New big cam, lots more turbo lag??

[Guest jcushing]

290/280 duration isnt so extreme that you would loose power everywhere. so i would suspect they were off at installation

 

the fact that you had to lean the entire powerband out obviously means you lost power everywhere. the fact that your loosing vacuum not just at idle, but also while cruising compared to the stock cam means your loosing too much of your cyl charge to overlap. now with a great flowing top end and a turbo this is almost never a problem once you get into boost (its just getting into boost that is the problem, hence why wild profiles are mostly for drag only) but since you had to lean out even in boost this means your top end wasnt up to the task. if your reaching your desired boost level with a rather large turbo id say its not your exhaust side, rather your intake side.

 

were you given cam cards for these cams?

 

this is exactly why cams are not bolt ins and need to be degreed in, especially regrinds, since when grinding the base circle, the LSA's and lobe profiles can change from the stock profile making the stock timing mark on the cam invalid. if your 100 percent sure that the cam was installed in the most correct position when you were having problems it could be that it just needed to be dialed in a bit. a cam thats too retarted will have very low vacuum at idle, and poor low speed performance with a really fast ramping TQ curve (that can make it "feel" like your accelerating faster than before). on the otherhand a cam too "wild" will have too wide of an LSA and do the same thing so you can be sure unless you know that its installed correctly if it was too big. if you have to large of a cam, advancing it will move your power band lower, and idle better at the expense of top end.

 

the first step would be to get an adjustable cam gear, and then degree it in, hopefully with the cam card. if you dont have a cam card, try and contact the company and at least get the centerline the cam should be installed at.

 

all you need is a degree wheel, and 2 dial indicators, one in a spark plug hole to find TDC, and another on a retainer or something to get actual valve lift. you will need 0 lash if your going to use the advertised duration method of degreeing (keep in mind advertised duration, the duration specs your listing, can be off and duration at .05" is usually more accurate) . any lash will work for peak lift meathod (since your only using the peak of the cam lobe and matching that up to a specific degree mark).

 

if you guys are interested a buddy of mine has basically made a living developing cam degree fixtures specific for certain motors, all he needs is a spare head if enough people are interested in having one developed. his kits come with wheels, indicators, and fixtures for mounting to specific head configurations.

[jeffer949]

Little off subject but can you use a NA cam core to lets say have isky grind a turbo grind onto it?

[Guest jcushing]

turbo cams are typically very high lift with a medium-medium long duration (just there to attain the lift while maintaining a sane ramp angle), regrinds are typically only able to get a few hundreths of lift over the stock profile because you cant grind too much of the base circle without affecting your rocker/lifter.

[WizardBlack]

Little off subject but can you use a NA cam core to lets say have isky grind a turbo grind onto it?

 

Call and ask Ron. He is pretty cool to talk to.

[WizardBlack]

before I went turbo (I think?) the car started running bad one day. Took the valve cover off to find the cam had broken.

 

Sounds if it happened twice it must be a funky head/tower issue. Otherwise, we're gonna have to name your car the cam-breaker.

[blackwidow]

I'm pretty sure i read most of the posts, but has anyone taken any of these turbo cams and done backpressure tests with datalogging. It would be nice to know how these cams are really doing. From my experiance turbo cams should be designed mostly with backpressure in mind. Also the only turbo cams that have any sort of overlap should be ones that the turbo has been matched to the motor or you will have reverse filling because of the backpressure that the turbo creates just by being in the system. This tends to happen at lower rpms which could also cause what the OP was experiancing in the first place.

[WizardBlack]

I'm pretty sure i read most of the posts, but has anyone taken any of these turbo cams and done backpressure tests with datalogging. It would be nice to know how these cams are really doing. From my experiance turbo cams should be designed mostly with backpressure in mind. Also the only turbo cams that have any sort of overlap should be ones that the turbo has been matched to the motor or you will have reverse filling because of the backpressure that the turbo creates just by being in the system. This tends to happen at lower rpms which could also cause what the OP was experiancing in the first place.

 

Backpressure depends on a lot of other factors aside from the cam, obviously. I do believe some guys were playing with backpressure, but I am not sure if this one was tested. The odd thing is that the car isn't behaving the way they normally do with this cam.

[blackwidow]

Backpressure depends on a lot of other factors aside from the cam, obviously. I do believe some guys were playing with backpressure, but I am not sure if this one was tested. The odd thing is that the car isn't behaving the way they normally do with this cam.

 

Understandably so. It would be cool to have a cam sticky. One with all the specs of every cam we could get our hands on even stock. I will search for one. if there is not one, maybe i could work on one.