Cam options

[Jake Schmale]

Hey everyone, I’ve decided to get a set of cams and purchased a set of comp Mutha Thumpr 127020 cams. I’m not really worried about sound as much as performance. I’ve read these can increase power up to 25+ with the right supporting modifications. So is anyone using these cams? If so how do you like them. A guy at jegs tried talking me into the Lunati voodoo part #21270704 cams but I purchased these instead. Hopefully I made the right decision. The only difference between these two cams was the lobe separation angle 116 vs 109 and the lift at 50 which was more on the voodoo cam but it had less overall duration than the Mutha Thumpr. Both had .450 lift.

 

[RED09GT]

The 116 LSA of the Lunati cams will make it pretty doggy in the midrange. The ones you chose should have a higher torque peak than the Lunati with giving up less than 10 hp at high RPMs.

 

[07 Boss]

Just some friendly advice. Cams should be the last thing you get to tune the power band of your set up. Things to take into consideration would be your goals, the type of driving, convertor stall speed (if auto), rear end gears. etc. When you look at cam specs you have to look at them together and not individually. They all work together. Some valve overlap is desirable and depending on your set up your going to want more or less. Generally those sound cams have more overlap than is really necessary and bleed power just for the sake of a rough lumpy idle.

You need to tell us more if you want some relative advice. What are your goals? Are you ever going to change the induction or exhaust? What gears do you have? Manual or auto? Daily driver, weekend warrior, race car? So many factors need to get incorporated in order to make the proper choice.

 

[Jake Schmale]

Just some friendly advice. Cams should be the last thing you get to tune the power band of your set up. Things to take into consideration would be your goals, the type of driving, convertor stall speed (if auto), rear end gears. etc. When you look at cam specs you have to look at them together and not individually. They all work together. Some valve overlap is desirable and depending on your set up your going to want more or less. Generally those sound cams have more overlap than is really necessary and bleed power just for the sake of a rough lumpy idle.

You need to tell us more if you want some relative advice. What are your goals? Are you ever going to change the induction or exhaust? What gears do you have? Manual or auto? Daily driver, weekend warrior, race car? So many factors need to get incorporated in order to make the proper choice.

The car is a 5 speed manual, and I use it for street/strip and maybe drive it twice a month. It already has 1-3/4 inch long tube headers, Off road mid pipe, 4.10 gears, CMDP, Underdrive pullies, Lito E-85 tune. I’m looking to get the most out of it NA right now without digging too deep into the motor like doing valve springs or cylinder heads. At the race track I keep it below 6,500 rpm.

 

[retfr8flyr]

I would recommend sending the Mutha Thumpr cams back. The MT cams are more for sound then performance. If you are trying to get the most out of it NA there are much better cams out there. I would give Comp Cams a call, they have a department just for helping you choose the best cam profiles. Their custom grinds are the same price as off the shelf and they may be able to recommend something better. If you are not changing springs, then you are limited as too how much cams will help you. I would save up a little more and do some good springs while you have it torn apart.

 

[JeremyH]

The thumpers have a really tight separation and more duration to promote open valve overlap. This creates reversion and drops idle vacuum in turn recreating a lope or choping idle sound from exhaust gas flowing back into the chamber and manifold. Which is typically a negative side effect for an agressable top end power cam on a pushrod motor. There was a big lope sound cam trend that started for the 3v and half a dozen companies started making them including Ford with the hot rod cams. Typically you would compensate for a tight lsa long duration cam by raising idle rpm and steeper gear to get you to top end quicker. Tight lsa makes all its power up top 6k rpm +
The voodoo cam you mentioned will have a more uusable/wider poweband often refered to as power under the curve.

Since both cams have same lift they will make similar peak or max hp numbers they will just go about it differently. In summary the mt cam uses tighter lsa and more duration to create the idle sound and will give up low-end to mid hp in favor of more low-end torque and make its peak power north of 6k rpm. The vd cam gives up low end torque and moves peak torque into mid range this broadens the powerband and brings peak power in earlier for more average power under the curve.

This basicly equates to the wider lsa cam having better street manners and being more well rounded. And the tighter being more of a hot rod peak track performer. The stock 3v cams are pretty wide 117.25 lsa for these reasons drivability, mileage, strong idle vacuum, minimal egr effect, fuel economy, taller gears, etc.

 

[07 Boss]

If you're not going to do springs that will limit your options and the available power. Ditch the sound cams and go with Comp, or CMS has a good grind for a NSR cam also.

Though if you want to get the most out of the NA build I would seriously consider replacing the valve springs so you can get a cam that will make a decent impact on power output.

 

[RocketcarX]

The Mutha Thumpr cams constantly outperform almost ALL NSR cams. Spending even a little time on google will confirm this.
I went faster on stock internals and those cams (nitrous car) than all but 3 or so cars chasing that record that I know of.
There is a lot of parroting that goes on as soon as you say the word "cam" in these circles.
Make sure the car has proper gearing (4.10-.430) and you'll be fine.

The car I mentioned above is now a road raced NA car on the exact same engine I used to spray the life out of and recently dyno'd 355 on a 100* day and 100% humidity while making 300+ ft-lbs of torque like a table top. Those cams just plain work!

 

[Olerodder]

The car is a 5 speed manual, and I use it for street/strip and maybe drive it twice a month. It already has 1-3/4 inch long tube headers, Off road mid pipe, 4.10 gears, CMDP, Underdrive pullies, Lito E-85 tune. I’m looking to get the most out of it NA right now without digging too deep into the motor like doing valve springs or cylinder heads. At the race track I keep it below 6,500 rpm.

What kind of times are you turning and what’s your 60’?

 

[GERMANSHEPERD]

Comp 127500 SPR with those on my 4.6 I ran 12.11 at Etown (12.29 here in Ohio) with a 1.71 60’. Those are the ONLY cams I’d run in a stockish 4.6

 

[Jake Schmale]

What kind of times are you turning and what’s your 60’?

Best time, 12.70 best 60 foot 1.69

 

[Doug Huggard]

Comp 127500 SPR with those on my 4.6 I ran 12.11 at Etown (12.29 here in Ohio) with a 1.71 60’. Those are the ONLY cams I’d run in a stockish 4.6

I'm running the blower grind version of those cams (127550) and couldn't agree more! Low compression motor with a tiny VMP 1.9 blower ran a 10.6 with a 1.47 '60 on pump 91 with boostane.

 

[GERMANSHEPERD]

They just work

 

[retfr8flyr]

I have custom Comp Cams in mine, they are based on the 12750 grind but modified for my turbo setup. I have been very happy with them. Comp Cams will make you a custom grind for the same price as off the shelf, if you give them a call.