[rhudeboye]

<!--quoteo(post=72857:date=May 30 2009, 07:54 PM:name=Carl Fausett)-->QUOTE (Carl Fausett @ May 30 2009, 07:54 PM) <{POST_SNAPBACK}><!--quotec-->Here is the link to the video:

http://www.youtube.com/watch?v=nr1F_z8bi1I<!--QuoteEnd--><!--QuoteEEnd-->

Thanks for the video Carl. Do you have a goal for the horsepower you are looking to achieve?

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[firefish]

This reading is very interesting. Performance for sub 4k revs would, as flash said, be nice to have some info on - I for one rarely see north of 4k when simply moving my a.. from a to b. Unless provoked of course... [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]

Any chance of supplying software for V-Power fuel? There should be some gains there, especially with ignition management, whilst still being a perfectly streetable kit.

Looking forward to see the asking price...

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[Carl Fausett]

<!--quoteo-->QUOTE <!--quotec-->Do you have a goal for the horsepower you are looking to achieve?<!--QuoteEnd--><!--QuoteEEnd-->

No, thats not a good way to go about supercharger kit design.

Our design criterium were established at the beginning of the thread on this topic. They include simple installation, low cost, keeping the air conditioning, high reliability, etc.

When you assign some arbitrary number to a kit, then you must alter other items to make your abritrary number.

I wanted to avoid having everybody replace their injectors, for example. And so far, I have.

<i>Can</i> we replace the injectors, crank up the boost, and get more? Certainly. But this was supposed to be the Stage 1 kit, not Stage 2, so we have avoided doing that.

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[Carl Fausett]

I'm going to take the car back to the dyno tomorrow.

I want to get a dyno pull with the Variocam unplugged and see how it might differ.
Drives fine that way, seems a bit more linear and preictable, but the dyno will confirm or deny my assometer.

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[flash]

very fun stuff

please see if you can get readings down to a point at least below boost

love to see intake temps too

also, where is the pickup point for the lamda sensor? is this just a tailpipe reading for A/F?

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[rhudeboye]

<!--quoteo(post=72935:date=Jun 1 2009, 10:34 AM:name=Carl Fausett)-->QUOTE (Carl Fausett @ Jun 1 2009, 10:34 AM) <{POST_SNAPBACK}><!--quotec-->No, thats not a good way to go about supercharger kit design.

Our design criterium were established at the beginning of the thread on this topic. They include simple installation, low cost, keeping the air conditioning, high reliability, etc.<!--QuoteEnd--><!--QuoteEEnd-->

Yup, I went back and read it before posting. I was really surprised at the initial numbers as I thought they would be closer to 300 and therefore asked what you were expecting. Reading through all of the concerns and issues with stock parts as well as your over all goal of a direct bolt on helps me understand the approach better.

Looking forward to seeing what the finished product produces. More to the point what it adds over a chipped 968.

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[Carl Fausett]

<!--quoteo-->QUOTE <!--quotec-->More to the point what it adds over a chipped 968.<!--QuoteEnd--><!--QuoteEEnd-->

In the May issue of Excellence Magazine, they chipped a 968 and they got only 12 HP.

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[flash]

off topic, and not to detract from the potential of this project, but.....

they used the 3rd place "stage 1" chip in that test - there were 2 others that did better, but they were not a part of the article - also, we have seen these engines get a LOT more than that with other pretty simple stuff added in - very easy to get up over 265, and not too tough to get around 280

that's where it ends though without some very serious work

hence why this idea is so exciting

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[DiREW0LF]

Carl, when the kit is released please make sure it comes in a large enough box since my wife will be kicking me out and I'll need a place to live.

[img]style_emoticons/<#EMO_DIR#>/unsure.gif[/img]

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[DayDreamer]

<!--quoteo(post=73031:date=Jun 2 2009, 07:35 PM:name=DiREW0LF)-->QUOTE (DiREW0LF @ Jun 2 2009, 07:35 PM) <{POST_SNAPBACK}><!--quotec-->Carl, when the kit is released please make sure it comes in a large enough box since my wife will be kicking me out and I'll need a place to live.

