i think bench racers don't know squat about building these motors. i ran 65 and 178 stacked with 550 looped rail tuned and ran 11's and was in full street trim and drove the car on the street with zero issues.

having said that if you want to run 11's all thats needed is d/r slicks, a 181 pulley a single cai and a competent tune. 11's all day

 

JR, I have read this thread and especially your post, many times. Exactly what were you trying to achieve? It took me nearly a year to get to where I was satisified with my stacked pulleys, 178/70. I started with a 65mm SC pulley and loved it. As you recall I bought th 178mm crank pulley from you. Research shoiwed the SC we have does not like to rev beyond 15,000rpm when dividing the crank diameter by the SC pulley diameter multiplied by the max engine RPM. Of course the SC rollers spin up to 3 times that of the number we get doing the math.
This is when I looked at Jefasolds 70mm sC pulley. Jim had that nailed a little past the 15,000rpm number but not crazy like doing a 178/65 combo which yields 16,978RPM at our motors 6200rpm redline. Trying to do that combo creates a lot of work with questionable gains.
JR, I agree with you that the car should be done in a manner that makes driving it a pleasure and not a call to AAA!
If you are trying to run a 178mm crank pulley or larger AND A 65MM SC pulley the fun is gone in place of frequent AAA calls! I have only addressed the stacked pulleys here but there are bother mods that do not return much on the dollar. Exhaust is one and once again Jim has a good idea with a "Y" pipe and a large single pipe to keep the unbalanced exhaust pulses from slowing the car. I am going with a combo of a Magnaflow TRU X-pipe internal with a "Y" pipe after the X-pipe muffler leading into a large 3" pipe back to a 3" in/out Borla to complete the system. Still room for Rob's log headers should they come about. After a year I have few mods at all but the returns have been good due to research and asking questions from guys like Tim who have been there and done that!

 

So you also learned that stacked pulleys are not needed to run 11's. Neither is a DCAI. Just ba 181mm crank pulley and a single CAI with a c:competent" tune. Let's call that a DYNO tune as Jerry will do rermote tunes if anyone finds a DYNO operator willing to spend 2 hours doing pulls. My question to you is what did the DCAI and stacked pulleys and fuel mods gain over the simple mods you list, a few tenths? For me it is torque, passing semi's easily and that feeling of being pushed into the seat that torque provides.

 

I think I mentioned before - the SC has an internal gearing which spins the right hand side 5 lobe rotor to 5/3=1.666 times the pulley rpm. The left hand 3 lobe rotor spins at the pulley speed.


I've toyed with the idea of putting the larger capacity (longer) SL55 SC on there to negate some efficiency/heat/AIT issues. A guys done it on the 3.7L M112 motor.....maybe one day - it would probably be coupled with integrated 2ndry cooling tanks/manifolds and maybe the Killer chiller - well that's the current thinking/dreaming. At the end of the day it all takes time and money.....alternatively E85 would be a game changer - others opt for N2O

 

Lots of great info , im new here have a 2002 Slk32 new to the platform as well
Car
Currently has No tune
Running needswings DCAI , Supercooler, catch can, 178 crank and pulleysaver kit , updated ic pump and isolation kit , running ngk laser iridium stock heat range and magnacore wires nothing major just some bolt ons but

Im currently installing a zex wet kit 75-125 shot pretty complete setup bottle warmer, window switch, remote opener, purge kit, etc etc as well as 550cc injectors and the 68mm fixed blower pulley im getting a baseline tune from eurocharged so they can dynotune it from what i see its safe to stay on the lower side of RPMs? I know some increase the limiters to 6500 but would it be better to stick to the stock limiters ? Also whats the limit of the stock fuel pump i was advised to wait on changing it i would have more peace of mind with at least a 255 walbro
Waiting to see how it goes ill be running a larfer fuel jet to help add extra fuel at high rpm/boost and will mix a few gallons of race fuel when i spray it



Here are some pics ,
https://instagram.com/p/9fKa1nNFOT/

https://instagram.com/p/8g8LC3NFF5/

https://instagram.com/p/8fYJJBtFGa/

https://instagram.com/p/8teD-SNFFs/

https://instagram.com/p/9VLK8cNFEH/

https://instagram.com/p/9YuRlAtFOH/

https://instagram.com/p/9aGpVKNFEK/

 

The engine will continue to make power if you rev it to 6500 rpm or higher. The problem is with the TCU. The rev's climb so fast you need a large gap between the ECU limiter and TCU shift points. If not you hit the ECU limiter. My ECU has the limiter set at 6500. My TCU WAS set at 6400 and I hit the ECU limiter every single time in every single gear. I went back to the stock shift points in the TCU and I still hit the limiter occasionally during the 2nd to 3rd shift. Perhaps because of changing the diff to a 3:27. In other words, to shift at 6400 you'll need the ECU set real high. Based on the way my car acted and unless someone is doing it better now, I'd say 7000. Since your getting a dyno tune from E/C you should talk to them about what's possible with the TCU. I've never used nitrous so I won't give my uneducated opinion. BTW, on a Mustang dyno, my car made 20 hp more at 6400 than 6100 with similar mods as yours. (stock injectors and Pierburg fuel pump)

