Calling Skip/Others: Cam Questions - A little help?
04-08-2004, 12:04 PM
#16
Race Director
Originally posted by david fracolli
If you think compression has nothing to do with cam selection then you need to go back and take a basic engine building course! Compression has everything to with cam selection.
If you think compression has nothing to do with cam selection then you need to go back and take a basic engine building course! Compression has everything to with cam selection.
Originally posted by david fracolli
There is no way in the world that I would run a 230 degree lift cam at 0.050 inch lift with 9 to 1 compression. Just like a would not run a 210 degree cam with 11.0 to 1 compression.
There is no way in the world that I would run a 230 degree lift cam at 0.050 inch lift with 9 to 1 compression. Just like a would not run a 210 degree cam with 11.0 to 1 compression.
Originally posted by david fracolli
The reason there is zero development is because a cam by itself is not going to do much. If you don't believe go ask any engine builder. To get power out of an N/A engine requires a proper balance between camshaft design, compression, valve size and port size and shape.
The reason there is zero development is because a cam by itself is not going to do much. If you don't believe go ask any engine builder. To get power out of an N/A engine requires a proper balance between camshaft design, compression, valve size and port size and shape.
To say a cam by itself will do nothing is wrong. As with most things, that depends. But don't say a cam by itself will do little. That's an absolute statement that is simply not true.
From the JME web site:
"Performance Hydraulic
S3-14 for 944/928Best power band 3600-6500 rpm. 900 rpm idle. .474 cam lift (In & Ex) with stock base circles for drop in performance. Uses stock or 944 Turbo valve springs for best results 12-18 bhp over stock camshaft with stock exhaust. Needs stock (37 psi.) fuel system pressure with Motronic at click 1. Tested against all comparable competitors camshafts and proven better."
Name one mod for a 8v NA 944 engine that will produce that sort of power. The power band is pretty reasonable for a performance street car.
04-08-2004, 12:21 PM
#17
Race Director
Geo...
When making my statments about Cams I had the Milledge ones in mind. I have look at his website and he has a few I guess would be "standard" grinds. Each can get more and more power, he also states that they move power up in RPM band.
Jon Milledge Cams... Link to Website
So looking at his specs it looks like S3-14 is the best cam for a street car.
Power band is 3600-6500 with 900 RPM idle. He quotes 12-18 hp with stock exhaust. I'd expect the 12-18 hp to be at 6000 to 6300 rpm and have no idea how much is gained at 3600 RPM my guess is not 12 hp. For me in street driving I rarely go past 4k.
All the rest of his cams seem geared torward higher RPM use and need other engine/fuel system work to see all the gains.
I don't know he has any "custom" grinds beyond what he stated above. I'd expect if you had custom race motor he could figure the right grind to optimize what you have and where you want the power. I also expect that to cost more than $650.
When making my statments about Cams I had the Milledge ones in mind. I have look at his website and he has a few I guess would be "standard" grinds. Each can get more and more power, he also states that they move power up in RPM band.
Jon Milledge Cams... Link to Website
Normally Aspirated
Performance Hydraulic
S3-14 for 944/928Best power band 3600-6500 rpm. 900 rpm idle. .474 cam lift (In & Ex) with stock base circles for drop in performance. Uses stock or 944 Turbo valve springs for best results 12-18 bhp over stock camshaft with stock exhaust. Needs stock (37 psi.) fuel system pressure with Motronic at click 1. Tested against all comparable competitors camshafts and proven better.
PH 277-14 for 944/928
Best power band 4000-6600 rpm. 900 rpm idle. .474 cam lift (In & Ex) with stock base circles for drop in performance. Uses stock or 944 Turbo valve springs for best results. Motronic chip must have rev limit raised for best results. 14-20 bhp over stock camshaft with non-stock exhaust. Needs stock (37 psi.) fuel system pressure with Motronic at click 1. Tested against all competitors camshafts and proven better. None were comparable.
RH CS-14 for 944
Best power band 4200-6800 rpm. 1000 rpm idle. Off idle lope. .474 cam lift (In & Ex) with stock base circles for drop in performance. Uses stock or 944 Turbo valve springs for best results. Motronic chip must have rev limit raised for best results. 16-24 bhp over stock camshaft with race exhaust. Needs custom Motronic chip or aftermarket engine management. No equivalent competitors cam. Used where lift is restricted to stock but racing cam is allowed.
