Any tips on cam, springs & other valvetrain, crank pin kit for Radix?
09-28-2010, 03:16 PM
#171
Your dyno guy makes no sense....why did he only graph to 5k? Why not pull to 6k+ to see where you make power? If its too much speed do it in 2nd gear. The torque differences between 2nd and 3rd isnt that much (less than 10% in my case), and it will give you data over the whole range.
The different numbers he is throwing around sound like with and without weather corrections.
Min and avg horsepower numbers are pretty useless....obviously, the min is going to be at the lowest RPM. The min, max, and avg torque numbers on the other hand are very useful if you specificy an rpm range since that will give you a good idea of your torque curve.
Take a picture of the dyno sheet with a camera or a phone or something, you dont need to scan it.
The different numbers he is throwing around sound like with and without weather corrections.
Min and avg horsepower numbers are pretty useless....obviously, the min is going to be at the lowest RPM. The min, max, and avg torque numbers on the other hand are very useful if you specificy an rpm range since that will give you a good idea of your torque curve.
Take a picture of the dyno sheet with a camera or a phone or something, you dont need to scan it.
I wondered bout that (2nd gear pull).
That doesn't create stress to 2nd gear? Also, don't u have to worry bout driveshaft critical speed being reached even sooner?
And that was only today after I saw NicD's results. His pale mine. I have cats tho & 3.42s not 3.23s. He doesn't do WCF anymore, said he did that one day & w/in the span of an hours or a few hrs., there were 5-7 variances. So he says, it is what it is.
Sheet went from 3-5,000 RPM. I just filled my digital stick up the other day, so camera option is out.
Plus, I didn't think a camera would blow it up enuff so it was readable?Oh ya, at my last track outing I think I went thru 1/4 traps at 4400, maybe 4800. I didn't take good enuff noted like I usu. do due to time constraints. Soon as I reached the end, I let off gas, & it instantly went from that 4xxx RPMs to ~3300. That's prolly a sign of more gear needed. The 4k+ isn't maximizing my power, but when it drops to 3k+, is that just the stall of the converter, or is it only a sign of more gear needed?
Last edited by fastnblu; 09-28-2010 at 04:18 PM.
09-28-2010, 03:53 PM
#172
If he dyno'd it up to that rpm then yes he can print you out a good sheet, but if he stopped pulling at 5k then thats all you get. Erase 1 picture and go snap one of the sheet, heck a camera phone would work too. As long as its 3+mp it will be plenty.
Driveshaft speed is directly related to vehicle speed, not engine rpm. Think about it, rev up in neutral, whats your driveshaft speed? Top of 2nd gear is around 75, and top of third is around 135 depending on gearing, which is why a lot of guys that break driveshafts do it on the dyno in 3rd gear.
3rd gear is usually the strongest in the transmission (or 1st), but you arent making enough power to worry about the strength differences between 2nd and 3rd.
The big RPM drop when you let off the gas is a couple things. Mainly the truck is probably shifting in 4th gear, the converter is no longer slipping, and the engine is slowing down. You want to spend as much time in the peak of the powerband as possible which is why seeing the dyno chart would really be useful and a lot of guys shift at 6k+
Driveshaft speed is directly related to vehicle speed, not engine rpm. Think about it, rev up in neutral, whats your driveshaft speed? Top of 2nd gear is around 75, and top of third is around 135 depending on gearing, which is why a lot of guys that break driveshafts do it on the dyno in 3rd gear.
3rd gear is usually the strongest in the transmission (or 1st), but you arent making enough power to worry about the strength differences between 2nd and 3rd.
The big RPM drop when you let off the gas is a couple things. Mainly the truck is probably shifting in 4th gear, the converter is no longer slipping, and the engine is slowing down. You want to spend as much time in the peak of the powerband as possible which is why seeing the dyno chart would really be useful and a lot of guys shift at 6k+
09-28-2010, 04:14 PM
#173
IDK what is goin on w/. this site. It's goin slow & it didn't put up what I added to my last post. But basically I said this, I'm not lookin for the fastest, most radical cam or truck nor a dyno queen. Nor track star. I prefer track results over a dyno, don't wanna kill mileage on my DD. This is the cam I had & have. Who knows if I had to do again, & never bought it yrs. ago. I tend to think a GT2-3 would be in there. But there are some others I might would try. That doesn't mean I don't like this cam tho.
