Jon B.

Just curious if there are a good set of blower/FI cams for 928s? I would think that could be a big limiting factor where power is concerned. I'm used to seeing MANY different cam profiles for my engine since it's an LSX, and it's hard acclimating to the 928 which has little aftermarket type support.

So, anyone offer a good Blower/FI cam/s for a 928? Seems the market is there.

blown 87

You would think so until you find out what blanks cost.
Remember it has a sprocket in the middle.

I do not remember what Greg Brown said the blanks were but I do remember I was shocked.

IcemanG17

The cam options are currently limited to "hard welded" stock cams....or reground base circles....so they are limited to stock cams as a starting point...

There are a few true billet cam blanks out there (3 I think total).... Those were all made by Mike Simard

Doc Brown is looking into getting blank cams from Germany.....but I'm not sure of the progress...

Jon B.

I'd guess that it shouldn't be THAT hard though right? I guess it IS since this 928 performance game has been going on a LONG time before me asking this question. But, in my best Top Gear, Jeremy Clarkson voice, how hard can it be? Has anyone tried reaching any of the big camshaft makers? I know Comp does DOHC stuff for Mustangs. I know they have major FI and NA grinds. It just seems there should be more to choose from. Porting heads, etc. is pretty easy but the cams should tie it the combo all together.

RicerSchnitzzle

To answer you.... Yes. JME gets 944 blanks from Germany and their custom billet cams are cheap in comparrison to our welded. They also have crazy 944 cam profiles for serious boost and NA applications. I talked to John in depth and he could not get blanks for 928's. Our only options are weld and grind or base circle reductions. Or both. Sucks but it's reality. John charges about $1350 for a pair of cams. 4v would be double that. Web cams is slightly cheaper at about $1150 a pair. Delta cams is cheapest with just a base circle reduction at $250 a pair, but no welding.

But the good news is a base circle reduction for about $125 a stick is cheap HP for most. You don't get as refined a result but the net is still better than stock in most cases.

As far as boost cams, looking to change duration and overlap, not too many options for us other than just turning up the boost some more.

One thing to remember, we are small in number and even smaller in agreement. For a company to make more 928 choices they might sell just a couple of each as we each have different ideas of what we want. Not worth the ROI to get blanks made IMO.

ptuomov

For FI S4 street motor, I can see a couple of practical options that would improve on S4 cams.

(1) GTS intake, S4 exhaust (cheap)
(2) GTS intake, S3 exhaust modified to fit S4 heads (if too small turbine or very restrictive turbo back exhaust.)
(3) S3 intake, S3 exhaust; both modified to fit S4 heads
(4) Elgin Cams 65-6 regrinds on S3 intake, S3 exhaust; both modified to fit S4 heads

If you read the mod ford 4.6L 4v dyno databases, the bigger cams add less absolute power on boosted motors than NA motors. In terms of percentage improvements, the boosted engine improvement is very small compared to NA improvement.

Caveat emptor is that I don't know much about cams, as many can attest... ;-)

Jon B.

I realize more than most that the SERIOUS performance 928 enthusiast is a TINY percentage of the overall populace. If you want to modify your 928 to the point where you are pushing the limits, you had better be willing to spend some money, and shed some blood, sweat and a LOT of tears.

I'm just wondering what has been/can be done in spite of this? Maybe I need to read through all of the search topics I find, or don't, because the only options I see with other cam grinds are the ones Carl has now. Also the older grinds which most big power guys use for NA builds which are the Devek cams. I mean, it seems that the only person who has gone WAY outside the box is Sterling with his Variocam setup. I don't pretend to have all the answers. But I think there has to be a better way for everyone to get a cam profile they need.

RicerSnitzzle, the prices you quote seem to be on par with the DOHC Mustang guys. I think a set of 4v Mustang cams runs over $2000. That includes the supporting head hardware though if I remember correctly.

ptuomov, I know that the gains are less OVERALL than maybe most think i'm looking at. But, generally, the numbers UNDER the curve are the most prevalent. I really like your ideas though, it's a good starting place.

Again, a good boost cam for my current car is just that. ONE camshaft. It's easy to do, and it costs about $420 for a REALLY solid performer that has proven into the 8 second quarter bracket.

It's hard to loose sight of the 928 dilemma with good cams and motor accessories with that ease of parts for most domestic cars. I really wish 928's had the aftermarket support my LSX has. It would truly be phenomenal.

RicerSchnitzzle

And boring..

I like the challange of doing things differently. Not just shopping for power out of a JEGS catalog. Makes it expensive sometimes, other times you have to be willing to McGuiver a little and have the purists throw up a little, Like putting a Nissan throttle body in my shark, or running MSD ignition with a MSD dizzy, or even giggle gas with meth and retard. Power can be had, but you have to step out of the box a little.

There's a NA 944 pushing 350RWHP out of half our engine. NO boost or spray. Just read the article at Barnes and Noble Friday in Excellence. Raetech's racer. Hell of a car, and most of what they have done is out of the box. But the argument should say, we could get close to twice that out of twice the displacement. I think they had a 4v 3.0L with big cams and custom intake, plus stand alone engine management. The power is there to be had.

Jon B.

No, no, I hear you. Although I can't get what I want out of a Jegs or Summit catalog. I do understand what you're talking about. Most of the big C5/C6 Corvette guys are internal shops. Not mail order catalogs. So, you have to pay for their R&D, which I would think should also be happening for the 928.

I'm more than willing to step out of the box, but I don't want an LSX swap to be that box. I don't see why we can't make twice that number on that 944. I was thinking about NA H/C LS1 motors today and wondering why a fully sorted 928 S4/GT/GTS motor couldn't match it. Other than talking displacement, which the 928 motors are lacking on a base LS1. 302/331, vs. 346., but still. A well sorted H/C LS1 can make over 470RWHP. NA! That's ONE camshaft, and supposedly inferior heads and intake.

I don't see any reason why they can't make the same kind of power with a little more help from someone with the money and time.

stuartph

Guys

I'd be up for a set of cams for a boosted car

ptuomov

The minimal stats that one would have to know when selecting a cam for a boosted engine are:
- Desired operating rpm range
- Average boost pressure in the operating rpm range
- Average exhaust manifold back pressure in the operating rpm range

Without knowing those three things, it's impossible to come up with any sort of semi-intelligent cam recommendation.

stuartph

Yes i agree with that, they will need thinking and input, i was just coming forward incase anyone else might be interested but as its an even smaller market the boost crowd i guess its a distant hope