Best cam options for boosted application

[Carbuff91]

So, I have some stock heads I plan on cleaning up and possibly putting in some stronger springs since I will be revving around 7K and pushing 20pds of boost (turbo). My goal with a built motor is to get around 700 to the rear. I'm looking for some good cam options that can get me there. I don't want anything too crazy because this car does get driven on the street (not a daily driver though).
Thanks for any advice,
Steve

 

[07 Boss]

First off this isn't tech so you will get flamed and moved.

Second, just look for the largest LSA available for the duration and lift that you are looking for. Blower cams will generally have a slightly longer exhaust duration than an N/A cam with a given intake duration. So be sure to look for that when choosing a cam.

I would also look into swapping out the tranny too. I would be leery about putting that much power through any 5R55S unit no matter how "built" it is.

 

[Carbuff91]

Ok, sorry about posting in wrong section. Thanks!

 

[46addict]

Comp 127550s have been used to reach that power level. But if it were me I would choose a milder cam like a 127350 and rely on boost to make up the difference. You're going to want VCT limiters or lockouts with these cams.

Are you still on the stock bottom end?

 

[Carbuff91]

46addict, why would you use a milder cam? This isn't a daily driver and may see the track a few times a year. I like the powerband of the 127550 cam and I did plan on buying the stronger comp cams valve springs for high lift/revs. I'm building the block with a forged bottom end and h-beam rods as well.

 

[46addict]

Just personal choice. I haven't seen dyno curves of the 127550s but I would think the smaller cams are less "peaky". And cam selection is not as critical on a boosted car because you can make up any power differences between the two cams with boost, like I mentioned before.

 

[Department Of Boost]

I myself would run stock cams and then IF it didn't make the power I wanted then I would put some cams in.

700 on stock cams shouldn't be an issue.

 

[Carbuff91]

I myself would run stock cams and then IF it didn't make the power I wanted then I would put some cams in.

700 on stock cams shouldn't be an issue.

What do you think about locking out the VCT or completely deleting it? Do you think it's a good move to do that or just stick with it as is? I plan on pushing the rpm's around 7K and 18-20pds of boost on a built bottom end. I'm also running an automatic.

 

[drive_55_not]

What do you think about locking out the VCT or completely deleting it? Do you think it's a good move to do that or just stick with it as is? I plan on pushing the rpm's around 7K and 18-20pds of boost on a built bottom end. I'm also running an automatic.

If you're swapping cams, lock the VCT and get a set of custom cams made for LO's, the VCT can't handle big cams and 15+psi of boost.

If you lock VCT cams you'll lose a little power, I lost 20hp from 5500rpm up when I locked custom grinds, but the torque stayed the same.


.

 

[weather man]

Search

http://www.s197forum.com/forum/showthread.php?t=62653&highlight=cam

 

[sdleo29]

Thanks for the link!!! Lots of good info there, saved me a search. I have a built short block, with stock cams and heads. I can't leave well enough alone and want to add cams and of course need to change springs, limiters or lockouts etc... I am only looking to get 700 to wheels with boost, but love the sound of a cam

 

[07 Boss]

If you're swapping cams, lock the VCT and get a set of custom cams made for LO's, the VCT can't handle big cams and 15+psi of boost.

If you lock VCT cams you'll lose a little power, I lost 20hp from 5500rpm up when I locked custom grinds, but the torque stayed the same.


.

You know that is impossible, right? If torque stayed the same, HP has to stay the same.

If you lost 20 hp at 5500 rpm you lost 21 ftlbs of torque. Do the math.

 

[Racer47]

he probably means the torque peak stayed the same, maybe torque peaked at 4500 rpm. but then on the high end, above 5500 he lost power (and torque)

 

[drive_55_not]

he probably means the torque peak stayed the same, maybe torque peaked at 4500 rpm. but then on the high end, above 5500 he lost power (and torque)

^^ This, we were able to recover the lost low end torque and as noted, with locked cams, power dropped after 5500.



.

 

[AbdullaGT500]

Comp 127550s have been used to reach that power level. But if it were me I would choose a milder cam like a 127350 and rely on boost to make up the difference. You're going to want VCT limiters or lockouts with these cams.

Are you still on the stock bottom end?

I ran those cams without limiters or lockouts with 18 PSI on a 3v car with no issues.

 

[46addict]

They're both spring required cams, and heavier springs will wear down the VCT faster. You may have run them on the stock phasers with no issues, but that doesn't mean they're going to last.

 

[AbdullaGT500]

They're both spring required cams, and heavier springs will wear down the VCT faster. You may have run them on the stock phasers with no issues, but that doesn't mean they're going to last.

They held up fine with well over 10k miles. Ended up selling the motor when I parted the car out so I'm not sure how much longer they kept going for.

 

[Carbuff91]

I may just stick with the stock cams and get some new springs and spend cam money elsewhere. If I don't get the stiffer springs I suppose I should be fine. I'll just have the trans programmed to shift closer to 6800.

 

[46addict]

That would be the most cost effective way.

 

[eighty6gt]

I'm rolling the dice and running the 26113 comp springs without any phaser mods, 127300 cams.

Hoping the car sounds a little grouchy at idle and I get 25 extra wheel horsepower, with 11+ psi.