Cams on pullied eaton ?

[Frankycheechoo]

Hi guys just wondering can u put cams on a stock cobra motor just pullied and tuned ? What stage be best , is there anything more u have to do ?



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[03' White Snake]

1. Yes you can add cams to a stock motor. I'd say stage 2 or go custom grinds based on your future goals.
2. Cams are a very expensive upgrade, easily 2k, and that's if you do the work yourself. I'd guess 3k if you had a shop install them. Very little hp for $ value. Cams are 75% for sound alone. Cams~$1200, springs~$400, valve seals~$80, timing gears~$400.
3. Buy a bigger blower and make 150 more hp vs 2k for 20 hp.

 

[Frankycheechoo]

Thanks for the reply .
I know they won’t add much power it’s the sound I’m after I would eventually want a bigger blower for sure that’s the goal . If I would go woth a stage 2 and later on add the bigger blower does that mean the cams have to be upgrade too ? Don’t want to have to do it twice yea know!
Thanks fir the info ?
What’s your take a bigger throttle body how much more power will it add ? Or is it bit worth it for just a pullied tuned set up ?
What about upper lower pulley combos ? Thanks


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[SecondhandSnake]

Note that the typical lopey cam sound is from overlap. That is less desirable with a blower cam, as it allows the boost to escape through the exhaust.

You don't have to upgrade cams if you have a bigger blower. It is an option though, depending on what your goals are.

The throttle body isn't a huge concern with a stock blower. It becomes more important as your power/airflow go up. The gains will depend on your blower size and boost pressure combination.

 

[TerminatoRS]

Aren’t there some drivability concerns that go along with cams? Specifically and depending how aggressive the cams are, getting the car moving without killing it and/or frying the clutch. I thought that’s why it’s recommended to go to a 3.73 or 4.10 rear gear.


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[Black02GT]

Aren’t there some drivability concerns that go along with cams? Specifically and depending how aggressive the cams are, getting the car moving without killing it and/or frying the clutch. I thought that’s why it’s recommended to go to a 3.73 or 4.10 rear gear.


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I have 3.73, no issues. My $0.02 waste on an Eaton car, boost drops off top end anyway. Not worth trading low end torque for top on HP with that blower. Big blower, yes HP to be had shifting the powerband up. Should be shifting before the cams really wake up with a stock blower.

Dont waste the money, sound at idle and WOT is Godlike with long tube and cams on a TVS and up car. Honestly dont know if I really gained much and lost some bottom end. Cool but not a performance mod when it comes to calculating dollar per pony at all on an Eaton. Worth it if you're already building the engine...maybe. (my situation). Did make over 725 rwhp on 2.8 upper only TVS which is no slouch but also 10.6 CR. So a lot more involved.

 

[olympic]

Aren’t there some drivability concerns that go along with cams? Specifically and depending how aggressive the cams are, getting the car moving without killing it and/or frying the clutch. I thought that’s why it’s recommended to go to a 3.73 or 4.10 rear gear.

Agressive cams can definietely cause all the driveability issues you mentioned and more. I bought my car with Stage 4 Crower cams and swapped them out for stage 2's last year. The only thing good about the 4's was the choppy idle. Any kind of low speed driving was always a PITA and IAT2's would spiral out of control if I drove in city traffic for any amount of time. Lower rear gears won't help and will just make your first 2 gears completely useless.

A PD blower like ours needs strong intake vacuum for the bypass valve to operate properly. When you install big cams with lots of overlap, you kill the intake vacuum so the bypass flutters open/closed while crusing or just stays closed causing all the problems mentioned above. A low vacuum bypass actuator can help but will cause driveability issues of it's own such as an annoying surge when transitioning from vacuum to boost.

If you are dead set on cams, I would strongly recommend going through Todd "NA SVT" Warren over on his facebook page. He can spec you some cams based on your build and recommend how to degree them to meet your goals. Mild cams can have a choppy idle with enough overlap dialed in and agressive cams can idle like stock if degreed properly. It all depends on your goals.

Here's my car with Crower Stage 2's. Idles and drives nearly stock.


Here it is with Stage 4's . Sounds great!


Here I am struggling just to drive it off the lift before the engine has warmed up...lol!

 

[Black02GT]

Agressive cams can definietely cause all the driveability issues you mentioned and more. I bought my car with Stage 4 Crower cams and swapped them out for stage 2's last year. The only thing good about the 4's was the choppy idle. Any kind of low speed driving was always a PITA and IAT2's would spiral out of control if I drove in city traffic for any amount of time. Lower rear gears won't help and will just make your first 2 gears completely useless.