P/RH 8SR-14 for 944 performance/928 race
Best power band 4000-6900 rpm. 1000 rpm idle. .503 cam lift (In & Ex) with near stock base circles. Uses 944 Turbo or race valve springs (recommended) for best results. Motronic chip must have rev limit raised for best results. 25+ bhp over stock camshaft with race exhaust. Needs custom Motronic chip or aftermarket engine management. No equivalent competitors cam. Used where lift is un-restricted but racing cam is allowed.
RH B13-10, B13-14 for 944 race/928 race
Best power band 4400-7200 rpm. 1100 rpm idle. Off idle lope. .539 cam lift (In & Ex). Modified hydraulic lifters required. Race valve spring & retainer package required. Motronic will not work. Bhp available depends upon tune of engine. No equivalent competitors cam. Used where lift is un-restricted but racing cam is allowed. RH B13-10 has better midrange power, RH B13-14 has better top end power.
Race Solid Lifter RS 304M2/280M-10 for 944/928
Best power band 5000-8200 rpm. 1300 rpm idle. Off idle lope. .595 cam lift In, .510 Ex. Race solid lifter, valve spring & retainer package required. Motronic will not work. After market engine management only. Bhp available depends upon tune of engine. No equivalent competitors cam. Used where lift is un-restricted but racing cam is allowed. Best results with unrestricted intake, fully ported cylinder head with larger valves, racing header.
Performance Hydraulic
S3-14 for 944/928Best power band 3600-6500 rpm. 900 rpm idle. .474 cam lift (In & Ex) with stock base circles for drop in performance. Uses stock or 944 Turbo valve springs for best results 12-18 bhp over stock camshaft with stock exhaust. Needs stock (37 psi.) fuel system pressure with Motronic at click 1. Tested against all comparable competitors camshafts and proven better.
PH 277-14 for 944/928
Best power band 4000-6600 rpm. 900 rpm idle. .474 cam lift (In & Ex) with stock base circles for drop in performance. Uses stock or 944 Turbo valve springs for best results. Motronic chip must have rev limit raised for best results. 14-20 bhp over stock camshaft with non-stock exhaust. Needs stock (37 psi.) fuel system pressure with Motronic at click 1. Tested against all competitors camshafts and proven better. None were comparable.
RH CS-14 for 944
Best power band 4200-6800 rpm. 1000 rpm idle. Off idle lope. .474 cam lift (In & Ex) with stock base circles for drop in performance. Uses stock or 944 Turbo valve springs for best results. Motronic chip must have rev limit raised for best results. 16-24 bhp over stock camshaft with race exhaust. Needs custom Motronic chip or aftermarket engine management. No equivalent competitors cam. Used where lift is restricted to stock but racing cam is allowed.
P/RH 8SR-14 for 944 performance/928 race
Best power band 4000-6900 rpm. 1000 rpm idle. .503 cam lift (In & Ex) with near stock base circles. Uses 944 Turbo or race valve springs (recommended) for best results. Motronic chip must have rev limit raised for best results. 25+ bhp over stock camshaft with race exhaust. Needs custom Motronic chip or aftermarket engine management. No equivalent competitors cam. Used where lift is un-restricted but racing cam is allowed.
RH B13-10, B13-14 for 944 race/928 race
Best power band 4400-7200 rpm. 1100 rpm idle. Off idle lope. .539 cam lift (In & Ex). Modified hydraulic lifters required. Race valve spring & retainer package required. Motronic will not work. Bhp available depends upon tune of engine. No equivalent competitors cam. Used where lift is un-restricted but racing cam is allowed. RH B13-10 has better midrange power, RH B13-14 has better top end power.
Race Solid Lifter RS 304M2/280M-10 for 944/928
Best power band 5000-8200 rpm. 1300 rpm idle. Off idle lope. .595 cam lift In, .510 Ex. Race solid lifter, valve spring & retainer package required. Motronic will not work. After market engine management only. Bhp available depends upon tune of engine. No equivalent competitors cam. Used where lift is un-restricted but racing cam is allowed. Best results with unrestricted intake, fully ported cylinder head with larger valves, racing header.
