355 LE Dyno tune this Friday...Guess my numbers
03-29-2008, 12:29 PM
#46
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I was only 1hp off. 
I'm supprised the torque is so low though.
And if you are getting valve float get that fixed, unless you want to destroy your new motor. I got valvefloat with that cam back when I was running it so I'm not supprised at all if you are getting some.
I'm supprised the torque is so low though.And if you are getting valve float get that fixed, unless you want to destroy your new motor. I got valvefloat with that cam back when I was running it so I'm not supprised at all if you are getting some.
03-29-2008, 12:54 PM
#47
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Switching to Lt's will make a big difference in the low and mid range and will probably bump up those torque numbers. They will also make it drive even better and smooth it out. I know when I switched from SLP to Pacesetter the difference was night and day.
As far as valve float find out the pressures of the springs you're running and see if you think they are high enough. If not then maybe go a little stiffer and see if it helps. Springs are hard to choose sometimes, you want a spring strong enough to control the weight and acceleration of the valve, but not so strong that it robs power from the valvetrain. It's a fine line.
As far as valve float find out the pressures of the springs you're running and see if you think they are high enough. If not then maybe go a little stiffer and see if it helps. Springs are hard to choose sometimes, you want a spring strong enough to control the weight and acceleration of the valve, but not so strong that it robs power from the valvetrain. It's a fine line.
03-29-2008, 01:04 PM
#48
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Join Date: Oct 2007
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I had the Comp 26918 beehives on my car with the XFI268 cam and would run into serious valve float around 6200rpm. As the springs became weaker my power strarted dropping off above 5000rpm from previous dyno runs.
I just replaced the springs with the Manley beehives with 150# on the seat. My power came right back and I can now rev the motor to at least 6500rpm with no valve float.
Also the power holds on until that point and does not drop off.
I just replaced the springs with the Manley beehives with 150# on the seat. My power came right back and I can now rev the motor to at least 6500rpm with no valve float.
Also the power holds on until that point and does not drop off.
03-29-2008, 01:10 PM
#49
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Location: Ocala, Florida
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I never did on my old setup.
I was going to put on pac1518's on but they are the same pressure as the 918's so I don't see that doing anything. Comps new 918's have a higher spring rate so that might be something to look into. Did you check the spring installed height? Mine varied from 1.8-1.75" on my LE2 heads, and Javiers were at 1.80" even though they reccomend installing them at 1.75" so yours might be off too.
I was going to put on pac1518's on but they are the same pressure as the 918's so I don't see that doing anything. Comps new 918's have a higher spring rate so that might be something to look into. Did you check the spring installed height? Mine varied from 1.8-1.75" on my LE2 heads, and Javiers were at 1.80" even though they reccomend installing them at 1.75" so yours might be off too.
03-29-2008, 01:12 PM
#50
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Location: Ocala, Florida
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Switching to Lt's will make a big difference in the low and mid range and will probably bump up those torque numbers. They will also make it drive even better and smooth it out. I know when I switched from SLP to Pacesetter the difference was night and day.
As far as valve float find out the pressures of the springs you're running and see if you think they are high enough. If not then maybe go a little stiffer and see if it helps. Springs are hard to choose sometimes, you want a spring strong enough to control the weight and acceleration of the valve, but not so strong that it robs power from the valvetrain. It's a fine line.
As far as valve float find out the pressures of the springs you're running and see if you think they are high enough. If not then maybe go a little stiffer and see if it helps. Springs are hard to choose sometimes, you want a spring strong enough to control the weight and acceleration of the valve, but not so strong that it robs power from the valvetrain. It's a fine line.
03-29-2008, 01:36 PM
#51
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Okay guys.
I am running PAC 1218's on the LE2 heads.
Specs are 130# on the seat and 318# open.
I am holding in my hands now my brand new set of Comp 921'a w/ titanium retainers.
Specs are 135# on the seat and 400# open.
Obviously the 921's are a stiffer spring which should do a better job at not floating the valves. Are these springs overkill or is there something more practical. These 1218's are not getting the job done?
I am running PAC 1218's on the LE2 heads.
Specs are 130# on the seat and 318# open.
