Dissappointing AFR 205 Results
01-07-2011, 09:01 PM
#205
Guys,
I was almost tempted to have all of you wait till next week for the numbers but I thought I might get banned or lynched first
Bottom line I wanted to get a tune in the car as quickly as I could obviously but Nick was a little short on time and our schedules kind of conflicted this week. Long story short is we didn't have a whole lot of time to spend on it and Nick did a great job in the time that we did spend (less than a couple of hours) but he purposely left the tune really conservative with fueling in the mid/high 12's across the board and only 22-24 degrees of timing at WOT! (Tony almost fainted when he heard that!)
I'm going back next week to see what we left under the table but Nick (and Tony) are confident its got a good bit more in it. Not sure if I'm going back there Wednesday or Saturday but when I do I will revise the thread with the new numbers.
Even now though the car feels unreal, power and torque everywhere. It really pulls hard upstairs.
I was almost tempted to have all of you wait till next week for the numbers but I thought I might get banned or lynched first
Bottom line I wanted to get a tune in the car as quickly as I could obviously but Nick was a little short on time and our schedules kind of conflicted this week. Long story short is we didn't have a whole lot of time to spend on it and Nick did a great job in the time that we did spend (less than a couple of hours) but he purposely left the tune really conservative with fueling in the mid/high 12's across the board and only 22-24 degrees of timing at WOT! (Tony almost fainted when he heard that!)
I'm going back next week to see what we left under the table but Nick (and Tony) are confident its got a good bit more in it. Not sure if I'm going back there Wednesday or Saturday but when I do I will revise the thread with the new numbers.
Even now though the car feels unreal, power and torque everywhere. It really pulls hard upstairs.
01-07-2011, 09:02 PM
#206
01-07-2011, 09:31 PM
#208
01-08-2011, 01:34 AM
#210
Finally the day of reckoning is upon us....LOL
Well....its been a long road but as they say good things are worth waiting for (and thankfully we saw good things!).
I was very pleased with the results, especially considering how soft the tune-up is right now. I hate making predictions (because they occasionally lead to disappointment), but my guess is there is 490 to 495 in this combination with no other changes other than spending a little more time with the tune.
The best part about the results (IMO) is the shape of the curve more so than the gains in peak power which were certainly welcome. This was an interesting test because there was so little actually changed here. Displacement exactly the same and the compression a hair lower due to the valve reliefs cut into the pistons to accept the larger bumpstick. The only variables were the ported heads and the larger cam and the sharper guys here know that larger cam installs are ALWAYS a compromise....you trade low and midrange torque and horsepower for an improvement in the top end of the curve (peak HP increases) and it usually shows to be a narrow range of gains compared to the larger range of trade offs (losses down low and in the middle). Big cams sound great and are effective tools if your focusing on high RPM power improvements but they can significantly hurt the area under the curve and the drivability of the entire package. They must be selected and managed properly.
Perfect example of that "typical" scenario seen in this gragh Ron @ Vengeance posted about a month ago (when his customer actually decided to go with a milder set-up which really enhanced the area under the curve). Look at how the larger cam set-up annihalates the lower part of the curve....
Note that the new curve Rudy's engine produced was alot fatter everywhere and even with a 12' larger intake lobe still managed to surpass the smaller cams power and torque as early as 3200 RPM....and my guess is that crossover point happens even earlier than that when we add some timing to the engine next week.
For me that's rewarding because that's the more efficient heads showing you their stuff....the engine became a more efficient air pump and produced higher volumetric efficiency numbers with the airflow curve and improved velocity provided by the new heads. That fact is also evident by noting the improvement in peak torque output as well. Big cams usually have just the opposite effect....hurting peak torque output but allowing the torque curve to hang on longer at higher RPM's which then brings in the additional power via mathmatics (Torque X RPM = Horsepower).
I point all this out so the guys following this thread can learn something and have a better appreciation of the results (OK....its slightly self serving as well
), but seriously....I really do try to bring as much "Tech" to this board as I can and these results are very interesting when you really analyze what happened here.