I would suggest one of either 3 things.
- go back and tell him to run it up more to at least 6200 imo, can do it in 2nd if that makes you feel more comfortable and the drive shaft should be fine..
- find a dynojet with a different tuner and get a 2nd opinion so to speak
- go to the track and get the best pass you think possible and you can get some decent numbers/comparison on that, but you wont get to see the curves/powerbands like you would a dyno sheet..
also dont worry about gears yet, i would get your setup all done the way you like it (get the charger on) then you can determine what gears you want. you could probably get close to what you wanted with some calculations, but it wont be perfect.
Skeet is a great example of this imo, he changes gears alot for his n/a and n20 setups to keep him in the right rpm range for power. Gotta go one step at a time grasshopper..
Last edited by skolman91; 09-28-2010 at 04:24 PM.
09-28-2010, 04:35 PM
#174
If he dyno'd it up to that rpm then yes he can print you out a good sheet, but if he stopped pulling at 5k then thats all you get. Erase 1 picture and go snap one of the sheet, heck a camera phone would work too. As long as its 3+mp it will be plenty.
Driveshaft speed is directly related to vehicle speed, not engine rpm. Think about it, rev up in neutral, whats your driveshaft speed? Top of 2nd gear is around 75, and top of third is around 135 depending on gearing, which is why a lot of guys that break driveshafts do it on the dyno in 3rd gear.
3rd gear is usually the strongest in the transmission (or 1st), but you arent making enough power to worry about the strength differences between 2nd and 3rd.
The big RPM drop when you let off the gas is a couple things. Mainly the truck is probably shifting in 4th gear, the converter is no longer slipping, and the engine is slowing down. You want to spend as much time in the peak of the powerband as possible which is why seeing the dyno chart would really be useful and a lot of guys shift at 6k+
Driveshaft speed is directly related to vehicle speed, not engine rpm. Think about it, rev up in neutral, whats your driveshaft speed? Top of 2nd gear is around 75, and top of third is around 135 depending on gearing, which is why a lot of guys that break driveshafts do it on the dyno in 3rd gear.
3rd gear is usually the strongest in the transmission (or 1st), but you arent making enough power to worry about the strength differences between 2nd and 3rd.
The big RPM drop when you let off the gas is a couple things. Mainly the truck is probably shifting in 4th gear, the converter is no longer slipping, and the engine is slowing down. You want to spend as much time in the peak of the powerband as possible which is why seeing the dyno chart would really be useful and a lot of guys shift at 6k+
You say 3rd is the strongest. Is that why Vince prefers will do spirited driving in 3rd? Or cause it's 1:1? Or is OD just weak?
I really wish I took notes on those 5 passes (the outing where I took crappy, incomplete notes). I'm 99% positive I had it in 3rd, cause it falls under spirited driving.
6k+ plus - Is there a RPM threshold that u don't wanna push springs to? Cause I was more under impression, it was the cam that dictates how hard springs get pushed. Or does that apply more to retainers? I didn't see myself needing Ti, so I kept the stock retainers. I heard too many Ti horror stories on here, & didn't see the need for an extra 2-300 rpms. I also didn't think I'd spin this cam past 5500, maybe 5800 or 6000. So tomorrow, when I go to track, u think 6200 is my upper limit on this cam & my 918s?
09-28-2010, 04:49 PM
#175
I understand this, not saying the cam is crap it can and will make good power. But there is a line you gotta draw when what you have just isnt performing up to its potential. Its also kinda hard to tell whats going on with all these variables your throwing out there and for future reference like i know your wanting. IMO you should be making almost 300hp with your mods or 270ish on a mustang.
I would suggest one of either 3 things.
- go back and tell him to run it up more to at least 6200 imo, can do it in 2nd if that makes you feel more comfortable and the drive shaft should be fine..