I am holding in my hands now my brand new set of Comp 921'a w/ titanium retainers.
Specs are 135# on the seat and 400# open.
Obviously the 921's are a stiffer spring which should do a better job at not floating the valves. Are these springs overkill or is there something more practical. These 1218's are not getting the job done?
03-29-2008, 01:44 PM
#52
are you sure its the springs?
i have the same heads, same springs, and a bigger cam. i have not had it on the dyno yet but i can tell you for sure when i let off at 6600 it is still pulling.
i do realize that cam uses more aggressive steeper lobes than mine, and i dont know enough about cams to know if that is what would cause that
i have the same heads, same springs, and a bigger cam. i have not had it on the dyno yet but i can tell you for sure when i let off at 6600 it is still pulling.
i do realize that cam uses more aggressive steeper lobes than mine, and i dont know enough about cams to know if that is what would cause that
03-29-2008, 01:51 PM
#53
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are you sure its the springs?
i have the same heads, same springs, and a bigger cam. i have not had it on the dyno yet but i can tell you for sure when i let off at 6600 it is still pulling.
i do realize that cam uses more aggressive steeper lobes than mine, and i dont know enough about cams to know if that is what would cause that
i have the same heads, same springs, and a bigger cam. i have not had it on the dyno yet but i can tell you for sure when i let off at 6600 it is still pulling.
i do realize that cam uses more aggressive steeper lobes than mine, and i dont know enough about cams to know if that is what would cause that
The power peaks at 6K RPM then falls right off the mountain. I cant imagine the headers or anything else showing this kind of exrtreme out of nowhere behavior, but I am open to suggestions. PAC says the 1218 beehive is good up to .600, I am a tad above that already.
Last edited by wrd1972; 03-29-2008 at 03:18 PM.
03-29-2008, 02:58 PM
#55
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Location: Lantana, TX
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It's not a fine line for a street car. Having an oversprung setup is ALOT better than an undersprung setup, expecially with a street driven vehicle. I would gladly give up 1-2hp to be able to miss a shift without blowing my motor, or having the springs give up a few lbs over time and start running into valve float issues.
Yes, I know these are the springs that Lloyd/Bret recommend for their setups, but do you think they could offer such good prices and sell so many if they ran Isky springs which cost twice as much as Comp springs?
03-29-2008, 04:57 PM
#56
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Location: Jackstandican
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where's the graph? what rpm did the numbers peak?
if those numbers hold true you should be real close to the 12.0 range depending on gearing and such. 3.90's just may be perfect depending on your power peak. what's the race weight?
if those numbers hold true you should be real close to the 12.0 range depending on gearing and such. 3.90's just may be perfect depending on your power peak. what's the race weight?
Last edited by SS RRR; 03-29-2008 at 05:00 PM.
03-29-2008, 05:01 PM
#57
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Posts: 1,444
Actually, based on what Wrd said, we pretty much do.
His sounds identical to JoeB's LE1N20 grind.
Jerry always puts on a good show 
I sure hope we get to do Jeremy's 21-car burnout salute.
His sounds identical to JoeB's LE1N20 grind.
I sure hope we get to do Jeremy's 21-car burnout salute.
03-29-2008, 05:43 PM
#58
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Posts: 459
Not sure what the LE1.5 cam specs are VS my LE1HL, but yeah with LTs,
DRs/Skinnies and a little suspension work you can get a full-weight car with a 275lbs driver into the 11s.
Should have numbers from the 355 setup soon.
Ask me how I know (and for the record, both wheels are up LOL)
I wish I had a pic of of my 1.588 lauch, but this 1.603 looks about the same.
DRs/Skinnies and a little suspension work you can get a full-weight car with a 275lbs driver into the 11s.
Should have numbers from the 355 setup soon.
Ask me how I know
(and for the record, both wheels are up LOL)I wish I had a pic of of my 1.588 lauch, but this 1.603 looks about the same.
03-29-2008, 06:08 PM
#59
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Still waiting on the tuner to send them to me. Race weight is going to be heavy at around 3900 pounds. Tuner stated that 3.90 is looking like the best gear for street tires or 255-50-16 ET street radials.