In your opinion, does this look like a valvespring problem?
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From: Rockland County, NY
In your opinion, does this look like a valvespring problem? This gives you an idea of my problem
<img src="http://www.fbody.com/members/phil99ta/phildyno2.jpg" alt="" />
I've seen other graphs of the TR224 cam (and most other 220+ duration cams for that matter) and its supposed to pull all the way to 6500 before it starts dropping off. Notice how mine nose dives at 6200.
Do you think weak valvesprings are the most probable cause?
The graph posted is from last year and just this past weekend I dynoed 5hp less with the addition of !cats and LS1 Edit tuning <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> (although i picked up 10hp/10ft lbs from first to last pull with the tuning)I was pretty shocked to say the least. My only guess is that the valvesprings have gotten weaker since the last time I dynoed.
I'm most likely going to put in K750s since my only other option is to have the heads removed and sent to ARE for double springs. I just hope that these springs are strong enough. I'd really hope to break the 400rhwp barrier with the car pulling up top better.
<img src="http://www.fbody.com/members/phil99ta/phildyno2.jpg" alt="" />
I've seen other graphs of the TR224 cam (and most other 220+ duration cams for that matter) and its supposed to pull all the way to 6500 before it starts dropping off. Notice how mine nose dives at 6200.
Do you think weak valvesprings are the most probable cause?
The graph posted is from last year and just this past weekend I dynoed 5hp less with the addition of !cats and LS1 Edit tuning <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> (although i picked up 10hp/10ft lbs from first to last pull with the tuning)I was pretty shocked to say the least. My only guess is that the valvesprings have gotten weaker since the last time I dynoed.
I'm most likely going to put in K750s since my only other option is to have the heads removed and sent to ARE for double springs. I just hope that these springs are strong enough. I'd really hope to break the 400rhwp barrier with the car pulling up top better.
I can shift faster than you.
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Re: In your opinion, does this look like a valvespring problem? Phil, there is defintely something wrong in the upper RPMs. What lifters and pushrods are you using? Was this occuring on every single pull? Were the 941s brand new when they were installed on your car? How many miles on the setup?
Here is my dyno graph with the TR224 cam/stock heads and Comp 918s:
Thunder 224 cam
It pulls to 6800 pretty easily. From 6000-6800, I only loose 4rwhp.
Here is my dyno graph with the TR224 cam/stock heads and Comp 918s:
Thunder 224 cam
It pulls to 6800 pretty easily. From 6000-6800, I only loose 4rwhp.
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From: Rockland County, NY
Re: In your opinion, does this look like a valvespring problem? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Jason99T/A:
<strong>Phil, there is defintely something wrong in the upper RPMs. What lifters and pushrods are you using? Was this occuring on every single pull? Were the 941s brand new when they were installed on your car? How many miles on the setup?
Here is my dyno graph with the TR224 cam/stock heads and Comp 918s:
Thunder 224 cam
It pulls to 6800 pretty easily. From 6000-6800, I only loose 4rwhp.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Jason my dyno pulls look the same up top on every single run. I'm using stock lifters and I think the pushrods are 7.25" with lash caps. The springs had about 3k miles on them when I installed the heads and I've since put on another 9k. However like i said, I had the same problem even when they were first on my car.
<strong>Phil, there is defintely something wrong in the upper RPMs. What lifters and pushrods are you using? Was this occuring on every single pull? Were the 941s brand new when they were installed on your car? How many miles on the setup?
Here is my dyno graph with the TR224 cam/stock heads and Comp 918s:
Thunder 224 cam
It pulls to 6800 pretty easily. From 6000-6800, I only loose 4rwhp.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Jason my dyno pulls look the same up top on every single run. I'm using stock lifters and I think the pushrods are 7.25" with lash caps. The springs had about 3k miles on them when I installed the heads and I've since put on another 9k. However like i said, I had the same problem even when they were first on my car.
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Re: In your opinion, does this look like a valvespring problem? Jason are you thinking that my valvetrain geometry may not be right, like my pushrods are too short or something?
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Re: In your opinion, does this look like a valvespring problem? I think it is definitely springs or fuel related.
You have also run a best of 11.5 and a best mph of 121mph in the car too correct?
Something doesnt look right there and I bet it is spring related. I would go with the K750's and measure everything up when you put them in. I would also have Mikey at Rapid Motorsports look at the car and do the spring install if he is close to you.
Cheers,
Chris
You have also run a best of 11.5 and a best mph of 121mph in the car too correct?
Something doesnt look right there and I bet it is spring related. I would go with the K750's and measure everything up when you put them in. I would also have Mikey at Rapid Motorsports look at the car and do the spring install if he is close to you.
Cheers,
Chris