One thing I am wondering with cams, and I have never done them on a roots supercharged car before, is when all components are added together, improved intake, cams, header and exhaust, will there be a drop in boost? It makes sense to me if there was a drop. The supercharger is set at a fixed rate, flowing X ammount of air per revoloution, this dose not change. If you improve the air flow into the engine and it flows more of it per revoloution, the supercharger still is moving air at that fixed rate. I may be pissing into the wind but I think boost levels accrost the board may drop a little with the stock pulley. Who knows I might be looking at this all wrong though.
Mabyee the Psi-Fi guys or someone with expeariance in this can chime in.
No drop in boost, that is what is nice about a blower, it is a positive displacement air pump, it will always pump the same until maximum efficiency is reached. The engine cannot flow any more or less that what the blower can, proportionately . The supercharger is set at a fixed rate, flowing X ammount of air per revolution, this does not change. If you improve the air flow into the engine and it flows more of it per revolution, the supercharger still is moving air at that fixed rate. You just answered yourself, but I feel you do not realize what it was you said. The supercharger is set at a fixed rate, flowing X ammount of air per revolution, this does not change.this is correctIf you improve the air flow into the engine and it flows more of it per revolution, the supercharger still is moving air at that fixed rateAnd this is correct, to a point and it is always proportional. Remember, you are NOT moving air THROUGH the engine, but INTO it. If you are moving X air at Y boost and free up the engine to run 1.5X air, it will still be at Y boost because the blower is always spinning at the same ratio to the engine, compressing the air to the same % boost into the closed engine. The air charge does not flow freely through the engine, it is stopped by a valve and gets compressed at the same rate each RPM that the engine is turning. A free-er exhaust will allow the boosted air to exit more quickly, but it will not affect the amount of boost because the valve separating the bigger exhaust was closed while the boost(compression) was being made, not allowing boost to bleed off. And conversely, a larger, free-er intake path WILL increase the level of boost UNTIL the maximum efficiency of the blower is reached, then it all remains the same.
My brain knows what I am trying to convey, I just hope it is making it to print so you can understand my thoughts.
Attached is a word doc that has a better explaination, but it is longer and I didn't want to take up too much bandwith within the thread.
you did i good job getting that to print, or at least i got it
Thanks, I wasn't sure because I edited it 4 to 5 times to streamline it and cut out redundancy and it was all blurring together to me. The most important point to remember is the fact that air does not flow THROUGH the engine, but into it. This is where a lot of people get tripped up when thinking about increasing flow. You can increase flow INTO an engine and you can increase frow OUT of an engine, but you cannot increase flow through an engine(the valves stop the flow).
OK Guys where are you getting all this info on these cam. I'm being lazy and not reading all this wonderful info. I'll post it up on my website in a short version.
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Rick
http://www.saturnionredline.com/
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Small Mods
Grill front and Rear, Xeon Lights, City Lights, Boost Gauge, Blue LEDS in DashGauges, Razi Spoiler, ColorStorm Typhon under car LED 16 million color lighting kits. Autometer Nexus Boost, Fuel pressure gauges.
Coming Soon
K&N Cold Air intake.
I see what you are saying,thanks for clearing that up, I had a long today and was looking into that a little too much. The reason I was thinking what I was is because I was under the impression that there was overlap and both the exhaust and intake sides were open at the same time for a brief moment.
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Brian
2004 Ion Redline....it's gone, traded for a Scooby.
1998 Taurus SHO...it's cool, sounds good and seats 5
I see what you are saying,thanks for clearing that up, I had a long today and was looking into that a little too much. The reason I was thinking what I was is because I was under the impression that there was overlap and both the exhaust and intake sides were open at the same time for a brief moment.
There is a small overlap of a few degrees, but this is not enough to bleed off significant poundage of boost.
OK Guys where are you getting all this info on these cam. I'm being lazy and not reading all this wonderful info. I'll post it up on my website in a short version.
I called CompCams and stayed on hold for around 25 minutes, this is what the Cam-tech siad the specs were. These were just released, so he said they were not "in the system", so they do not show up- even if you put the part # into the search box. I asked and he said that there was no advertised performance gains on his screen along with no recomendation for valve springs, it showed up as "N/A". So, until they get "into the system" there is no official word on how much HP they are supposed to make and as of this time, do not need springs other than stock.
THe part # for the set is 113250 (113251 & 252 for the individual cams) and the price is $479.63. They DO NOT have any in stock, it seems that they sold all of them already. Not to fear, the Cam-tech said that they had plenty of blanks and if an order was placed, they would grind a set ASAP.
Last edited by Blu_Redline; 04-23-2005 at 06:54 PM.
Yep, NADA quotes the Redline at 2590 dry, Yahoo and Kelley quote the Cobalt SS at 2990...400 lbs, or my oldest sister, on the money.
I don't see where NADA states the weights, but on the Saturn and Chevy websites, the curbweights for the RL and SS are pretty similar. RL is 2933 lbs while the SS is 2991 lbs. I know curb weight is different from dry weight, but comparing these two...we aren't really any lighter...even with our lighter body shell...sorry to burst people's bubbles on this.
Check out NADA, and do a value on your car - at the bottom right of the readout, its lists weight, along with a VIN model code, in some cases.
I noted that NADA JUST now listed the Cobalt in the 2005 section, and showed a weight for the SS of 2806 - NADA uses dry weights, the weights come from the manufacturer, so there's still a 216 lb weight difference - sorry to burst your bubble. Just messing.
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Just messing.
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