355 LE dyno tune this Friday...Guess my numbers
03-25-2008, 07:53 PM
#1
355 LE dyno tune this Friday...Guess my numbers Bluecat in eastern KY will be dyno tuning my new 355 this Friday. Right now with my mailorder tune it is crazy fast and I have yet to really feel the motor peak, although I have been shifting at only 6300 RPM. I am getting knock retard too on top of it all.
See my sig and guess my RWHP and RWTQ and please pass along any tips that might help out.
See my sig and guess my RWHP and RWTQ and please pass along any tips that might help out.
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03-26-2008, 07:39 AM
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That cam is only 224 duration and should make peak HP at about 6250 or so.
Some larger LT headers with true duals would help over the RK Mids and Borla cat back exhaust. make sure and have the cut out open.
Going thru the 9" with a HEAVY posi unit, I would say 380 RWHP/370 RWTQ.
Lloyd
Some larger LT headers with true duals would help over the RK Mids and Borla cat back exhaust. make sure and have the cut out open.
Going thru the 9" with a HEAVY posi unit, I would say 380 RWHP/370 RWTQ.
Lloyd
03-29-2008, 08:27 AM
#14
UPDATE.
Spent 10 hours with Bluecat yesterday and I must preface by saying his attention to detail, knowledge on fuel injected GM motors and dedication and commitment to me to get the most power out of my motor was absolutely second to NONE.
By and large my motor was very sound and receptive to changes. It threw no major screwballs at Phil in the way that some LT1's do. He spent more time precisely dialing in the tune cell by cell and block by block as a result of the motor cooperating from square one. The one major point we had to address was knock retard which has been killing me on the mail order tune.
We spent 6 hours (with breaks) only working on NON-WOT road tuning. We learned right off the bat that my mail order tune was running way lean under these conditions according to the wide band O2 sensor that he installed. We then mad a several short non spirited drives while logging everything on his laptop using Data master. After each drive he would meticulously dissect the data logs and make changes again block by block. The motor is now easier to drive and has significantly less light throttle surging across the board than before. The only headache we ran into was trying to address the 1500 RPM light throttle surge using a closed loop tune. The motor wants more gas in this area but the PCM in closed loop wont cooperate with out affecting everything else. However we did cure it with an open loop tune which I can load up anytime if I feel the need. We both agree its the cam size causing this, however its just a minor nuisance and not really an issue.
Now for the fun stuff, so on to the WOT dyno tuning we go. Phil has a inertial Dynojet that he does his tuning on. We spent a couple of hours here and made around 8 pulls total. The baseline pull was very much in the ball park so again he just concentrated on precision tuning just like before.
All numbers SAE.
Baseline pull:
370 RWHP 350 RWTQ
Best pull:
375 RWHP 355 RWTQ
Best (cutout closed) pull:
371 RWHP 351 RWTQ
Best pull (CAI and elbow removed)
381 RWHP and 357 RWTQ
All this through the new Midwest 9" rear and RK sport Mid length headers BTW.
The thing we noticed on the charts is power and torque are great right up to 6000 RPM then it falls off like a rock. Shift point is 6200 RPM right now. Again it does not slightly roll off, it falls like **** out of a boot.
We think there may be some valve float due to the fast ramps on my LE 1.5 high lift camshaft or maybe the beehive valve springs are not quite getting the job done. I have a brand new set of COMP dually LS1 valve springs with titanium retainers sitting in the closet right now. I am not really interested in twisting the motor any higher, but if anything is to gain under the fall off then it would be worth researching.
During the drive home I did some hard launches to feel out the new tune. Before the tune, first gear was almost useless. Now after the tune first gear is totally useless since the PCM is not pulling timing due to false knock. I then did a nasty burnout to get the tires hot as to get a better feel to where I was. Dumped the clutch at 3K RPM and the tires hooked hard and I hit the 1st gear shift point so fast I wasn't ready for it. 2nd gear came up fast as well. 3rd and 4th gear power is brutal compared to my old motor. All this with ZERO knock retard.
There is absolutely NO doubt that my LT1 is many times more powerful on Phils tune than before. In conclusion, I wanted my new LT1 to rev to 6300 RPM or so to ensure great street manners, great reliability, decent mileage and deep 12 second ET's to boot. Clearly I think I am there.
Charts will post ASAP. Check back with me.
Spent 10 hours with Bluecat yesterday and I must preface by saying his attention to detail, knowledge on fuel injected GM motors and dedication and commitment to me to get the most power out of my motor was absolutely second to NONE.
