Switching comp cams with valve springs to FRPP cams or Howards Rattler Cams Help

[PeanutBader]

Hello!
I hope everyone is having a great Sunday and Mother's day!
I have a question about my 2005 Mustang GT
I currently have COMP Cams 127-351-9L & 127-351-9R and COMP Cams Beehive Valve Springs
I am looking into switching to a pair of cams that have a "lopey idle" -- Specifically, the Ford Performance Hot Rod Performance Camshafts if the FRPP cams are not compatible then I was also looking at the Howards Cams Rattler Camshaft
Will there by any issues switching out my current cams for the FRPP cams or the Howards Rattler cams while having the beehive valve springs? I just want to make sure that everything will be running fine! I am also attaching a list of the mods on my car.
Thank you so much for the help in advance!

 

[JC SSP]

Research comp cams spring pressure and compare that with what is recommended on the new cams you want to install.

 

[Midlife Crises]

Comp has more than one set of springs for the 3 valve and both will work with the 127350 series cams. If you don’t know which springs you have you should buy a set of springs recommended for the cams you chose.

 

[JC SSP]

I thought the part number was on that document attached?

 

[PeanutBader]

Comp has more than one set of springs for the 3 valve and both will work with the 127350 series cams. If you don’t know which springs you have you should buy a set of springs recommended for the cams you chose.

I currently have the CCA-26125-24 Beehive springs just don't know if it is okay to run the FRPP cams with it.

 

[PeanutBader]

I thought the part number was on that document attached?

It is. It says CCA-26125-24

 

[Dino Dino Bambino]

I currently have the 249-26125-24 Beehive springs just don't know if it is okay to run the FRPP cams with it.

They're probably overkill for the FRPP cams since they're rated up to 0.610" of valve lift, but it's better to have too much spring than too little.

Swapping out your VSR 127350 cams for FRPP or Howard Rattler cams seems like a backward step to me. Are you sure that's a good idea just for the sake of a lopey idle?

You could just swap to a pair of Borla Atak, Borla Stinger, or Roush Extreme axle-back mufflers instead.

 

[Midlife Crises]

The FRPP and Howard’s Rattler cams claim compatibility with stock springs and the Comp 125 springs are the heavier of the two sets available. They offer more clearance and more seat pressure than needed. The higher seat pressure can ware parts faster.
I am curious, why are running blower cams?

 

[PeanutBader]

They're probably overkill for the FRPP cams since they're rated up to 0.610" of valve lift, but it's better to have too much spring than too little.

Swapping out your VSR 127350 cams for FRPP or Howard Rattler cams seems like a backward step to me. Are you sure that's a good idea just for the sake of a lopey idle?

You could just swap to a pair of Borla Atak, Borla Stinger, or Roush Extreme axle-back mufflers instead.

Thank you so much for your response. I just corrected my post my springs are the
CCA-26125-24. I typed the wrong springs to JC SSP. Photo and info on original post is correct.

I actually just ordered the Roush Extreme Catback! Fingers-crossed that they are loud. Having it installed tomorrow so I can’t wait.

I am not even too sure if my car is cammed I could be wrong but I don’t hear any lopey idle. The person I could have bought it from might have taken it out. It has a smooth idle but not too smooth, still hear a slight “lope” definitely pulls really hard on the higher RPM’s happy to provide a video so that we can identify. I appreciate your time.

I do not mind getting better cams suited for my springs, I just wanted to be safe going backwards if the original owner swapped the springs to stock.

 

[PeanutBader]

The FRPP and Howard’s Rattler cams claim compatibility with stock springs and the Comp 125 springs are the heavier of the two sets available. They offer more clearance and more seat pressure than needed. The higher seat pressure can ware parts faster.
I am curious, why are running blower cams?

Thank you for that info. What’s a good cam to get that would have a good “lopey idle?”

The car I bought the person from recently built the engine to make it into a drag car but moved on to a different project as he had bigger plans.

I never even knew these were blower cams thank you for pointing that out!

 

[PeanutBader]

Here is a video of the stang from cold start to just idling

 

[DieHarder]

Not cammed. Mine sounds very similar. Look up some YouTube vids for examples of lopey/cammed idling.

 

[07 Boss]

Two things. Running a blower cam is going to have a greater LSA so you loose less out the exhaust as the valves overlap. This is going to give you a smoother idle than an NA counterpart.
Second, since you have valve springs already in, there why not run a hotter comp N/A cam like the 127400 or 500? You would have to install VCT limiters or lock outs but you would be going backwards with the hot rod or rattler cams. Maybe you get a lopey idle but you will produce less power. More valve duration and lower LSA will give you that lopey idle you seek while increasing power and moving the power band slightly upward.