Power band is 3600-6500 with 900 RPM idle. He quotes 12-18 hp with stock exhaust. I'd expect the 12-18 hp to be at 6000 to 6300 rpm and have no idea how much is gained at 3600 RPM my guess is not 12 hp. For me in street driving I rarely go past 4k.
All the rest of his cams seem geared torward higher RPM use and need other engine/fuel system work to see all the gains.
I don't know he has any "custom" grinds beyond what he stated above. I'd expect if you had custom race motor he could figure the right grind to optimize what you have and where you want the power. I also expect that to cost more than $650.
04-08-2004, 12:27 PM
#18
Addict
Rennlist Member
Rennlist Member
I'm running a JME cam in my car. Noticable after 3k RPM. Here is some information from Jon:
I also thought the list might find the following to be of value:
At the end of the day, the JME cam upgrade is expensive any way you look at it (when compared to a reground cam). While the increase is noticable, it it not that noticable. Personally, I would not do it again.
Driveability is great. Even better with a small compression increase. We can machine your head for $180 to increase the compression. What you want is a responsive torque-ier engine that rev's freely, pulling strongly to the rev limit. Cam is $650 ground on a new chilled iron billet made for us in Germany.
It is not a regrind. This means that you have no lifter oil feed problems, no
lifter travel problems and no small base circles to cause premature cam wear. We can supply springs and our titanium retainers. Springs are $28/pair of inner and outer, Ti retainers custom made for us by DelWest are $27 ea. Our dyno developed Serdi Comp valve job is $400.
What header are you running. We have one that works better than any of the mass marketed ones. It's $650 also.
It is not a regrind. This means that you have no lifter oil feed problems, no
lifter travel problems and no small base circles to cause premature cam wear. We can supply springs and our titanium retainers. Springs are $28/pair of inner and outer, Ti retainers custom made for us by DelWest are $27 ea. Our dyno developed Serdi Comp valve job is $400.
What header are you running. We have one that works better than any of the mass marketed ones. It's $650 also.
I also thought the list might find the following to be of value:
K& N installations usually end up breathing heated air that went through the radiator. This causes a power loss of more than 3% per 10 deg.. C. For that reason, we don't recommend the cone filter. On our $120K DTS dynamometer, we tested all available filters and found that the K&N filter insert in the stock box is best if the tube from the fender is
removed and replaced with a 3" smooth bore tube from the fender. This gives the coolest possible air with the least restriction.
removed and replaced with a 3" smooth bore tube from the fender. This gives the coolest possible air with the least restriction.
At the end of the day, the JME cam upgrade is expensive any way you look at it (when compared to a reground cam). While the increase is noticable, it it not that noticable. Personally, I would not do it again.
04-08-2004, 12:55 PM
#19
Race Director
Originally posted by Ken D
At the end of the day, the JME cam upgrade is expensive any way you look at it (when compared to a reground cam). While the increase is noticable, it it not that noticable. Personally, I would not do it again.
At the end of the day, the JME cam upgrade is expensive any way you look at it (when compared to a reground cam). While the increase is noticable, it it not that noticable. Personally, I would not do it again.
Also, regarding not being that noticable..... Butt dynos are notoriously inaccurate. Some people claim to feel 2 hp gains while others can barely feel a 20 hp gain. What I find impressive is that you can actually feel the gain as low as 3000 rpm.
Me, I'll probably end up buying his $650 header. I'll be making a custom CAI with a good AFM adapter that I'm going to have to design on CAD myself. I wish I could run a cam.
I'll bet a JME cam, header, and really good CAI would wake up the 8v 944. It's really too bad that the base timing is not user adjustable. I have personally witnessed one car make 7 hp on a Dynojet just by playing with the timing, although 1-3 hp is more normal.
04-08-2004, 01:02 PM
#20
Three Wheelin'
That was the point that I was trying to get across. Look at the specs for s3-14 cam. Power band 3600 to 6500 RPM. How many people running daily drivers are going to run there car in this range? In very basic terms all a cam is going to do is move the torque curve up or down the rpm range.
