Diferance between blower cam and turbo cam ???

I have a couple of 481x's that I am converting to twin turbo., What is the differance in a blower camshaft and a turbo cam ? Other than Pro-line, Who would have the best Idea on the best cam for a twin turbo 481x ?

 

i got my cam from AJPE thru bullet its 276/276 .500/500 lobe 1.8 int /1.6 rocker ratio the blower cam it 296/296 .500 lobe

 

When I switched from blower to twin turbo (BBC), I used the blower cam with good results for a couple seasons tweaking our setup (my fuel system design). For this season, I am switching to a "turbo" cam. I use Lunati and David Chamberlain there has been a great help. Don't have the specs in front of me, but in the post above sounds close. However, I am a tractor puller (mini rod), so usage is a little different. JW

 

Are those the high ratio rockers you have ? How big do they make your cam ? 900 + lift ? , What valve springs do you run ?, So it looks like they only change the duration ? Thanks so much for the reply's. Trying to put this all together my self.

 

Any decent blower cam will work "okay" but if you want to really get the most from the turbos you will definitely need a different cam profile made for your application. The difference will not be trivial in terms of total performance, by doing so.

Assuming you have the correct turbos (housing sizes, compressor wheels, exhaust turbine wheels, etc....., big choices of themselves) your turbo engine will actually operate in an environment more like that of a naturally aspirated engine than that of a positive supercharged engine, due to the breathing ratio (pressure ratio) that exists between the intake runner and the exhaust runner while under boost. The exhaust turbine wheel will also be sensitive to the delivered exhaust gas mass/energy/velocity.

My recommendation would be this. Gather together all of the specs that you can for your turbos, short block, and head flow. Then talk to the likes of Comp, Crane, Lunati, and other cam companies. They can provide a wealth of info. Small changes in profiles, lobe angles, and lobe separation angles can pay big dividends. Also, their tech lines and advice are free and very accesible. They are oriented toward selling you the best cam for you application, not the one on their shelf.

Hope that helps. You didn't say specifially, but are you going EFI? Alcohol or gas? Intercooled or non intercooled?

 

cam

keep the blower cam in it...it will make the transition to a screw easier when you decide you want to go fast...hahahaha

 

Running the steel T&D rockers AJ recomends them for the turbo combo i have PAC 1360 duel 1.500 springs after 50 laps last year they were only down from 475 to 430 -450 going to run them again also have the manely captiv loc Ti locks the 276/276 cam was a spec cam AJ sells. In talking to the guys at bullet with my engine/clutch combo we re ground the ext side to 281

The 481 will make enough power to send the local screw blowers home or respect you enough they won't see you as a duck in the staging lanes lol

 

Twin gen 2 94mm turbo's, EFI, Alky, All Billet Hogan Intake, 526cui and 550cui. Stage 1 heads, Bruno-2 and 3 spd. Lenco. I just want to make sure I get the best cam for my application, Im sure every cam company will tell me there's is the best LOL. Thanks for the Reply's!!! PS. 2900lb. Outlaw 10.5 car.

 

Lmao I like this one Nick cj

 

I just saw this. That's funny as hell.

 

I have allready bin down the screw blower road before,( Lot of parts ie.Belts,bearings, oil,Rods,valve springs ). 481x TT will be easyer on parts. Dissomma Racing engines is doing the build now. Pro-Line would'ent call back. Thanks Guys for the help.

 

lol 86 runs shifting @9000 same valve springs 475 on seat new 450 now