Welcome Carl.
Well, it’s great to see you here on this forum and to hear of your intentions of developing a supercharger kit for our cars. As an owner of a supercharged 968, I would definitely like to offer whatever help I can. It’s funny, but I have come close to giving you a call many times, seeking some supercharger advice for myself. I know you have spoken with Flash and assume that he brought you up to date on the trials and tribulations of my cars supercharger setup. If not, I would be more than happy to speak with you and answer any questions you might have.
Jeff
I don't know too much about the instricasies of supercharging, but I've been wondering about something - in general, how does supercharging an engine impact other potential mods? By that I mean, is it likely that it would still be beneficial to install headers on a supercharged engine? What about the type of chip needed? And what about head work? I'm asking because I've been planning to install the RS Barn header/cat back, and also do at least the stage 2 head rebuild and purchase a stage 2 chip to go along with it, but if a well-executed supercharger negates the benefits of these mods, this would represent some money saved toward the purchase of the supercharger (not that I want to take business away from RS Barn, whom I respect greatly). Thanks.
Other the than the chip, these mods will help get the most out of the supercharger.
I agree with PorscheDude. The mods you are considering are a great way to go, as they will give some immediate gains that you can enjoy now, while waiting or saving for a supercharger kit. I haven't done any head work or cams or headers yet, because my car was a prototype for a kit, and we wanted to keep it as stock as possible. It does have a custom exhaust which I HATE! Oh it sounds horrible and will be replaced when I can afford it. In fact, at this point, I would like to take my car a few steps backwards and not only change the exhaust, but also delete the intercooler and the thicker head gasket (lowered compression), and reinstall the stock ecu, just to get it back closer to stock. Some of these changes were made because the experts mis-diagnosed some of the issues my car was experiencing. Not that I am blaming them, this isn't an exact science and there is definitely a lot of trial and error to be had, and I knew that going in.
Anyways, except for the chip (which actually may work as well--not sure), I would add all those mods to my car as well down the road, most likely.
So I say "Go for it!" [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]
Carl,
We developed a centrifugal supercharger system about 5 or 6 years ago for these cars. Nowadays we use a Procharger C2 unit and I am sure you are aware of how compact it is.Good luck using a centrifugal and keeping the A/C.The reality is that if you can do it, you will have to give up the power steering. There is no room for the SC, alternator,A/C, power steering and keep the stock intake manifold.No way, no how, not if you want to keep it at $5-6k.
What about if it were mounted on the driver side of the engine back where a turbo would be mounted and use an extended shaft to get the pully to the front of the engine? A long shaft like that is used on many of the supercharger designs on corvette (although for a different reason and different type of charger).
Or an even more insane thought...any way to run it off the rear of the balance shaft?
The intake manifold is pretty deep, there is not alot of room for a charger and piping.
Still a great idea.
<!--quoteo(post=69655:date=Mar 31 2009, 01:25 AM:name=SpeedForceRacing)-->QUOTE (SpeedForceRacing @ Mar 31 2009, 01:25 AM)
<{POST_SNAPBACK}><!--quotec-->No way, no how, not if you want to keep it at $5-6k.<!--QuoteEnd--><!--QuoteEEnd-->
I agree with SFR, and it also seems to me that Mr. Fausset is giving himself to reinventing the wheel. The 928 has much more waggle room in the engine bay than does a 968. A 968's engine compartment is so tight that a centrifugal SC is optimally placed where the AC compressor is.
Now, I've driven a 968 on the road without power steering. It's really not that bad. So I would find it preferable to surrender the PS pump and retain the AC, if it were for a daily driver.
However, once again, the 968's engine poses a very different problem because the PS pump is attached to a balance shaft cover, and the balance shaft cover itself is (1) line-honed to perfectly fit the engine block, (2) actually fabricated to contain part of the bracketing for the PS pump, and (3) not particularly sturdy for purpose of building a bracket around it. A supercharger requires a much stouter mount than does a PS pump.
