SN95 5.3 TH400 3.27 build thread - 10.88/134.86 - NOW LQ9
09-07-2015, 08:32 AM
#202
Barrett do you have a part#? I'm using the truck alternator - the smaller 105a unit. Although, the logger shows the voltage dipping during the shift. If it was overspinning, wouldnt I lose voltage at higher rpms? To me it seems its more of and issue with the alternator spinning at X rpm following engine rpm and then there is a sudden 1000+rpm engine drop and the alternator wants to keep going, causing a momentary loss of alt. control.
09-07-2015, 12:41 PM
#203
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Looks like it's probably slipping the belt on the shifts. But even for that the voltage is only dropping down to 13 which I don't see as a big issue. I've yet to here of any issues with alternator overspinning, doesn't mean it's not possible however.
09-08-2015, 12:37 AM
#206
Well the reason why I asked is because I have experience a little alt belt slip on my race truck due to the engine twisting. Thats another story. Anyway, I have a Holley data log I'd like to show you, but I don't have the software on this computer. I'll get it done and show you what I'm talking about.
09-08-2015, 05:47 AM
#207
Well the reason why I asked is because I have experience a little alt belt slip on my race truck due to the engine twisting. Thats another story. Anyway, I have a Holley data log I'd like to show you, but I don't have the software on this computer. I'll get it done and show you what I'm talking about.
Although, lotta folks here spinning their motor very high and dont seem to have issues. I dont even know if I have an issue lol!
09-09-2015, 12:16 AM
#208
My issue has nothing to do with the mount or pulley alignment. The engine is mounted with a 2 piece .250" aluminum motor plate and a .125" steel mid plate that is very long to stretch the width of the truck frame. I was running an engine limiter only on the right side of the motor. I was have strange **** happen on the left side (crank sensor touching down and alt belt trouble). When I would come off the transbrake the motor would actually twist as if you where looking down from above. The left side was going backwards flexing the plates. I'll be adding a limiter to the left side as well and it should keep everything in line.
10-03-2015, 04:36 PM
#209
We'll , my WOT lack of charge issue came back. After about 6080 rpm the alternator shuts off and when I need voltage the most (wot driving 2 pumps, fan, meth pump, coils etc) I lose voltage fast.
Turns out I was overspeeding the alternator. "They" say you shouldn't really spin an alternator past 16,000-18,000 rpms. We'll the truck alternator are like 2.2" b/c the trucks idle at like 550 rpm. So 7.5" crank pulley/2.2" = 3.4 ratio, x 6000+ rpm shift points = 20,400 min alternator speed (more like 21-22,000). I fixed the issue with a Texas Speed 2.75" pulley in case anybody was wondering. And charges just fine at idle with the slightly higher idle settings we use b/c of the cams.
Now I'm wondering if low system voltage had something to do with the demise of the other engine, or maybe that's why it never ran as strong????
Turns out I was overspeeding the alternator. "They" say you shouldn't really spin an alternator past 16,000-18,000 rpms. We'll the truck alternator are like 2.2" b/c the trucks idle at like 550 rpm. So 7.5" crank pulley/2.2" = 3.4 ratio, x 6000+ rpm shift points = 20,400 min alternator speed (more like 21-22,000). I fixed the issue with a Texas Speed 2.75" pulley in case anybody was wondering. And charges just fine at idle with the slightly higher idle settings we use b/c of the cams.
Now I'm wondering if low system voltage had something to do with the demise of the other engine, or maybe that's why it never ran as strong????
10-03-2015, 04:42 PM
#210
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Hmm...I haven't paid attention to it specifically but I haven't noticed any voltage loss at 6400 rpm or any changes in fueling. I may log voltage at the track next time to see if this is real. You may have electrical gremlins.
10-03-2015, 04:42 PM
#211
And...
I took the PTC converter out as I feel its too tight for what I'm doing. I know, its the exact opposite of what most folks do, but I think I was about 100-200 hp short of what that sucker needed to really sing. I went back with a 450.00 Trans Specialties 10" "low stall" unit and it feels better already up top especially from 2-3rd at wot. Surprisingly, still getting a ~900 rpm drop vs the PTC 1100-1200 drop, but feels noticeable better in the sense that the engine is not just flatlining in 3rd. I does feel slightly looser at part throttle than the PTC which sucks, but not THAT different.
Hope to see what the new combo can do next Wed or Fri at the track. I will have a self-imposed 16psi max boost setting. Gotta be careful with the Gen III rods as you all know
I took the PTC converter out as I feel its too tight for what I'm doing. I know, its the exact opposite of what most folks do, but I think I was about 100-200 hp short of what that sucker needed to really sing. I went back with a 450.00 Trans Specialties 10" "low stall" unit and it feels better already up top especially from 2-3rd at wot. Surprisingly, still getting a ~900 rpm drop vs the PTC 1100-1200 drop, but feels noticeable better in the sense that the engine is not just flatlining in 3rd. I does feel slightly looser at part throttle than the PTC which sucks, but not THAT different.
Hope to see what the new combo can do next Wed or Fri at the track. I will have a self-imposed 16psi max boost setting. Gotta be careful with the Gen III rods as you all know
10-04-2015, 09:29 AM
#212
We'll , my WOT lack of charge issue came back. After about 6080 rpm the alternator shuts off and when I need voltage the most (wot driving 2 pumps, fan, meth pump, coils etc) I lose voltage fast.