[img]style_emoticons/<#EMO_DIR#>/unsure.gif[/img]<!--QuoteEnd--><!--QuoteEEnd-->
[img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img] [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img] [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img]

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[rhudeboye]

<!--quoteo(post=73015:date=Jun 2 2009, 07:10 AM:name=flash)-->QUOTE (flash @ Jun 2 2009, 07:10 AM) <{POST_SNAPBACK}><!--quotec-->we have seen these engines get a LOT more than that with other pretty simple stuff added in - very easy to get up over 265, and not too tough to get around 280

that's where it ends though without some very serious work
hence why this idea is so exciting<!--QuoteEnd--><!--QuoteEEnd-->

Quoted is above is my point and very much on topic. SC kits cost serious coin so what they produce would have to be greater then what the cheaper solutions produce. Not saying it wont, just wanted before and after numbers.

Just looking at the clip, the revs seem much faster. More then any chip, intake, exhaust and flywheel would do.

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[flash]

well, "off topic" depends on how you look at things - my comment was not about the kit - it was about things peripherally related to the kit

given that increasing power is inversely exponentially related to the cost involved, such comparisons are moot, and off topic - it will cost more than the kit to get the same power as the kit - it's not just the numbers though

also, i wanted to keep this conversation relative to the kit and its development, and not dive headlong into conversations about "what ifs" and such - of course we all know that we want to get our money's worth out of whatever it is, and so i get your point, but this is the problem with using peak numbers for comparisons

at this point, based entirely on what i've seen so far, and i could easily be missing something not disclosed yet, i'm guessing the kit will be about $2.5k-$3k (the blower is $1400, fan another $200, rising rate regulator is $180, and brackets, pulleys, and such probably about $400-$500)

yes, we can get 90% of the way normally aspirated to the "perfect" number of 300hp with the kit as it stands, for a bit over half what that kit is likely to cost - it's that last 10% that costs though - it's the same kind of thing as getting from 265 to 280 - that costs 5 times what it did to get from 240 to 265 - it would be another 5 times that expenditure to get from 280 to 300 - that's the nature of the beast - that's why this is so exciting

but as i said, this is all pretty much off topic - the big story is that this is supposed to be a simple bolt-on kit, with big power gains and no loss of features or reliability - this is very new news and nobody to date has gotten near this

if we can stay focused on what this kit is and does, i think we stand a much better chance of it getting to where we want than if we pick apart what is going on before it is done

i am treading a fine line myself, wanting to know more about the kit, without picking it apart - i also have very specific thoughts about what i have seen so far - i am having a hard time "waiting to see" - this is a discussion forum, and such conversations are at the heart of its purpose - however, i do not want to bash or discourage a new product, before it even complete

this one is still a good way off from being finished - there are components missing, and some that can obviously be improved on - i think we can wait a while to see what he comes up with before saying "that isn't worth it"

but regardless of how well it works, my fear in the end though is that we will run right back into what i did when considering the marketing - a couple of years ago i proposed the idea of a street legal 50 state smog legal kit that made 270 at the wheels for under $5k - after a year of working on it, i got a whopping 6 people that were serious - the reality is that there just aren't that many people with the cash for this - i throw money at this car like there is no tomorrow, and i am having a hard time spending this large of a lump on power i may never use - it still pulls at me, but i just don't know yet - i have a stack of things to consider about this

so, i totally understand the hesitance to dive further into development for an unknown market, and i commend and applaud carl for even trying - i hope he keeps going, and nails down all the things that would make it a no brainer for us

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[rhudeboye]

