MSD 2 step launch control & cats

[joedls]

I've launched my car ~10-12 times with the MSD 2 step. I started getting worried after reading on several boards that the 2 steps were ruining people's cats, so I purchased an off-road X-pipe. I took the car over to RET today to have them install the X-pipe and give me a 100 octane tune. I just got a call from Greg, saying that it's a good thing we removed the cats because they were already clogged.

So just an FYI, if you run a 2 step, don't run cats.

[SeanPlunk]

I've launched my car ~10-12 times with the MSD 2 step. I started getting worried after reading on several boards that the 2 steps were ruining people's cats, so I purchased an off-road X-pipe. I took the car over to RET today to have them install the X-pipe and give me a 100 octane tune. I just got a call from Greg, saying that it's a good thing we removed the cats because they were already clogged.

So just an FYI, if you run a 2 step, don't run cats.

Bummer, thanks for the head's up. More importantly though, what did the car put down?

[joedls]

Bummer, thanks for the head's up. More importantly though, what did the car put down?


Don't know yet. He just finished installing the X-pipe. He was getting ready to tune it. I'll pick it up in about an hour.

[SeanPlunk]

Cool, post up when you get numbers. I'm going to eventually get an x-pipe for my car too, but I'll probably get a catted one. Identically modded cars are making about +10-15 RWHP with them, so it's definitely on my list. I don't want to risk getting fined for no cats though so no off-road pipe for me :o

[SeanPlunk]

By the way Joe, I'm planning on going to the dyno day at RET on the 20th. I'm not going to dyno, but I'm going to go hang out. Are you interested?

[joedls]

By the way Joe, I'm planning on going to the dyno day at RET on the 20th. I'm not going to dyno, but I'm going to go hang out. Are you interested?


I wasn't planning on it. My social director(wife) probably wouldn't be too happy if I did, since I'm going racing this weekend and next weekend, too. But I might be able to get away for a little while.

[SeanPlunk]

I wasn't planning on it. My social director(wife) probably wouldn't be too happy if I did, since I'm going racing this weekend and next weekend, too. But I might be able to get away for a little while.

LOL, believe me, the last thing I would want to do is get you in trouble with your social director :drink:

[SeanPlunk]

Oh, and does your car have a forged bottom end? I'm just curious because with the blower and nitrous I'd have to guess you're in the 525-550RWHP range at least depending on the size of the shot....

[joedls]

Oh, and does your car have a forged bottom end? I'm just curious because with the blower and nitrous I'd have to guess you're in the 525-550RWHP range at least depending on the size of the shot....


No, I'm not forged. That is what is limiting the size of the shot. I'm spraying a 50 HP shot now. I made 470 RWHP and 498 lb-ft of torque today. That's 20 peak HP more than my last dyno session, but a whopping 42 lb-ft of peak torque increase. From 4000 RPM to about 5500 RPM, I'm making 30 - 40 more HP than my last session.

I believe I'm pretty much pushing it with my stock internals now.

[SeanPlunk]

No, I'm not forged. That is what is limiting the size of the shot. I'm spraying a 50 HP shot now. I made 470 RWHP and 498 lb-ft of torque today. That's 20 peak HP more than my last dyno session, but a whopping 42 lb-ft of peak torque increase. From 4000 RPM to about 5500 RPM, I'm making 30 - 40 more HP than my last session.

I believe I'm pretty much pushing it with my stock internals now.

Then you can blow it up and make it faster :bigthumbsup:

[SeanPlunk]

Stout numbers by the way :hail:

[joedls]

Then you can blow it up and make it faster :bigthumbsup:


Yeah, but not until I get my 68 back on the road.

[BlacknBoostn]

Wow nice numbers Joe! With the 2 step you should be breakin into mid elevens I think!!! I was planning on of those for the SRT4 when I have more power to spin my tires with... The fastest 2 SRT4s I know of both use a WOT Box or 2step... one is mid to high 9s, other is best time 10.97 ET

[SeanPlunk]

Someone educate me, what is the 2 step actually doing?