Now I can't speak for everyone that drives a 944N/A but I am willing to bet the the vast majority are not going to sacrifice low rpm torque for higher rpm horsepower.
Will a replacement cam make more horsepower..........yes
Is it worth it................. In my own opinion NO
Sure, if you design a complete package it will outperform individually selected components thrown together. But to say a cam by itself will do very little is horsepucky. I know of cams that will produce 16 + hp on totally stock engines. Dyno proven. Actually, I know of cams for the same car that with special valve springs (barely heavier than stock, but made from a special material with better harmonics) that will add 20+ hp. And this is on an engine with similar stock hp as the 8v 944.
I can show you thousands of dyno sheets from other engines but show me one dyno sheet from a stock 944NA that shows a 16hp increase with no loss of torque below 3200rpms.
I would love to see the dyno sheet from a 944N/A with one of John's cams installed. Why is that no vendor will ever post Dyno sheets? Kinda makes you wonder.
Now I can't speak for everyone that drives a 944N/A but I am willing to bet the the vast majority are not going to sacrifice low rpm torque for higher rpm horsepower.
Will a replacement cam make more horsepower..........yes
Is it worth it................. In my own opinion NO
Sure, if you design a complete package it will outperform individually selected components thrown together. But to say a cam by itself will do very little is horsepucky. I know of cams that will produce 16 + hp on totally stock engines. Dyno proven. Actually, I know of cams for the same car that with special valve springs (barely heavier than stock, but made from a special material with better harmonics) that will add 20+ hp. And this is on an engine with similar stock hp as the 8v 944.
I can show you thousands of dyno sheets from other engines but show me one dyno sheet from a stock 944NA that shows a 16hp increase with no loss of torque below 3200rpms.
I would love to see the dyno sheet from a 944N/A with one of John's cams installed. Why is that no vendor will ever post Dyno sheets? Kinda makes you wonder.
04-08-2004, 01:06 PM
#21
Addict
Rennlist Member
Rennlist Member
Originally posted by Geo
Also, regarding not being that noticable..... Butt dynos are notoriously inaccurate. Some people claim to feel 2 hp gains while others can barely feel a 20 hp gain. What I find impressive is that you can actually feel the gain as low as 3000 rpm.
Also, regarding not being that noticable..... Butt dynos are notoriously inaccurate. Some people claim to feel 2 hp gains while others can barely feel a 20 hp gain. What I find impressive is that you can actually feel the gain as low as 3000 rpm.
04-08-2004, 01:39 PM
#23
Race Director
Originally posted by Geo
Me, I'll probably end up buying his $650 header. I'll be making a custom CAI with a good AFM adapter that I'm going to have to design on CAD myself. I wish I could run a cam.
Me, I'll probably end up buying his $650 header. I'll be making a custom CAI with a good AFM adapter that I'm going to have to design on CAD myself. I wish I could run a cam.
No saying Jon's claims are junk, but DO expect to need very special exhaust after the header to get all the gains. Not expensive probably, but paticular. Jon will probably let you know all the details.
04-08-2004, 01:59 PM
#24
Race Director
I don't know how to put this without offending a lot of people......
Look, 16 hp is a pretty damned good gain for a single mod on a small NA engine. Worth it? Yes, that's a personal decision.
But, people lament the lack of effective mods available for a 8v NA. Hey, if you want a turbo, buy a freaking turbo. People marvel at the Honduhs making huge power with NA engines. Why does that happen? It happens because enough people with Honduhs spend the money to pursue more power. I mean, come on, a lot of Porsche people like to laugh at the Honduh crowd, but they spend the money and make the gains. The 944 people just whine about not being able to make gains. Gains are there to be had if you spend the money. And don't tell me the wizzards of Weissach produced an engine that cannot be improved upon. That's silly. People do it. Look, if this offends anyone, I'm sorry, but that's the blunt truth. I'm not out to diss anyone or the 944 or Porsche.
