9000rpm
Jan 3, 2010, 08:43 PM
#2
Absoltely not, we normally take stock block big turbo cars to around 8k going thru the traps in the 1/4 but never ever going to get 9k out of them. You would need a built motor that has been professionally specd out and built within specs with a pretty strong valvetrain with something like a GSC beehive spring or Supertech duals.
Jan 3, 2010, 08:50 PM
#3
Evolved Member
iTrader: (6)
Join Date: Sep 2005
Location: NYC
Posts: 2,269
Likes: 0
Received 0 Likes
on
0 Posts
a completely stock block and head cannot rev to 9K safely. PERIOD!
As said before, you need preferably a built block and a good valvetrain that can support such revs... both your bottom end and upper end can suffer... and of course it is suggested to stay 2.0....
My choice was powerful yet lightweight bottom end (Wiseco 1400hd, Carrillos with carr bolts, acl everything, fully balanced, removed balance shafts, fluidampr damper for vibrations, and Supertech dual springs, ti retainers, cossie cams and o-ringed head)...
Voilas!!!
and here's some videos revving to 9000rpm
http://www.youtube.com/watch?v=Cj2wpydo0kU
http://www.youtube.com/watch?v=TYZLJ2YP-MI
As said before, you need preferably a built block and a good valvetrain that can support such revs... both your bottom end and upper end can suffer... and of course it is suggested to stay 2.0....
My choice was powerful yet lightweight bottom end (Wiseco 1400hd, Carrillos with carr bolts, acl everything, fully balanced, removed balance shafts, fluidampr damper for vibrations, and Supertech dual springs, ti retainers, cossie cams and o-ringed head)...
Voilas!!!
and here's some videos revving to 9000rpm
http://www.youtube.com/watch?v=Cj2wpydo0kU
http://www.youtube.com/watch?v=TYZLJ2YP-MI
Last edited by kouzman; Jan 3, 2010 at 08:52 PM.
Jan 3, 2010, 09:03 PM
#5
Evolved Member
iTrader: (6)
Join Date: Sep 2005
Location: NYC
Posts: 2,269
Likes: 0
Received 0 Likes
on
0 Posts
Actually if you are referring to my videos, they were track pulls, actually some of my first ones on the new setup....
I know i can even rev higher, but then we have to worry about other parts, like the oil pump, water pump etc... I feel that 9000rpm is a fairly safe limit.... I will raise it, only when i have to use more revs to finish the 1/4 mile in 4th...
Who knows, i might even do an electric water pump and a modified oil pump... We ll see!
Jan 3, 2010, 09:19 PM
#7
damn nice videos! always thought the stock 7k seemed low considering longer duration IX cams versus the 1G cams which had the same 7k limit. I realize not much additional power is available past 6500 but I have had mine to 7500 plenty of times with no issues. FP says their 4R cams can be used to 8000 and 9000 with springs and the stock springs are really stout and I have read posts of plenty of people running larger cams to 9k without springs reliable who knows but it has happened.
Trending Topics
Jan 3, 2010, 09:43 PM
#10
ted first your wisdom I'm not questioning now but how would you respond to this thread https://www.evolutionm.net/forums/7347896-post17.html
Jan 3, 2010, 09:58 PM
#11
ted first your wisdom I'm not questioning now but how would you respond to this thread https://www.evolutionm.net/forums/7347896-post17.html
- The spring specs I posted above speak for themselves. If you know anything about spring rates, you know what it means.
- The belief that the better cam sets we use have soft ramp rates as compared to NA engines isn't quite the case. Some cam sets do (e.g. HKS) but not the ones that make the most power.
- Inadequate spring pressure compromises power due to inaccurate lobe tracking. This creates valvetrain deflection issues, and that is no good. It's always better to have a little more than you really need than a little less.
- The Brian Crower cams mentioned in the post are demonstrably down on power as compared to the top cam sets (see AMS' testing), very likely because they do have relatively lazy ramp rates that would be more forgiving to stock springs (like HKS cams).
Using stock springs with a top tier cam set is like putting cheap tires on a new Z06 Corvette. You can do it, but the tires aren't suited to the performance of the car.
Jan 27, 2010, 04:13 PM
#13
Newbie
iTrader: (1)
Join Date: Sep 2009
Location: NB, CANADA
Posts: 37
Likes: 0
Received 0 Likes
on
0 Posts
Took this from a post on dsmtalk from
OK courtesy of Josh (our machine shop manager) Took some time out of his day to put the squeeze to some of these for comparisons sake. PLEASE KEEP IN MIND THESE NUMBERS ARE USED TO SIMPLY REPRESENT A SPRING COMPARISON. THIS IS NOT TAKING INTO ACCOUNT VALVE GUIDE/SEAL TO RETAINER CLEARANCE ETC. In other words... this is simply a straight on spring test. If you try to use these numbers to set up your head. I / we are not responsible for you not being able to ****ing read.
So lets get on with it then.
Some general data used in the test to "standardize" the results a bit.
