide to stay with the tweaked intakes, I'd love to get a stronger bottom end, then wavetrac

 

No, the tuning is done in real time on the dyno...this is NOT a canned tune. If you want this custom tuning done (and you should), ask Jerry for the closest-to-you Eurocharged affiliated shop and arrange for the shop to have Jerry remote tune the car on the shop's dyno.

 

That's a good goal and still keeping the car fun and not too edgy.