Here's a comparison for you. Back in 99 I bought a spare engine for Sentra SE-R (140 bhp stock). I rebuilt it top to bottom with the best stuff available at the time. I added piston squirters, had the pistons coated by Swain on the skirts and domes. I installed slightly larger pistons from a 300ZX with the domes removed to produce 10:1 compression (from 9.5:1). I had $2,000 in head work done, including welding and cloverleafing the combustion chambers to increase detonation resistance and increase compression to 11:1. I ran the best cams available at the time. Low mass pulleys and flywheel, everything balanced. Adjustable cam gears. Latest header, ordered specially without coating so I could send it to Swain for their White Lightning coating. At the time there was one other engine like it in the country. Total bill, $6,000. Just under 200 bhp. How many 8v drivers here are willing to invest that kind of money in their engine for that kind of gain?
The point is that NA horsepower isn't cheap. It requires no small investment. NA horsepower comes in small increments (although 12-18hp is no small increment). But, to get the gains, you have to spend. Is it not worth it? Perhaps not. Perhaps it is. But to get the gains, you have to spend the money.
Shoot, if Jon can make 185 bhp from an IT legal engine (stock internals, including cams), I think NA power is there to be made.
Look, 16 hp is a pretty damned good gain for a single mod on a small NA engine. Worth it? Yes, that's a personal decision.
But, people lament the lack of effective mods available for a 8v NA. Hey, if you want a turbo, buy a freaking turbo. People marvel at the Honduhs making huge power with NA engines. Why does that happen? It happens because enough people with Honduhs spend the money to pursue more power. I mean, come on, a lot of Porsche people like to laugh at the Honduh crowd, but they spend the money and make the gains. The 944 people just whine about not being able to make gains. Gains are there to be had if you spend the money. And don't tell me the wizzards of Weissach produced an engine that cannot be improved upon. That's silly. People do it. Look, if this offends anyone, I'm sorry, but that's the blunt truth. I'm not out to diss anyone or the 944 or Porsche.
Here's a comparison for you. Back in 99 I bought a spare engine for Sentra SE-R (140 bhp stock). I rebuilt it top to bottom with the best stuff available at the time. I added piston squirters, had the pistons coated by Swain on the skirts and domes. I installed slightly larger pistons from a 300ZX with the domes removed to produce 10:1 compression (from 9.5:1). I had $2,000 in head work done, including welding and cloverleafing the combustion chambers to increase detonation resistance and increase compression to 11:1. I ran the best cams available at the time. Low mass pulleys and flywheel, everything balanced. Adjustable cam gears. Latest header, ordered specially without coating so I could send it to Swain for their White Lightning coating. At the time there was one other engine like it in the country. Total bill, $6,000. Just under 200 bhp. How many 8v drivers here are willing to invest that kind of money in their engine for that kind of gain?
The point is that NA horsepower isn't cheap. It requires no small investment. NA horsepower comes in small increments (although 12-18hp is no small increment). But, to get the gains, you have to spend. Is it not worth it? Perhaps not. Perhaps it is. But to get the gains, you have to spend the money.
Shoot, if Jon can make 185 bhp from an IT legal engine (stock internals, including cams), I think NA power is there to be made.
04-08-2004, 02:03 PM
#25
Race Director
Originally posted by M758
Geo... You will also need a custom exhaust behind the header to see real gains. I had a fellow 944-spec guy contact Jon. He wanted a garuntee that back to back dyno testing would give at least 5hp. Jon informed him that he also needed to finishe the rest of the exhaust in a very specific way to see all the gains. In the end with no garuntee he never got the header.
No saying Jon's claims are junk, but DO expect to need very special exhaust after the header to get all the gains. Not expensive probably, but paticular. Jon will probably let you know all the details.
Geo... You will also need a custom exhaust behind the header to see real gains. I had a fellow 944-spec guy contact Jon. He wanted a garuntee that back to back dyno testing would give at least 5hp. Jon informed him that he also needed to finishe the rest of the exhaust in a very specific way to see all the gains. In the end with no garuntee he never got the header.
No saying Jon's claims are junk, but DO expect to need very special exhaust after the header to get all the gains. Not expensive probably, but paticular. Jon will probably let you know all the details.
Hell, once the car is done I may even spend the money to buy a stock blueprint cam (optimizes factory specs within the tolerances of the factory). That too is supposed to offer small gains.