[BlacknBoostn]

Someone educate me, what is the 2 step actually doing?

Essentially launch control. You set it at a certain RPM and it sets a rev limiter for that RPM. You floor it clutch in and staged and let the 2 step or WOT box control your launch. Clutch out, 2 step stops. All about consistency

[BlacknBoostn]

For you Sean

YouTube - Cobra 2 step car for sale

YouTube - 03 cobra 10.73 run

[SeanPlunk]

Essentially launch control. You set it at a certain RPM and it sets a rev limiter for that RPM. You floor it clutch in and staged and let the 2 step or WOT box control your launch. Clutch out, 2 step stops. All about consistency

That's awesome! I wonder why it's frying cats though? So basically you can set the limiter at 3k, and it will launch at that RPM, but then how does the box know to let you rev it past that after you've launched? You must have to arm it after the waterbox?

[SeanPlunk]

For you Sean

http://www.youtube.com/watch?v=VODoVnmmavY

http://www.youtube.com/watch?v=-wD_YAaJY1M

I think that 1st Cobra may have some slightly bigger than stock cams....

[joedls]

That's awesome! I wonder why it's frying cats though? So basically you can set the limiter at 3k, and it will launch at that RPM, but then how does the box know to let you rev it past that after you've launched? You must have to arm it after the waterbox?

My 2 step is activated with a switch on my clutch pedal. Once I release the clutch pedal it deactivates, then will not reactivate when depressing the pedal unless it falls at least 1000 RPM below the limiter. So, for example, mine is currently set at 3500 RPM. Once I release the clutch pedal, it will only reactivate once it falls below 2500 RPMs while the clutch pedal is depressed.

The reason it is killing cats is because it's cutting spark, but fuel is still at WOT. So you're dumping unburned fuel directly into your exhaust.

[BlacknBoostn]

My 2 step is activated with a switch on my clutch pedal. Once I release the clutch pedal it deactivates, then will not reactivate when depressing the pedal unless it falls at least 1000 RPM below the limiter. So, for example, mine is currently set at 3500 RPM. Once I release the clutch pedal, it will only reactivate once it falls below 2500 RPMs while the clutch pedal is depressed.

The reason it is killing cats is because it's cutting spark, but fuel is still at WOT. So you're dumping unburned fuel directly into your exhaust.

I knew the second part, but wasn't sure about the technical setup.. good info! so you can actually have that fully engaged throughout your run right Joe?

[SeanPlunk]

My 2 step is activated with a switch on my clutch pedal. Once I release the clutch pedal it deactivates, then will not reactivate when depressing the pedal unless it falls at least 1000 RPM below the limiter. So, for example, mine is currently set at 3500 RPM. Once I release the clutch pedal, it will only reactivate once it falls below 2500 RPMs while the clutch pedal is depressed.

The reason it is killing cats is because it's cutting spark, but fuel is still at WOT. So you're dumping unburned fuel directly into your exhaust.

Thanks for the explanation Joe (Tyler too). Pretty trick stuff :bigthumbsup:

[BlacknBoostn]

Thanks for the explanation Joe (Tyler too). Pretty trick stuff :bigthumbsup:

YAH! Almost a necessity for us FWD boosters... HAH. BTW Sean, I answered the thread about your top car... pic included :thumbs_up:

[joedls]

I knew the second part, but wasn't sure about the technical setup.. good info! so you can actually have that fully engaged throughout your run right Joe?


Mine is always activated when the clutch pedal is depressed and the RPMs are under 2500. If it's over 2500 RPM, the rev limiter won't kick in, so then the rev limiter in my computer takes over. That is set at 6500 RPM.

[SeanPlunk]

YAH! Almost a necessity for us FWD boosters... HAH. BTW Sean, I answered the thread about your top car... pic included :thumbs_up:

I saw, good choice. I got to see a RHD one at the place I bought my Camaro SS from back in 2000 :D

[joedls]

YAH! Almost a necessity for us FWD boosters... HAH.