I've also seen a SFR setup on a 968 track car last summer at Mid-Ohio (can't remember the owner's name, but it was a black car), and I really liked what I saw.
any real news on this yet? i'm dying to see somebody figure out how to cram a unit in there without sacrificing the ps or ac and also cram in the necessary user serviceable air cleaner - one of the big problems we ran into, and shortcomings of a lot of kits, was the minimum surface area of 120 sq inches (needed for 5 psi - more for higher boost) - less than that resulted in reduced efficiency which seemed silly - can't get it out if you can't get it in
it's a tough job, but i'm more than hopeful - i know it can be done, but the intake manifold made the throttle body location a problem - the dual resonant effect of the factory manifold, which is unique to the 968, also plays a big role in programming - also the new upcoming emissions laws made some of the changes tougher to get by
that's the whole reason we tabled the idea - the cost to develop, given the 6 people who we actually believed when they said they were "interested" just didn't make sense - we weren't looking for anybody's money up front, but only a real commitment if and when we made it happen - not many were serious - we see plenty of people who "say" they would be interested, but many of those same people are reluctant to buy new tires when they need them - another issue was that in the end many wanted big turbo power, and not what a low boost centrifugal unit produces - it's not like you can bump it up much either - that pretty much chased us away
at this point, while i still would be willing to get one, even i have issues - it must be able to pass 50 state emissions tests, which will be all states in 2010, and given that i have dumped over 70k into this car in the last 6 years (counting the 28.5 to purchase), just to handle the power i have now, another 5k is something to consider carefully - i'm getting dangerously close to ferrari territory
i love this car, and 300hp would be great, but even i have to wonder when enough is enough
lol - but, i could change my mind tomorrow and dive in feet first
If you dive in, I'll be ready with a towel. Your goals would fit mine perfectly, so I hope I counted as one of the "truly serious" candidates.
From Rennlist
<!--QuoteBegin-Carl Fausett;6508512+-->QUOTE (Carl Fausett;6508512)<!--QuoteEBegin-->At the moment, we are driving the supercharger off the crank with the existing crank pulley.
That saves $$ manufacturing a special crank pulley, and makes installation easier for all involved.
The plan is to supply a new serpentine belt to wrap around the accesories (AC and Alternator) and now the new SC head as well. The rpm ranges the accesories operate in will not be effected. They will run just as before.
Please consider this is the design of the moment.... we go through many iterations before we go to production on the last best solution, so it may change again. But this is the best (and pretty promising) location and drive belt arrangement that we have working at the moment.<!--QuoteEnd--><!--QuoteEEnd-->
yeah - that part was pretty much a given, and the way i planned to do it too - that's the way it works on the roots system too - it does present a tensioning problem though - the aircleaner was possibly the biggest problem, and with the unit i wanted to use, the clocking presented a problem with two things occupying the same space, requiring a manifold change, which made it all too expensive
waiting to see how this works out - love to see somebody finally get there
Time to give you guys an update.
The supercharged 968 is running... obviously everything is mounted in their final locations and plumbed.
We were able to keep the air conditioning, alternator, and power steering in their stock positions.
We are not quite finished yet, I have not found an air filter or a set of radiator fans I like yet.... but having fitted a couple now I think we are really close. The next version of air filter and radiator fans will be here in 2 days and I will have them mounted up.
Here are some pictures to show you where we are at for the moment.
When I design a supercharger kit, I like to keep them very clean and elegant. Not a lot of plumbing and tubing running every-which way. I hope you like it.
I have been advised that the AC belt tensioner turnbuckle likes to fail on the 968. Of course, as we are using that to tighten the belt for us with this kit, that will be something we may need to address. Do we know that the rod end fails on its own - or is it a function of the mechanic not loosening the pivot bolts while they attempt to tighten the belt?
I hope to drive it Thursday.
Then the tuning can begin in earnest.
<b>Here is the remaining process: </b>IF there are no leaks and the system performs well, and IF I do not have to install larger injectors (thats a lot of ifs), then we will post dyno numbers. Then we disassemble the parts from the car taking photographs as we go to use in the installation manual.