Truth be told I mentioned to Rudy over a month ago that my hopes were the better flowing more efficinet heads would counter the losses in the bottom and middle of the curve that I knew the larger cam and additional overlap would create, and that once we crossed 4500 or so the larger cam and the additional airflow would start to show its stuff with the power curves diverging and looking better and better the more RPM we turned. What I was hoping for was minimal to no losses down low and in the middle and a much stronger charge upstairs....all the benefits of a larger cam without any of the trade-offs normally associated with it. Fact is the results I saw here were slightly better than I expected but I think some of that stems from the fact the first cam was all wrong for the AFR heads. A smaller exhaust lobe while likely hurting the peak power of the former package a bit, would have notably fattened the bottom and the middle of the previous curve.
You guys still with me here....LOL
What will get real interestng is what we see next week though....I have hopes we can pick the entire curve up even more and see peak torque possibly exceed 420
Should be pretty interesting and in fact I may even try to attend the testing depending on when it actually goes down.
Good stuff guys....
Looks like 2011 is off to a good start!
Cheers,
Tony
PS....Now can we lobby to change the title of this thread!
Well....its been a long road but as they say good things are worth waiting for (and thankfully we saw good things!).
I was very pleased with the results, especially considering how soft the tune-up is right now. I hate making predictions (because they occasionally lead to disappointment), but my guess is there is 490 to 495 in this combination with no other changes other than spending a little more time with the tune.
The best part about the results (IMO) is the shape of the curve more so than the gains in peak power which were certainly welcome. This was an interesting test because there was so little actually changed here. Displacement exactly the same and the compression a hair lower due to the valve reliefs cut into the pistons to accept the larger bumpstick. The only variables were the ported heads and the larger cam and the sharper guys here know that larger cam installs are ALWAYS a compromise....you trade low and midrange torque and horsepower for an improvement in the top end of the curve (peak HP increases) and it usually shows to be a narrow range of gains compared to the larger range of trade offs (losses down low and in the middle). Big cams sound great and are effective tools if your focusing on high RPM power improvements but they can significantly hurt the area under the curve and the drivability of the entire package. They must be selected and managed properly.
Perfect example of that "typical" scenario seen in this gragh Ron @ Vengeance posted about a month ago (when his customer actually decided to go with a milder set-up which really enhanced the area under the curve). Look at how the larger cam set-up annihalates the lower part of the curve....
Note that the new curve Rudy's engine produced was alot fatter everywhere and even with a 12' larger intake lobe still managed to surpass the smaller cams power and torque as early as 3200 RPM....and my guess is that crossover point happens even earlier than that when we add some timing to the engine next week.
For me that's rewarding because that's the more efficient heads showing you their stuff....the engine became a more efficient air pump and produced higher volumetric efficiency numbers with the airflow curve and improved velocity provided by the new heads. That fact is also evident by noting the improvement in peak torque output as well. Big cams usually have just the opposite effect....hurting peak torque output but allowing the torque curve to hang on longer at higher RPM's which then brings in the additional power via mathmatics (Torque X RPM = Horsepower).
I point all this out so the guys following this thread can learn something and have a better appreciation of the results (OK....its slightly self serving as well
), but seriously....I really do try to bring as much "Tech" to this board as I can and these results are very interesting when you really analyze what happened here.Truth be told I mentioned to Rudy over a month ago that my hopes were the better flowing more efficinet heads would counter the losses in the bottom and middle of the curve that I knew the larger cam and additional overlap would create, and that once we crossed 4500 or so the larger cam and the additional airflow would start to show its stuff with the power curves diverging and looking better and better the more RPM we turned. What I was hoping for was minimal to no losses down low and in the middle and a much stronger charge upstairs....all the benefits of a larger cam without any of the trade-offs normally associated with it. Fact is the results I saw here were slightly better than I expected but I think some of that stems from the fact the first cam was all wrong for the AFR heads. A smaller exhaust lobe while likely hurting the peak power of the former package a bit, would have notably fattened the bottom and the middle of the previous curve.
You guys still with me here....LOL
What will get real interestng is what we see next week though....I have hopes we can pick the entire curve up even more and see peak torque possibly exceed 420
Should be pretty interesting and in fact I may even try to attend the testing depending on when it actually goes down.