Turns out I was overspeeding the alternator. "They" say you shouldn't really spin an alternator past 16,000-18,000 rpms. We'll the truck alternator are like 2.2" b/c the trucks idle at like 550 rpm. So 7.5" crank pulley/2.2" = 3.4 ratio, x 6000+ rpm shift points = 20,400 min alternator speed (more like 21-22,000). I fixed the issue with a Texas Speed 2.75" pulley in case anybody was wondering. And charges just fine at idle with the slightly higher idle settings we use b/c of the cams.
Now I'm wondering if low system voltage had something to do with the demise of the other engine, or maybe that's why it never ran as strong????
Turns out I was overspeeding the alternator. "They" say you shouldn't really spin an alternator past 16,000-18,000 rpms. We'll the truck alternator are like 2.2" b/c the trucks idle at like 550 rpm. So 7.5" crank pulley/2.2" = 3.4 ratio, x 6000+ rpm shift points = 20,400 min alternator speed (more like 21-22,000). I fixed the issue with a Texas Speed 2.75" pulley in case anybody was wondering. And charges just fine at idle with the slightly higher idle settings we use b/c of the cams.
Now I'm wondering if low system voltage had something to do with the demise of the other engine, or maybe that's why it never ran as strong????
I swapped to a mandrel drive so I could set pulley sizes to keep from killing alternators and having low voltage at rpm
10-07-2015, 09:23 PM
#215
Made a couple of passes at the track tonite...very crowded and a lot of oils downs, so just 2 runs.
1st run leaving with no boost was 1.86/103.8/10.9/130.25. This was with about 15.5 psi in top gear and 12* of timing.
2nd run I was able to muster 1.5 psi leaving and did 1.77/106.3/10.5/133.3, with about 16.5 psi in top gear and 14* of timing.
Very pleased with how it ran, and the new Trans Spec. converter is showing 8.5% slippage up top which is surprising for a $425.00 converter and the car feels better now in top gear vs the PTC. Just 93 octane tonight, no meth injection either. IAT's barely above where they start...around 110*
Just wondering if I should go with the ls6 cam again or maybe the ls9 b/c my first 5.3 did run 134 mph, so why go with more cam than necessary right? This time around I did have a full 2.5" exhaust though.
All in all a good night!!!
1st run leaving with no boost was 1.86/103.8/10.9/130.25. This was with about 15.5 psi in top gear and 12* of timing.
2nd run I was able to muster 1.5 psi leaving and did 1.77/106.3/10.5/133.3, with about 16.5 psi in top gear and 14* of timing.
Very pleased with how it ran, and the new Trans Spec. converter is showing 8.5% slippage up top which is surprising for a $425.00 converter and the car feels better now in top gear vs the PTC. Just 93 octane tonight, no meth injection either. IAT's barely above where they start...around 110*
Just wondering if I should go with the ls6 cam again or maybe the ls9 b/c my first 5.3 did run 134 mph, so why go with more cam than necessary right? This time around I did have a full 2.5" exhaust though.
All in all a good night!!!
10-18-2015, 05:21 PM
#217
Not sure but from what I read their weak. But why bother when you can get a 8.8 which is a direct bolt in and very strong. I paid 150.00 for mine with 3.27 gears and a posi unit which I replaced with a new Ford Racing 31 spline Cobra unit for like 250.00 and its still hanging in there.
10-18-2015, 06:17 PM
#218
Not sure but from what I read their weak. But why bother when you can get a 8.8 which is a direct bolt in and very strong. I paid 150.00 for mine with 3.27 gears and a posi unit which I replaced with a new Ford Racing 31 spline Cobra unit for like 250.00 and its still hanging in there.
10-28-2015, 04:04 PM
#219
Update:
Picked up a 02 LQ9 complete for 1000.00. And my gamble paid off - this motor has the floating rods
Sold off everything and it was 50.00 to upgrade to this engine. I really just wanted the stronger rods for boost.
New combo will look like this:
-02 LQ9 (100K+)...looks good inside, no sludge, metal etc, good compress.
-China head studs
-BTR dual springs
-BTR "4.8 Stage II" turbo cam, 218/223 112lsa
-TFS pushrods.
I really like small cams but its hard to give up some of the gains the bigger ones seem to give, so I split the difference.
Hopefully she'll kick some ***.
Picked up a 02 LQ9 complete for 1000.00. And my gamble paid off - this motor has the floating rods
Sold off everything and it was 50.00 to upgrade to this engine. I really just wanted the stronger rods for boost.New combo will look like this:
-02 LQ9 (100K+)...looks good inside, no sludge, metal etc, good compress.
-China head studs
-BTR dual springs
-BTR "4.8 Stage II" turbo cam, 218/223 112lsa
-TFS pushrods.
I really like small cams but its hard to give up some of the gains the bigger ones seem to give, so I split the difference.
Hopefully she'll kick some ***.
10-28-2015, 06:24 PM
#220
I'm sure that cam will work great, the only real difference a bigger cam gives you, is extra rpm - which gives free hp.
I LOVE big cams, but if the WHOLE combo is not sett up for the rpm range your cam works at. ...it will be slower in spite of the extra hp
I LOVE big cams, but if the WHOLE combo is not sett up for the rpm range your cam works at. ...it will be slower in spite of the extra hp