Our installation manuals are very comprehensive - you are welcomed to download and review any of them that you wish from this link to see how thorough we are:
http://www.928motorsports.com/install.html
With the parts out of the car, we can start to model production parts from these prototype pieces.
That will get me my final cost of the kit (the cost to manufacture the parts we have hand-made so far).
BE SURE TO SCROLL TO THE RIGHT TO SEE BOTH PICTURES
looking good - this is promising
generally it's the ear on the AC compressor that fails, though the turnbuckle itself has been known to fail too - the cause is likely the failure of the person wrenching to release the load on the items mounted before adjusting the turnbuckle, and/or failing to tighten them back up afterward
question: it looks like there is ample room to lay a big cone filter in there - of course an airbox would have to be made to separate it from the engine bay, but this would make service a lot easier - have you tried that? - i ask because, having already played with this one, the area behind the bumper cover is a less than desirable location for the air cleaner, for both reasons of heat and dirt - it's a good 30 degrees cooler at the entrance of the stock airbox than it is down at the stock pickup point, which is also danged hard to get to in order to clean it as often as it should be (or have you figure out how to do that?)
keep up the good work - looking forward to the results - i know how hard it is, and finally just gave up thinking about it - glad to see somebody else picking up the baton
This is exciting. Kind of makes talk of engine swaps and the like passe. It's amazing how quickly you have pulled this together.
Please do not forget about the European market when designing this kit. I don't know what the differences are between US and ROW cars (save for some design features and the blink test function) but a kit for like 5 grand should be perfectley sellable over here too. I would definately consider it, if available for my CS, if I where to up the hp (which I am in the future). A lot of people over here race their 968's and many spend a lot of money to gain only some 25 hp. If this kit you are developing will produce power in the neighbourhood of 300 hp I reckon they shouldn't be too hard to sell.
My .02
Good luck,
Magnus
Thank you for your interest.
I would not dare forget about the European market (we ship our 928 and Ferrari SC kits all over the world) and this will be no different.
But - as I do not have a ROW 968, I will depend on you guys to tell me what the salient differences are.
More superchargers! More superchargers! More superchargers! Ya!
Hey, this is great news, Carl. That was quick. I guess you guys really put your mind to it.
Question for ya--Are you planning on running with the stock ecu or have you got something else in mind? When I bought my supercharged car, the previous owner was using a LINK system that piggy-backed on the ecu to adjust the fuel map. That seemed to work alright, but the next shop I had my car at talked me into going stand alone, and unfortunately, I was too naive to know better. Cha-ching for them. Oh well. To make matters worse, they installed a unit that the uses a map sensor instead of a maf sensor, so tuning it to run at idle and when cold has been a challenge. I'd love to yank it out and put the stock ecu back in. I really hope to hear that you are successful using the stock components.
Just came back from the first drive on the 968 SC. We had air/fuel gauge and vacuum/boost gauge in the car, and two of us went out to long rural road with hill.
We had a "base tune" in it that must've been close - it fueled pretty well, then with only one stop to adjust the FMU a little more, we had enough fuel to bounce off the rev limiter. Pulls hard and strong.
Some particulars: gauges showed about 1 PSI of boost at 2,000 rpm. Boost climbed very quickly and we had 6 psi at 4500 rpm and held that to redline. Coolant temperature gauge remained steady at the stock spot, not problem. Alternator charging normally also. Engine idles normally right where it was before supercharging.
We did about 10 "pulls" on the hill in 2nd, 3rd, and 4th gears. The system was able to fuel to redline in each gear without a problem. Never went lean. The boost was very driveable because it was always "in" after 2,000 rpm. It was just a quiet steady push into the seat throughout the whole powerband. The only thing you could barely hear was a gentle whistle from the supercharger. Not bad at all.
I am scheduling time at the dyno now to get you some numbers.
I hope it comes with a drool bucket, I'm gonna need one [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img]
Ooopps too late