Good stuff guys....
Looks like 2011 is off to a good start!
Cheers,
Tony
PS....Now can we lobby to change the title of this thread!
Last edited by Tony Mamo @ AFR; 01-08-2011 at 02:08 AM.
01-08-2011, 08:07 AM
#211
Very impressive numbers especially considering the low timing used. I've seen several 205 combos on here (mine included) that make best power up to around 28 deg timing.
Tony/Bludevil - couple questions.
1. You posted the old vs new flow numbers earlier in the thread - were those new numbers from the same hole as the old numbers? I know the new ones will be consistent across the board but you said the old numbers may not.
2. You also said the chamber was 59.5cc earlier (I thought they started at 62)...what compression is the motor at now knowing that it's got small valve reliefs on the intake side. I run a 231 duration LSL lobe on my intake side and with 62cc chambers and .040" gaskets I just barely cut the intake side - I only took out .025" which gave me almost 0.100" PTV. Just curious on the compression - I imagine you had to flycut more with the 235 duration plus more milling.
3. Being that the last cam was pretty small on the intake side compared to the new one - how much of the power gain would you attribute to the cam versus the ported heads?
Tony/Bludevil - couple questions.
1. You posted the old vs new flow numbers earlier in the thread - were those new numbers from the same hole as the old numbers? I know the new ones will be consistent across the board but you said the old numbers may not.
2. You also said the chamber was 59.5cc earlier (I thought they started at 62)...what compression is the motor at now knowing that it's got small valve reliefs on the intake side. I run a 231 duration LSL lobe on my intake side and with 62cc chambers and .040" gaskets I just barely cut the intake side - I only took out .025" which gave me almost 0.100" PTV. Just curious on the compression - I imagine you had to flycut more with the 235 duration plus more milling.
3. Being that the last cam was pretty small on the intake side compared to the new one - how much of the power gain would you attribute to the cam versus the ported heads?
Last edited by Red99TA; 01-08-2011 at 08:25 AM.
01-08-2011, 02:22 PM
#213
Very impressive numbers especially considering the low timing used. I've seen several 205 combos on here (mine included) that make best power up to around 28 deg timing.
Tony/Bludevil - couple questions.
1. You posted the old vs new flow numbers earlier in the thread - were those new numbers from the same hole as the old numbers? I know the new ones will be consistent across the board but you said the old numbers may not.
2. You also said the chamber was 59.5cc earlier (I thought they started at 62)...what compression is the motor at now knowing that it's got small valve reliefs on the intake side. I run a 231 duration LSL lobe on my intake side and with 62cc chambers and .040" gaskets I just barely cut the intake side - I only took out .025" which gave me almost 0.100" PTV. Just curious on the compression - I imagine you had to flycut more with the 235 duration plus more milling.
3. Being that the last cam was pretty small on the intake side compared to the new one - how much of the power gain would you attribute to the cam versus the ported heads?
Tony/Bludevil - couple questions.
1. You posted the old vs new flow numbers earlier in the thread - were those new numbers from the same hole as the old numbers? I know the new ones will be consistent across the board but you said the old numbers may not.
2. You also said the chamber was 59.5cc earlier (I thought they started at 62)...what compression is the motor at now knowing that it's got small valve reliefs on the intake side. I run a 231 duration LSL lobe on my intake side and with 62cc chambers and .040" gaskets I just barely cut the intake side - I only took out .025" which gave me almost 0.100" PTV. Just curious on the compression - I imagine you had to flycut more with the 235 duration plus more milling.
3. Being that the last cam was pretty small on the intake side compared to the new one - how much of the power gain would you attribute to the cam versus the ported heads?
Question 1: Not sure whether I flowed the same hole or not. Truthfully its unlikely but the valve work done to the head previously and the work when I was finished was both very consistent (meaning that the previous valvejob and valve heights were all very similar and when I was finished of course they were also very similar). In short, there is a very high likelihood the flow numbers I shared with you both before and after would have been very representative. I didn't see anything during the course of the disassembly that would have shown me anything different (and its not like the former dyno numbers were shabby considering the size of the cam used....hell it was probably above average considering this was not a fully optimized set-up with the two obvious ingredients missing being the ported FAST and an EWP).