<!--quoteo(post=73073:date=Jun 2 2009, 04:13 PM:name=flash)-->QUOTE (flash @ Jun 2 2009, 04:13 PM) <{POST_SNAPBACK}><!--quotec-->- however, i do not want to bash or discourage a new product, before it even complete
- i think we can wait a while to see what he comes up with before saying "that isn't worth it"

but regardless of how well it works, my fear in the end though is that we will run right back into what i did when considering the marketing - a couple of years ago i proposed the idea of a street legal 50 state smog legal kit that made 270 at the wheels for under $5k - after a year of working on it, i got a whopping 6 people that were serious - the reality is that there just aren't that many people with the cash for this - i throw money at this car like there is no tomorrow, and i am having a hard time spending this large of a lump on power i may never use - it still pulls at me, but i just don't know yet - i have a stack of things to consider about this

so, i totally understand the hesitance to dive further into development for an unknown market, and i commend and applaud carl for even trying - i hope he keeps going, and nails down all the things that would make it a no brainer for us<!--QuoteEnd--><!--QuoteEEnd-->

No bashing or statements of its not worth it from me.

My problem is that I don't fully get the technical side. Carl's comments are all clearly understood and his page is informative, so Im learning. The kit in itself is, as you said, "exciting"! I need to continue to educate my self on this so I'm not so stuck on HP and 0-60. But its what I know and what counts to me.

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[flash]

no worries - lol - the conversations about stuff like this always goes there (remember the craziness about the chips?) - even i get caught up in it - it happens - we all start salivating at this stuff and the fervor begins to develop

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[Carl Fausett]

As promised, I went back to the dyno today to get you guys some answers.

We wanted to know if the supercharged performance would be better or worse with the Variocam active. It was worse. The Variocam performed well and added a little more HP and a lot more torque, and increased the usable HP under the curve.

As it was designed to do.

See charts below.

Then we wanted a before-and-after supercharging dyno chart. Rather than compare a "before" chart from a different day (with different temps, air density, hunmidity, and other variables) I removed the supercharger kit while the car was strapped down to the dyno. Took less than 30 minutes, and now you have a comparison of the same car on the same dyno on the same day - within an hour of each other.

Those that know how to read dyno charts know this already... so look away while I speak to the others.

You will be tempted to compare the Max HP before with the Max HP afterwards, and do the same to the torque readings.

To do your before-and-after comparison in this way is in error.

What you want to observe is all the usuable HP and Torque UNDER THE CURVE, that is: look at the total gain (shown as area under the curve) across all RPM ranges and then you can better understand the true performance gain we have just achieved.

Lastly: I have seen a comment or two about head gaskets. Honestly, you have no reason for concern at these boost levels. I have quite a bit of experience with your head gasket as the Porsche 928 and the 968 use the same one. I have supercharged more than 40 of these cars over the last 8 years. I suppose, when I think about it - that counts as 80-some head gaskets on the V8s.

At the 5 and 6 psi boost levels we run our Stage 1 kits at, we have never had a head gasket failure. Not one. We do know the ceiling for the stock 928 head gasket is about 12 psi of boost. North of that, you need to O-ring your heads, or use a steel composite head gasket. This kit is far from needing that. You can relax about head gaskets and this kit on your 968.

This little Guinea Pig will be coming apart tomorrow so we can use these prototype parts as patterns to make the production pieces. The kit is coming together nicely, (and the car is a blast to drive). I should be able to gather my costs of manufacture and put a number to it within 30 days.

Thank you for your interest,

Carl

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[flash]

a quick comment on head gaskets - they ARE an issue - they are beginning to disintegrate on STOCK engines - talk to pete about it - it's kind of scary - added pressure won't help those old ones

but, if you have a fresh one, i agree then those issues are most likely moot at this boost level - having done a few dozen low boost centrifugal units on other cars, i also never had head gasket problems as long as they were fresh

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[Carl Fausett]

I have supercharged 1978 and 1979 928's with stock head gaskets without a problem. Those gaskets are 30 years old.

Two years ago, I put a Stage 2 kit on my 1991 928 GT (8 pounds of boost) with 203,000 miles on the motor and stock head gaskets.... still driving it supercharged, over 210,000 miles on it now, no problems. 18 years on those head gaskets.

Now, If somebody has a) not maintained their cooling system correctly, allowed it to operate without anti-corrosive additives (a quality anti-freeze with additives is all that is needed) or uses high-lime content tap water and not distilled water - yes, they could have issues.

But to a stock engine that has been well maintained, no.