Les

 

Got cha , i will be keeping the stock Gearing for a while unless the rear takes a dump on me . The only concern for me is revving to 7k with stacked pulleys will put the blower a bit high past the efficiency range of it wouldnt it ? . So id stay withing about 6500 on the ecu thats if my fuel can support it
So maybe if i set the shifts around stock and make the ecu limiter at 6500 it may work well? For sure i will ask Eurocharged on that i plan to retain stock gearing because traction may become an issue with the nitrous and i will spray in 2nd gear to begin with and see how things go

About how much did you put down with the similar set up , im at sea level and saw 19.5psi on the 178 crank alone
Logged through the ecu sensors
I need to ditch the catz and replace resonator and muffler to let it breathe
I saw the 75 shot gave a guy 100rwhp/100rwtq on another car with a bit less mods put down ~400/400

 

Rod, please don't lump all of us with stacked pulleys in together. I know my car will do 160mph, been there chasing a 400HO Camaro SS, dead tie but that was before i had the larger injectors and matched pulleys. Yes, it can get frustrating, I tried 2 sets of used Bosch injectors before buying a set of new 550's for only $225. Look at my mods. It took me a year to do them. Not because I could not afford them but because I need to do research so I know that they have a better than average chance to work.
I agree, do whatever mods you or another want and get out and enjoy a unique car!

 

Austin, go back and read the post I had just before yours. Stacking a 65 SC pulley with a 178,181 or a 185 crank pullEY. Our IHI LYSHOLM superchargers were not designed to spin that high and be efficient and that des not take into account the heat that sort of stack creates!

 

After applying the the equation- Crank÷SC×6200, ive determine that maybe you should of only took your SC pulley machined down to 73mm. Yes i know only 1mm (.039) difference but that 1mm is 648 rpms different. 178÷70×6200=15,765 if you only took the SC down to 73, your numbers would be 178÷73×6200= 15,117. The 73mm may be the route i end up going. A 181÷74×6200 is just above that at 15,184. I wish we could get into more custom crank pulley sizes. That would make fine tuning much better.

 

That's a good idea, if someone could come up with a pulley that had a spline that you could just slip a different size pulley onto it. Interchangeable sizes and just a few minutes to change. Maybe this would lead somewhere. I don't know if my machinist friend could or would want to give it a try but there could be pulleys from 74 (stock) all the way down to 62 or so.

 

I was with ya all the way till u said 174 (stock) not sure if that was a typo or....? I wonder if we could have a 178mm crank pulley machined down to a 175mm and run that with a 72mm SC pulley and that puts you at 15,069 rpms.

 

Rod, what are you trying to achieve as you are just about splitting hairs. The difference between 14,784 and 15,117 is 2.25%. 14,784 is the 155/65 combo which is around 17psi? I'll call it 18. 2.25% of that is about a .4 psi increase. You seem to want to be right around 15,000, right? Any reason?
You know my combo, 178/70. The usual fuel mods and a set of Bosch 550cc inj's. My biggest obstacle was getting a tune for the 550cc inj's. I ended up using a tune for 450cc inj's that had extra timing for when I ran TORCO. I used the adjustable regulator from there to get healthy AFR's. It is running great. For me the reason for more options would be to get the boost even quicker for that great low/mid range torque. I have not sat down to see what could be done with the existing 178/181 and the 185mm crank pulleys as we know the SC pulley can be custom sized. I think my 178/70 combo is near the top. Jim runs a 181/70 which yields 16,031. Call that the max as our SC is not efficient and begins to push hot air. Whatever your goal is can be achieved with some "adjustments" to the tune. Mark

 

Definitely a typo! That or I was delirious from Penn States' win over Illinois. I'll be more precise in the future. That would be on big SC pulley! LOL

 

I think that some of the differences that show up in our individual cars can be related to the differences in temp and air density in our respective regions. I'd like to do some comparisons in cooler fall weather, I wish that I had some more instrumentation in my arsenal.

 

Could be. Rod and I are both in Florida. Jim, you are running stock injectors too, right? I think my SL55 was dying but I am glad I got the 550's for growing room and the smoother idle. I'm going to take the time soon to see what combo might ngive more torque between 2500 and 4500rpm. Might be worth a pulley change but it is running so nice I'd like to ndo the ehaust and call it done! Good luck to all. Mark

 

I actually live in Maryland.

 

Does anyone know is there is enough material to machine down the eurocharged 64.7mm pulley to around 61. If so I might send mine to jefasold's guy so I don't have to mess around with doing a stacked setup.

 

No, emphatically! With the OEM pulley being 74 mm, I think that I wouldn't go beyond 69mm. If you are looking to stack, that should be plenty, if not, then go with an aftermarket pulley.

 

I was talking about machining an aftermarket 65 pulley down to 63 or 62