Installed height general numbers (1.560) for comparison; this includes the mitsu locator given at an average value of 40.
.410 will be used for cam lift.
As follows;
DSM
Coil Bind
1.115
60
1.175 SAFE
1.560 = 68lbs
.030
1.530 = 72lbs
.410 LIFT
1.120 = 192lbs
But we're under where we need to be. When performing this last squeeze there was no daylight left. ABORT ABORT! DSM spring is KO'd. Even if we pull the shim its still over.
EVO
Coil Bind
1.035
60
1.095 SAFE
Installed height general numbers (1.560) for comparison; this includes the mitsu locator given at an average value of 40.
1.560 = 65lbs
.030 shim
1.530 = 72lbs
.410 will be used to simulate cam lift
1.120 = 154lbs
In referance to our original coil bind number, we can see we still have room on the Evo spring. Showing the benefits of the semi-beehive springs and its much looser coils. It would take a 60 thou shim to max this scenario out.
MANLEY
Coil Bind
.925
60
.985 SAFE
1.560 = 78lbs
.030 shim
1.530 = 88lbs
.410
1.120 = 204lbs
As we can see here there obviously isn't going to be any problems in sight.
This is why you pay $2XX for springs and retainers.
NOW... lets see what these things weigh.
DSM
Spring: 56.3g
Retainer: 13.7g
Evo
Spring: 39g
Retainer: 3.9g !!! HOLY ****!
Manley
Spring: 42.7g
Retainer: 8.9g
This will give you an idea of why even though the Evo spring has the least pressure of all the springs, it is still alot more versatile than the DSM spring. With its extended coil gap, and feather weight retainer, it alows for a greater range in coil bind and following capabilities.
So after seeing that, and running say 272 hks cams, what do you guys think about using the stock evo 8 springs with say a 30-40 thou shim to bring up the spring rate. Would this even be an option to bring up the rev limit? For discussion sake the bottom end can handle whatever revs we throw at it. Lets here what you guys think...
Originally Posted by Asmodeus
OK courtesy of Josh (our machine shop manager) Took some time out of his day to put the squeeze to some of these for comparisons sake. PLEASE KEEP IN MIND THESE NUMBERS ARE USED TO SIMPLY REPRESENT A SPRING COMPARISON. THIS IS NOT TAKING INTO ACCOUNT VALVE GUIDE/SEAL TO RETAINER CLEARANCE ETC. In other words... this is simply a straight on spring test. If you try to use these numbers to set up your head. I / we are not responsible for you not being able to ****ing read.
So lets get on with it then.
Some general data used in the test to "standardize" the results a bit.
Installed height general numbers (1.560) for comparison; this includes the mitsu locator given at an average value of 40.
.410 will be used for cam lift.
As follows;
DSM
Coil Bind
1.115
60
1.175 SAFE
1.560 = 68lbs
.030
1.530 = 72lbs
.410 LIFT
1.120 = 192lbs
But we're under where we need to be. When performing this last squeeze there was no daylight left. ABORT ABORT! DSM spring is KO'd. Even if we pull the shim its still over.
EVO
Coil Bind
1.035
60
1.095 SAFE
Installed height general numbers (1.560) for comparison; this includes the mitsu locator given at an average value of 40.
1.560 = 65lbs
.030 shim
1.530 = 72lbs
.410 will be used to simulate cam lift
1.120 = 154lbs
In referance to our original coil bind number, we can see we still have room on the Evo spring. Showing the benefits of the semi-beehive springs and its much looser coils. It would take a 60 thou shim to max this scenario out.
MANLEY
Coil Bind
.925
60
.985 SAFE
1.560 = 78lbs
.030 shim
1.530 = 88lbs
.410
1.120 = 204lbs
As we can see here there obviously isn't going to be any problems in sight.
This is why you pay $2XX for springs and retainers.
NOW... lets see what these things weigh.
DSM
Spring: 56.3g
Retainer: 13.7g
Evo
Spring: 39g
Retainer: 3.9g !!! HOLY ****!
Manley
Spring: 42.7g
Retainer: 8.9g
This will give you an idea of why even though the Evo spring has the least pressure of all the springs, it is still alot more versatile than the DSM spring. With its extended coil gap, and feather weight retainer, it alows for a greater range in coil bind and following capabilities.
Jan 27, 2010, 07:45 PM
#14
Evolved Member
iTrader: (6)
Join Date: Sep 2008
Location: Denver
Posts: 766
Likes: 0
Received 0 Likes
on
0 Posts
Stock motor, Head, ARP head studs, 55k miles, I have been to 9k RPM's 30+ times. My rev limiter is set at 9k. The only time I get close is at the strip in 4th gear. I shift at 7800-8000 with the Red and run it out to 8700+ RPM's in 4th on the MR 6 speed.
Mar 7, 2011, 06:34 PM
#15
Well a long time has passed since I first asked this question. Threw a rod not related to rpm though. Getting a map stage2 10.5 CR ultimate duty rods beehive springs ported everything to go with previous fp4r cams. E85 build I should be able to safely rev 9k.