Question 2: I'm not sure nor do I remember whether the heads were "suppose" to be 62 cc's or not (maybe Rudy can comment) but they were certainly 60 cc's before I performed any of my work (I poured both heads to confirm) which is pretty stout for a no valve relief 91 octane set-up. Truthfully I was a little disappointed I couldn't add a tad more compression to the mix, but knowing we would pick up a little volume in the pistons with the fly-cutting I decided to finish them a hair smaller at 59.5 cc's (leaving the net static CR a little less than the original combo). I was concerned with the heads working so well now they were going to fill the cylinder better and create a higher chance of detonating on 91 octane. I wanted to to be a hair more conservative but I also know the large cam would help bleed off some cylinder pressure at low speeds as well so that made me a little more comfy with my decision to cut them to 59.5 (they were almost 63 cc's after my porting work with the new valves btw).
Regarding the depths of the notches I told Rudy .080 should give him a good margin of safety on P to V and I believe thats what he instructed his shop to remove which would be worth probably 1 - 1.5 cc's of volume loss....more than the .5 cc's I milled the chambers lower when it was all said and done.
Question 3: Once you already have a performance cam in the engine going bigger is very much the law of diminishing returns. You dont see huge gains going from a low/mid 220's cam to a mid 230's grind (a fraction of what you see going from stock to the 220's performance grind). See the Vengeance graph I posted above....they only saw a 12 HP gain in the peak power output with a cam almost exactly the same amount larger (around 12' or so). Also the key is the gains we witnessed on the bottom.....read my last response more closely if you may have just glazed over it....I discussed that all of the torque gains were attributed to the heads and why.
The million dollar question....whats my best guess on what was worth what?? I'm going to say the head work was worth ALL of the gains in peak torque witnessed which may be around 15-20 ft/lbs when the smoke clears next week and I would say the HP gains could be split right done the middle give or take. If we see 40 more ponies net after the re-tune I would say half is attributed to the heads....half attributed to the additional duration and much more "ideal" cam selection for this head and this combination. Note when selecting this cam I could have easily stepped it up a bit more but I wanted to give Rudy something that would still be a good all around piece on the street and not be a total pooch on the bottom.
Ported 102 and an EWP on this bad-boy down the road and this is a legit low 500 RWHP ride fellas without a monster cam and small really efficient heads which makes the low and midrange torque still very explosive.....win-win....you just have to decide if you can justify spending all the time, money, and effort to get here!
Regards,
Tony
Last edited by Tony Mamo @ AFR; 01-08-2011 at 02:51 PM.
01-08-2011, 05:13 PM
#216
Years ago, I thought Tony was BSing when he said he was close to getting 500 RWHP with AFR 205 heads and his 228 cam.
Well I have the 228 cam, AFR milled to 62 and im at 450 RWHP with 3.90s. With a FAST 102 set up and EWP, Id be right at 500 RWHP with a baby cam.
Keep up the good work Tony
Well I have the 228 cam, AFR milled to 62 and im at 450 RWHP with 3.90s. With a FAST 102 set up and EWP, Id be right at 500 RWHP with a baby cam.
Keep up the good work Tony
01-08-2011, 06:22 PM
#217
Years ago, I thought Tony was BSing when he said he was close to getting 500 RWHP with AFR 205 heads and his 228 cam.
Well I have the 228 cam, AFR milled to 62 and im at 450 RWHP with 3.90s. With a FAST 102 set up and EWP, Id be right at 500 RWHP with a baby cam.
Keep up the good work Tony
Well I have the 228 cam, AFR milled to 62 and im at 450 RWHP with 3.90s. With a FAST 102 set up and EWP, Id be right at 500 RWHP with a baby cam.
Keep up the good work Tony
Good job guys and way to stick with it Rudy
01-08-2011, 08:45 PM
#219
Thanks alot. Yeah i just put some new tires on the car. They have about 500 miles on them so im all good in the tire department. I also have a set of hoosier D/R's..
01-08-2011, 08:48 PM
#220