 

[Midlife Crises]

The Comp 127350s have less than zero overlap. They are very smooth idling and I would not bet you could hear them. Maybe a hint sometimes. Their characteristic is very strong low and midrange torque. Without a blower I would think they would feel week above 5,000 or so.
I agree with 07 Boss that something in the 127400 or 500 range is a good choice IF, you can tolerate the way those cams act and you are sure you have the springs you think you do.

 

[PeanutBader]

Two things. Running a blower cam is going to have a greater LSA so you loose less out the exhaust as the valves overlap. This is going to give you a smoother idle than an NA counterpart.
Second, since you have valve springs already in, there why not run a hotter comp N/A cam like the 127400 or 500? You would have to install VCT limiters or lock outs but you would be going backwards with the hot rod or rattler cams. Maybe you get a lopey idle but you will produce less power. More valve duration and lower LSA will give you that lopey idle you seek while increasing power and moving the power band slightly upward.

07 Boss, thank you so much for this response and being informative. Contacted the previous owner and he did confirm that the car had the cams I had listed on the original post. He said that it just has a smooth idle for the same reason you mentioned. For the 127400 or 500 cams would I require a cam phaser kit? Is there any way you could provide me with what I need so I could work out the finances?

 

[PeanutBader]

The Comp 127350s have less than zero overlap. They are very smooth idling and I would not bet you could hear them. Maybe a hint sometimes. Their characteristic is very strong low and midrange torque. Without a blower I would think they would feel week above 5,000 or so.
I agree with 07 Boss that something in the 127400 or 500 range is a good choice IF, you can tolerate the way those cams act and you are sure you have the springs you think you do.

Midlife Crises, thank you for this response. Previous owner confirmed the smooth idling as you mentioned. I do notice the strong pull from low to mid range torque. The car lurches forward and sometimes I hit my head. It does feel weak above 5000 as well. My question is what would I need for the 127400 or 500 cams? Any opinion on the Motha Thumpr cams?

 

[MrBhp]

There's a vid out there that does a comparison of several cams. Surprisingly the mutha thumprs produced really good lower mid power, and more than the others from that point on. As to your Roush extreme pipes, that's about as loud as you can get with cat backs. If it's not loud enough, you'll have to remove cats or go to high flow cats, they'll be louder than stock cats.

 

[MrBhp]

Here's mine with roush extreme and high flow cats.

 

[bambam 06]

COMP Cams XFI SPR Modular 3V Camshafts

The COMP Cams XFI SPR Ford 4.6L/5.4L modular 3V (Springs & Phaser Mods Required) camshafts are the best way to achieve the most power and torque increases possible with the popular Ford Modular 3V engine. These designs are the next step up from the COMP Cams VSR (Valve Springs Required) cams. When compared to the VSR cams, the SPR cams offer additional mid-rpm power increases as well as substantial power gains in the higher rpm ranges. In addition to increases in horsepower, you can also expect another 800-1000 rpm of useable engine speed and an awesome sounding idle lope to match.
To achieve this extra level of performance, lobe profiles and timing events were specifically designed to work with the factory variable cam timing (VCT) system cam phasers for all 2005 and newer Ford Modular 3V engines. These cam phasers were modified with the required COMP Cams Cam Phaser Limiter kit to restrict their movement to no more than 20 degrees. This simple modification gains additional piston to valve clearance, allowing for much larger cam designs. This results in cams that not only maintain low and mid-range power, but have incredible high rpm performance as well, all while maintaining the benefits of cam phasing. As noted by the COMP Cams engineering staff during extensive dyno testing, these camshafts provided the biggest power and torque improvements of any cam series they've ever tested in the Ford Modular 3V engine

 

[PeanutBader]

There's a vid out there that does a comparison of several cams. Surprisingly the mutha thumprs produced really good lower mid power, and more than the others from that point on. As to your Roush extreme pipes, that's about as loud as you can get with cat backs. If it's not loud enough, you'll have to remove cats or go to high flow cats, they'll be louder than stock cats.

What is your full setup? Sounds amazing and you got a good looking scheme on the pony! Got my car back today with the Roush extreme pipes, stock mid pipe, stock manifolds and they are loud as hell on startups and when I get on it as well. I did not expect the Roush's to be this rowdy. Love it though! It is about to be a monster on cold starts.

I want to get long tube headers installed coupled with an H-pipe catted but gutted just scared it might be over the top loud!