A PD blower like ours needs strong intake vacuum for the bypass valve to operate properly. When you install big cams with lots of overlap, you kill the intake vacuum so the bypass flutters open/closed while crusing or just stays closed causing all the problems mentioned above. A low vacuum bypass actuator can help but will cause driveability issues of it's own such as an annoying surge when transitioning from vacuum to boost.

If you are dead set on cams, I would strongly recommend going through Todd "NA SVT" Warren over on his facebook page. He can spec you some cams based on your build and recommend how to degree them to meet your goals. Mild cams can have a choppy idle with enough overlap dialed in and agressive cams can idle like stock if degreed properly. It all depends on your goals.

Here's my car with Crower Stage 2's. Idles and drives nearly stock.


Here it is with Stage 4's . Sounds great!


Here I am struggling just to drive it off the lift before the engine has warmed up...lol!

I have stage MMR stage 3 which has an idle but not bad in traffic. I live in downstate NY and doable but adjustable gears and degree work on all 4.

No doubt my high static compression helps the lower dynamic compression from the cams. Honestly the low lift flow of C heads dont need cams tills you get to the "**** it I've done everything else stage". I did it to max out a 2.3 which I think is a great street blower for all around. Before that no need, honestly could got a 2.9/3.0 now and made more. All e85 talk though, maybe on lower octane power to be had with less boost?

Todd is the way to go, talk to him. Only got MMR cause they built one of my last engines and price was right while they were doing it. Fun 2,000 miles (cough) new local builder is not a fan.

Not to mention the massacred my cams supports to make them fit...

 

[SecondhandSnake]

Aren’t there some drivability concerns that go along with cams? Specifically and depending how aggressive the cams are, getting the car moving without killing it and/or frying the clutch. I thought that’s why it’s recommended to go to a 3.73 or 4.10 rear gear.

The driveability concerns come with high overlap cams due to less idle stability and low vacuum. Those types of cams are also poorly matched to a PD blower car, especially a stock Eaton. It would not really improve the car except sound wise, and even that is debatable.

Things like gearing should be matched to the cams through to help keep the car in the desired power band though.

I have 3.73, no issues. My $0.02 waste on an Eaton car, boost drops off top end anyway. Not worth trading low end torque for top on HP with that blower. Big blower, yes HP to be had shifting the powerband up. Should be shifting before the cams really wake up with a stock blower.

Cams can definitely be a help with an Eaton car, but like you said ones that are high overlap, high RPM would be a huge waste. A bigger set of cams would be useful but it would be something with a lot less overlap and probably advanced a few degrees to better match the engine/blower. I ran mine with a 114 LSA +3 deg advanced and it seemed pretty happy.

 

[stangfreak]

These guys nailed it.

The only time I would do cams, is if I am rebuilding the motor. I will not do cams on my stock motor. Id rather up the boost or buy a different blower.

 

[chada1208]

No need for cams. When I bought my cobra it had stage 2 Comp cams, sounds really good but drove like shit. Cuts off at idle, would take 2-3 times to start. It was a stock motor with ported blower 2.93 upper 6lb lower it made 525whp 570wtq. Later on I built the motor and got bullet custom turbo cams and it was a night/day difference. Way better drivability. Imo go with custom cams spec to what you want for the car.

 

[01yellercobra]

No need for cams. When I bought my cobra it had stage 2 Comp cams, sounds really good but drove like shit. Cuts off at idle, would take 2-3 times to start. It was a stock motor with ported blower 2.93 upper 6lb lower it made 525whp 570wtq. Later on I built the motor and got bullet custom turbo cams and it was a night/day difference. Way better drivability. Imo go with custom cams spec to what you want for the car.

That sounds like you had tune issues.

 

[03cobra#2]

No need for cams. When I bought my cobra it had stage 2 Comp cams, sounds really good but drove like shit. Cuts off at idle, would take 2-3 times to start. It was a stock motor with ported blower 2.93 upper 6lb lower it made 525whp 570wtq. Later on I built the motor and got bullet custom turbo cams and it was a night/day difference. Way better drivability. Imo go with custom cams spec to what you want for the car.

For sure sounds like the tune needs a little tlc. You can get these cars to run well with cams but it takes time and attention in the tune.

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[chada1208]

That sounds like you had tune issues.

Myra when I first received the car it had a shitty tune on it. Even after I got it returned it still had issues with the cams. After I went with custom cams it was totally different