- find a dynojet with a different tuner and get a 2nd opinion so to speak
- go to the track and get the best pass you think possible and you can get some decent numbers/comparison on that, but you wont get to see the curves/powerbands like you would a dyno sheet..
also dont worry about gears yet, i would get your setup all done the way you like it (get the charger on) then you can determine what gears you want. you could probably get close to what you wanted with some calculations, but it wont be perfect.
Skeet is a great example of this imo, he changes gears alot for his n/a and n20 setups to keep him in the right rpm range for power. Gotta go one step at a time grasshopper..
I would suggest one of either 3 things.
- go back and tell him to run it up more to at least 6200 imo, can do it in 2nd if that makes you feel more comfortable and the drive shaft should be fine..
- find a dynojet with a different tuner and get a 2nd opinion so to speak
- go to the track and get the best pass you think possible and you can get some decent numbers/comparison on that, but you wont get to see the curves/powerbands like you would a dyno sheet..
also dont worry about gears yet, i would get your setup all done the way you like it (get the charger on) then you can determine what gears you want. you could probably get close to what you wanted with some calculations, but it wont be perfect.
Skeet is a great example of this imo, he changes gears alot for his n/a and n20 setups to keep him in the right rpm range for power. Gotta go one step at a time grasshopper..
Anyway, so you're tellin me there's a 25-30hp betwen a Mustang & others? I'll guess you're mainly talkin bout a Dynojet, since they're pretty common.
Gimme a 1/4 prediction, since u seem familiar w/. this cam. I was gonna let the truck shift itself (in 3rd as I did before). After 3 passes, then I'll change. Say, 5500 in all gears? Then try 6200 in all gears to see or take a different approach? I wanna see if your reply mirrors what I'm thinkin.
09-28-2010, 05:00 PM
#177
LQ4 with a gt2-3 cam shifts at 6500 and 6400 for best results, that cam in a 5.3 should be damn close to the same performance wise if not want to shift a 100rpm or so higher. From my testing with the 60e it seems a littl ehigher shift point helps more on the shift recovery even though power is flatlining. The damn gear ratios in the 60e suck. When I swap to an 80e again Im sure the extending shift points probably wont be needed nearly as much. Youre definitely shifting too low if its anywhere below 6K.
09-28-2010, 05:09 PM
#179
LQ4 with a gt2-3 cam shifts at 6500 and 6400 for best results, that cam in a 5.3 should be damn close to the same performance wise if not want to shift a 100rpm or so higher. From my testing with the 60e it seems a little higher shift point helps more on the shift recovery even though power is flatlining. The damn gear ratios in the 60e suck. When I swap to an 80e again Im sure the extending shift points probably wont be needed nearly as much. Youre definitely shifting too low if its anywhere below 6K.
If shift points are set at say, for ex. 5500, whatever, let's use 5500 tho. If computer shifts, it'll do so at that RPM. Is it possible to manually override beyond 5500, or will it still only shift @ 5500, but w/. me rowing thru the gears? Just curious.
09-28-2010, 05:21 PM
#180
Anyway, so you're tellin me there's a 25-30hp betwen a Mustang & others? I'll guess you're mainly talkin bout a Dynojet, since they're pretty common.
Gimme a 1/4 prediction, since u seem familiar w/. this cam. I was gonna let the truck shift itself (in 3rd as I did before). After 3 passes, then I'll change. Say, 5500 in all gears? Then try 6200 in all gears to see or take a different approach? I wanna see if your reply mirrors what I'm thinkin.
Gimme a 1/4 prediction, since u seem familiar w/. this cam. I was gonna let the truck shift itself (in 3rd as I did before). After 3 passes, then I'll change. Say, 5500 in all gears? Then try 6200 in all gears to see or take a different approach? I wanna see if your reply mirrors what I'm thinkin.
If your going to go their and be conservative like i know you prob will
, id at least do 5800..If it were me id prob do something like what gmctrk mentioned, maybe 100rpm less.
Really its up to you to mess with it, go out there and see what runs the best..
My guess for a time when compared to before times would prob be a consistent 14.4 range, but imo should be in the 14.0 range.. Hopefully im wrong and you will be in the latter range, good luck..
