968 Supercharger Kit Development
#376
Three Wheelin'
The dyno plot is assuming 13% drivetrain loss. This is very low and I would expect that the actual losses would by closer to 17%, giving a before engine power of 225 bhp - yes still quite low - but that's dynos for you. The important thing is the % gain - 52%!!.
That's awesome. Can someone please donate their S2 to the cause - I need to get one of these kits. I'm afraid I'm a bit far away here in oz.
That's awesome. Can someone please donate their S2 to the cause - I need to get one of these kits. I'm afraid I'm a bit far away here in oz.
#377
Developer
Thread Starter
why does is say: "before at the engine: 215hp"
shouldn't that be 236hp???
shouldn't that be 236hp???
Rightly or wrongly - to do anything else would be to fudge numbers.
THIS 968 did 215 at the crank. Maybe the cat is a little restricted. Maybe the engine is a little short on compression. whatever.
The important thing is the trend - the improvement before and after. You can relate that to your engine, which, if it is in better condition than this one will do similarly albeit in a higher range.
The dyno plot is assuming 13% drivetrain loss.
Again, the actual number achieved is less important compared to gain before-and-after.
Same car, measured on the same dyno the same way. Before and After comparison is as accurate as we can make it.
#378
Instructor
Carl...what are your thoughts for those who already have a chip?? will this negatively affect the kit performance??? will it help??? will use of the stock chip be required to run your kit?
Thanks,
Thanks,
#379
Developer
Thread Starter
It depends on the chip. Not all chips are the same, some do more than others. If it's one of the "we'll raise your redline 200 rpm" type chips, it wont make a hill of beans difference. If its a GOOD chip, and it also nudged up your ignition advance curve, it probably enriched your mixture a little bit too. And thats a good thing.
After you install the SC kit, you are encouraged to go to a chassis dyno for a final tweak and tune of the SC fueling (we have two easy adjustments on the FMU). At that time, the dyno operator will be able to see detonation or not... or you could even pull the chip and put the OEM one back in for a test.
Keep the one that works best. Either way, I expect you to be fine.
After you install the SC kit, you are encouraged to go to a chassis dyno for a final tweak and tune of the SC fueling (we have two easy adjustments on the FMU). At that time, the dyno operator will be able to see detonation or not... or you could even pull the chip and put the OEM one back in for a test.
Keep the one that works best. Either way, I expect you to be fine.
#380
Team Owner
Join Date: Oct 2009
Location: one thousand, five hundred miles north of Ft. Lauderdale for the summer.
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why would anyone be surprised at the 215 hp estimate ?... add the miles and what that will do to the cat and expect to see exactly what Carl got on the dyno.
Carl's kit can make 70 - 110 hp !
lose the cat, add the new injectors and you are talking about 340 hp.
Carl's kit can make 70 - 110 hp !
lose the cat, add the new injectors and you are talking about 340 hp.
#381
Track Day
Karl,
Looking forward to Spring even more now. I'll be purchasing your SC and from looking at your install instructions, believe I can do this install myself.
As regards the injectors: is there a specific model I need to purchase and are they hard to install?
Got the desire and aptitude--just not a whole lot of experience
Like others have said, "Great work! To bring this to market in such a short time is phenomenal!"
Looking forward to Spring even more now. I'll be purchasing your SC and from looking at your install instructions, believe I can do this install myself.
As regards the injectors: is there a specific model I need to purchase and are they hard to install?
Got the desire and aptitude--just not a whole lot of experience
Like others have said, "Great work! To bring this to market in such a short time is phenomenal!"
#382
Developer
Thread Starter
At the moment, I am holding the injector specs close to my chest. I'd rather you buy them from us.
I can provide them prior to installing the supercharger for $300 per set of 4.
Then, when you oprder the SC kit, just order the Stage 1 kit and remind us that you have the Stage 2 injectors installed. I will ship your Stage 1 kit with a Stage 2 pulley.
I can provide them prior to installing the supercharger for $300 per set of 4.
Then, when you oprder the SC kit, just order the Stage 1 kit and remind us that you have the Stage 2 injectors installed. I will ship your Stage 1 kit with a Stage 2 pulley.