By and large my motor was very sound and receptive to changes. It threw no major screwballs at Phil in the way that some LT1's do. He spent more time precisely dialing in the tune cell by cell and block by block as a result of the motor cooperating from square one. The one major point we had to address was knock retard which has been killing me on the mail order tune.
We spent 6 hours (with breaks) only working on NON-WOT road tuning. We learned right off the bat that my mail order tune was running way lean under these conditions according to the wide band O2 sensor that he installed. We then mad a several short non spirited drives while logging everything on his laptop using Data master. After each drive he would meticulously dissect the data logs and make changes again block by block. The motor is now easier to drive and has significantly less light throttle surging across the board than before. The only headache we ran into was trying to address the 1500 RPM light throttle surge using a closed loop tune. The motor wants more gas in this area but the PCM in closed loop wont cooperate with out affecting everything else. However we did cure it with an open loop tune which I can load up anytime if I feel the need. We both agree its the cam size causing this, however its just a minor nuisance and not really an issue.
Now for the fun stuff, so on to the WOT dyno tuning we go. Phil has a inertial Dynojet that he does his tuning on. We spent a couple of hours here and made around 8 pulls total. The baseline pull was very much in the ball park so again he just concentrated on precision tuning just like before.
All numbers SAE.
Baseline pull:
370 RWHP 350 RWTQ
Best pull:
375 RWHP 355 RWTQ
Best (cutout closed) pull:
371 RWHP 351 RWTQ
Best pull (CAI and elbow removed)
381 RWHP and 357 RWTQ
All this through the new Midwest 9" rear and RK sport Mid length headers BTW.
The thing we noticed on the charts is power and torque are great right up to 6000 RPM then it falls off like a rock. Shift point is 6200 RPM right now. Again it does not slightly roll off, it falls like **** out of a boot.
We think there may be some valve float due to the fast ramps on my LE 1.5 high lift camshaft or maybe the beehive valve springs are not quite getting the job done. I have a brand new set of COMP dually LS1 valve springs with titanium retainers sitting in the closet right now. I am not really interested in twisting the motor any higher, but if anything is to gain under the fall off then it would be worth researching.
During the drive home I did some hard launches to feel out the new tune. Before the tune, first gear was almost useless. Now after the tune first gear is totally useless since the PCM is not pulling timing due to false knock. I then did a nasty burnout to get the tires hot as to get a better feel to where I was. Dumped the clutch at 3K RPM and the tires hooked hard and I hit the 1st gear shift point so fast I wasn't ready for it. 2nd gear came up fast as well. 3rd and 4th gear power is brutal compared to my old motor. All this with ZERO knock retard.
There is absolutely NO doubt that my LT1 is many times more powerful on Phils tune than before. In conclusion, I wanted my new LT1 to rev to 6300 RPM or so to ensure great street manners, great reliability, decent mileage and deep 12 second ET's to boot. Clearly I think I am there.
Charts will post ASAP. Check back with me.
Last edited by wrd1972; 03-29-2008 at 09:15 AM.
03-30-2008, 08:35 AM
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Those are some great numbers, is Bluecat anywhere near Rochester NY? I need a tune bad too and I know I am pretty certain i am getting timing pulled as well from false knock.
03-30-2008, 06:19 PM
#20
Guys,
I am chasing down this valve float issue at 6K RPM wher the power just falls off the mountain. It is essential that I fix this before hitting the track.
I am running PAC 1218 beehives that are set at 1.780" install height. Lloyd told me to set them at 1.750" for best results. The beehives have pressures of 130/330 pounds.
I also have a full set of Comp 921 dual coils with titanium retainers sitting in the closet collecting dust. These have a pressures of 135/400 pounds.
My GM lifters are set at 1/4" past zero lash.
It appears that its the very fast ramps of the cam that are the root cause of the float and I have to work to that. I am planning on just installing the Comp 921's rather than reset the beehives since all that crap has to come off anyway.
Any thoughts?
I am chasing down this valve float issue at 6K RPM wher the power just falls off the mountain. It is essential that I fix this before hitting the track.
I am running PAC 1218 beehives that are set at 1.780" install height. Lloyd told me to set them at 1.750" for best results. The beehives have pressures of 130/330 pounds.
I also have a full set of Comp 921 dual coils with titanium retainers sitting in the closet collecting dust. These have a pressures of 135/400 pounds.
My GM lifters are set at 1/4" past zero lash.
It appears that its the very fast ramps of the cam that are the root cause of the float and I have to work to that. I am planning on just installing the Comp 921's rather than reset the beehives since all that crap has to come off anyway.
Any thoughts?