It's a necessity for a mediocre driver like me. Too many things to concentrate on at the line. This takes away one of them. I don't have to try to hold a certain RPM. I depress the clutch and throttle pedal, wait for the light, and side-step the clutch.

[BlacknBoostn]

I saw, good choice. I got to see a RHD one at the place I bought my Camaro SS from back in 2000 :D

Hm. Just edited. Either that or a 1969 Camaro SS. So beautiful.

I would kill to drive a r34 though...

[BlacknBoostn]

It's a necessity for a mediocre driver like me. Too many things to concentrate on at the line. This takes away one of them. I don't have to try to hold a certain RPM. I depress the clutch and throttle pedal, wait for the light, and side-step the clutch.

I'm too new to drag racing, and my car is stock :bang: so really not too much of a point yet...

[2011GT302]

Wait I thought the MSD 2-step also hooks up to the injectors. So if your still dumping gas what is the point for that?

[joedls]

Wait I thought the MSD 2-step also hooks up to the injectors. So if your still dumping gas what is the point for that?

Nope, just your COPs. It cuts spark to limit the revs.

[2011GT302]

Hm. Just edited. Either that or a 1969 Camaro SS. So beautiful.

I would kill to drive a r34 though...

LOL I've been in a r33 and r34 they are nothing special. Then again they were both stock.

[SeanPlunk]

LOL I've been in a r33 and r34 they are nothing special. Then again they were both stock.

Stock R33 and 34's exist? That's like finding a unicorn or something :sm_laughing:

[2011GT302]

Well then I'm just going to have to working on my driving cuz my stang still has cats.
but I run slicks so the 2 step would be nice.

[2011GT302]

Stock R33 and 34's exist? That's like finding a unicorn or something :sm_laughing:

the R33 was stock at the time shortly after that changed to the tune of about 800 horses but that was like 6 or 7 years ago and belonged to a not so close friends that just had too much money. Spoiled brat.
the r34 belonged to motoX and they had just brought it over.

[BlacknBoostn]

LOL I've been in a r33 and r34 they are nothing special. Then again they were both stock.

You're lucky! I've seen them once or twice on the street... but not really closely enough to really see

[joedls]

Here's the dyno sheet from yesterday. The blue is from the last tuning session. The red is the latest.


http://img258.imageshack.us/img258/858/gtcsdyno001tg7.jpg

[BlacknBoostn]

Here's the dyno sheet from yesterday. The blue is from the last tuning session. The red is the latest.


http://img258.imageshack.us/img258/858/gtcsdyno001tg7.jpg

:bigthumbsup: Good numbers!

[SeanPlunk]

Here's the dyno sheet from yesterday. The blue is from the last tuning session. The red is the latest.


http://img258.imageshack.us/img258/858/gtcsdyno001tg7.jpg

The image is blocked from work, but I'll check it out as soon as I get home.

[enkeivette]

Cool, post up when you get numbers. I'm going to eventually get an x-pipe for my car too, but I'll probably get a catted one. Identically modded cars are making about +10-15 RWHP with them, so it's definitely on my list. I don't want to risk getting fined for no cats though so no off-road pipe for me :o

That's why I run cats and decided never to go with those cool sidepipes. I think it's something like a $25K fine.


Joe did you gain almost 20hp after 5 dyno runs? Did you guys just dick around with the fuel and timing? Or did you change the nitrous jets? Are you running a wet system?

[joedls]

Joe did you gain almost 20hp after 5 dyno runs? Did you guys just dick around with the fuel and timing? Or did you change the nitrous jets? Are you running a wet system?


I don't know how many runs he did. I wasn't there. We bumped the nitrous up to a 50 HP shot, from a 35 HP shot. Yes, I'm running a wet system with a window switch.

[BlacknBoostn]

That's why I run cats and decided never to go with those cool sidepipes. I think it's something like a $25K fine.


Joe did you gain almost 20hp after 5 dyno runs? Did you guys just dick around with the fuel and timing? Or did you change the nitrous jets? Are you running a wet system?

UGH 25k fine to run no cat? Wow. Maybe I'll run a high flow... Maybe 3in catted DP with an E Cutout...