#386
Rennlist Member
At the moment, I am holding the injector specs close to my chest. I'd rather you buy them from us.
I can provide them prior to installing the supercharger for $300 per set of 4.
Then, when you oprder the SC kit, just order the Stage 1 kit and remind us that you have the Stage 2 injectors installed. I will ship your Stage 1 kit with a Stage 2 pulley.
I can provide them prior to installing the supercharger for $300 per set of 4.
Then, when you oprder the SC kit, just order the Stage 1 kit and remind us that you have the Stage 2 injectors installed. I will ship your Stage 1 kit with a Stage 2 pulley.
I support your decision 100%. No reason why you should be sharing your trade secrets. You are doing this to make a living, not to end up on welfare.
Good luck.
Raj
#387
Developer
Thread Starter
These are considered 40#/hr injectors, where the OEM injectors are listed as 36#/hr.
As mentioned before - thats not the difference that matters in this case. What matters is the
cycle times have been greatly improved since the first generation injectors (OEM) were made.
These new Bosch injectors cycle much faster (respond quicker) so a garden-hose sized injector is no longer needed to get the job done. Keeping the size and impedence correct keeps the on-board LH computer happy with no chip changes.
The difference was dramatic - you may have seen our Stage 1 and Stage 2 charts from the same car.
You KNOW that much improvement was not because of 4 more pounds per hour of fuel. It was the accuracy and speed of the injector cycles.
As mentioned before - thats not the difference that matters in this case. What matters is the
cycle times have been greatly improved since the first generation injectors (OEM) were made.
These new Bosch injectors cycle much faster (respond quicker) so a garden-hose sized injector is no longer needed to get the job done. Keeping the size and impedence correct keeps the on-board LH computer happy with no chip changes.
The difference was dramatic - you may have seen our Stage 1 and Stage 2 charts from the same car.
You KNOW that much improvement was not because of 4 more pounds per hour of fuel. It was the accuracy and speed of the injector cycles.
#388
Team Owner
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Raj,
thank you for that post.
thanks for all the help as well,
Carl... saw your Stage 2 kit on ebay... fair price and to all who will be installing it -- go the spoils.
thank you for that post.
thanks for all the help as well,
Carl... saw your Stage 2 kit on ebay... fair price and to all who will be installing it -- go the spoils.
#389
Racer
Just a thought, Carl: if you don't sell enough complete kits to make this project worth your while, you could sell a DIY'er special consisting of proprietary components such as a set of plans, a parts list, and the brackets you've fabricated. Let the customer take it from there.
As a reseller of all the parts, you're necessarily seeking a return on your investment in them, whereas a savvy buyer would probably prefer to shop for the best deals on things like the supercharger, belts, hoses, nuts & bolts, etc.
I mean this to be completely uncritical, as I have nothing but praise for your efforts and knowledge.
However, the idea of a "fair price" is subject to the realities of the market (I finished an undergrad degree in economics, but only took a degree in international studies). Something is worth what someone is willing to pay. Simple as that.
It's not a case of "buyer beware"; rather, it's a case of "whatever the market will bear."
As a reseller of all the parts, you're necessarily seeking a return on your investment in them, whereas a savvy buyer would probably prefer to shop for the best deals on things like the supercharger, belts, hoses, nuts & bolts, etc.
I mean this to be completely uncritical, as I have nothing but praise for your efforts and knowledge.
However, the idea of a "fair price" is subject to the realities of the market (I finished an undergrad degree in economics, but only took a degree in international studies). Something is worth what someone is willing to pay. Simple as that.
It's not a case of "buyer beware"; rather, it's a case of "whatever the market will bear."
#390
Track Day
Join Date: Nov 2009
Location: Bragg Creek, Alberta
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That's a bit of an over-simplification. Standard items like books are cheap through the internet because a given book is the same whether you buy it from Amazon or Indigo. There's considerable difference in metallurgy in nuts and bolts, and in the specification of hoses. I see a lot of value in having someone with experience putting together a complete package of parts that will do a complex job correctly and reliably. And for a business-owner, selling incomplete kits is liable to lead to bad experiences for buyers, and to a loss of credibility among the business-owner's prospective customers.
Mark
93 968 coupe, oak green
Mark
93 968 coupe, oak green