Early supercharging attempts by amateurs often reported head gasket problems. These were usually an attempt at finger-pointing away from a bad SC installation and blaming the failure on the head gasket. IMHO, it was detonation from a poor SC design and bad tune that did the head gasket in. Excessive combustion temps and/or detonation. These bad installs made it LOOK like the head gaskets woul not take boost without failing.

Properly tuned, well designed kits do not stress head gaskets unreasonably.

But, as you have mentioned, if the head gasket is already in poor condition for other reasons, thats a different story.

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[DiREW0LF]

Flash\Carl,

What effect would our current mods have on the gains from the SC'er kit?
Since the RSbarn kit changes the AF ratio from stock will it provide enough fuel in conjunction with the rr regulator?
Will the RSbarn catback or full exhaust have the proper flow, is the backpressure still required?

Carl,

Do you know what items will be added for the Stage 2? Obviously a different pully for more boost but is it going to require an intercooler? Injectors are probably on the list of additional parts?

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[rhudeboye]

Thanks for the charts. The gains look great. Cant believe you did this so quickly. I guess years in the biz has served you well.

I was also wondering how the SC will effect our current chip/exhaust mods. All most all of us here have them.

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[flash]

we're going to get off track here, and i didn't want to derail the thread about the kit, and i definitely do not want any of my comments to be misconstrued as criticisms - they are not

but yup - that is the problem - most of these cars have not been paid nearly as much attention to as they should have - again, talk to pete about this one - he sees more of these cars than anybody - he has been seeing these pop up with an alarming increase - he is also finding that they are falling apart when he takes the heads off for other reasons - it appears that it is a factor of age - it is only a short time before we start seeing them pop on a frequent basis - i'm actually considering changing mine as a precaution because i run the car so hard

comparisons to the 928 are all well and good to a point - but, the compression ratios never got to 11:1 - even the GTS was only 10.4 - the rest were lower - we all know that higher compression strains head gaskets more - most of these cars are still on their original gaskets - manufacturers of blowers will caution you against installation on an old engine - there are very real reasons for this - many moons ago i did a lot of paxtons, and they constantly sent around documentation on the dos and don'ts, specifically dictating NOT to install it, even at low boost, on engines with even lower compression than this, if they had more than 40k miles on them - with higher compression they had even more warnings - granted that the engines they were generally talking about were not as high of a build quality, but even doubling that number, you quickly run into the status of the bulk of these cars

on the subject of sharing head gaskets - i did some checking to follow a suspicion i had - as far as i can find, the 968 and 928 do not share head gaskets - it struck me as odd when you said it, since the bore is different, that they would have the same gasket, but i thought i'd check to be sure i wasn't nuts - the 928 may share the same gasket as the 2.5l 944 (though the part numbers are different), but the 944 and the 968 are totally different animals, as anybody who has played with the engine knows - there is really very little about the 968 engine that is common to the smaller 944 - we run into this problem all the time

anyway, none of this matters when talking about this kit - i'm not suggesting that this kit will CAUSE problems - all i am saying is that it may ACCELERATE already the eventuality of existing design and material problems that we are seeing pop up in stock engines

if you take the proper precautions, these are great, and such a kit can be VERY fun - fail to do that and you run the risk of getting the pleasure of enjoying the scintillating conversation of your local tow truck driver

i personally fully support the project, and want to do this or something like it on one of my own cars, but i also want to make sure it's rock solid before i do - the excitement level is high, and the eagerness to get it out there may tend to overrun prudence - we've already seen enough of that with other systems - we really want to see one that is thought out fully, tested completely, and just plain works on a daily basis - we can wait until that is done - it has already been this long, a few more months for some long term testing won't kill us

as for the questions others are asking about "what about this mod" and such, i think we need to wait until carl has this all worked out on a stock engine, before starting to think about what mods and such have what effects - he has already said he wants to wait until enough interest and sales in stage 1 can be generated before he can play with stage 2

carl - please continue on - if there is anything any of us can do to help, we are all more than happy to do it - this is one of the most exciting things we've heard about in quite a while

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