93lt1 blower. 510 rwhp. less spark advance made more power, esp. down low
09-30-2012, 08:21 PM
#1
Race Director
Thread Starter
93lt1 blower. 510 rwhp. less spark advance made more power, esp. down low
Just wanted to post here.
I ran my car at the dyno last thursday night. I made 510 rwhp/ at 5600 rpm. I would have made even more power if I spun higher. However, Im not sure Im willing to do that on a stock bottom end.
I had another run where I made 505 rwhp@ 5350 RPM / 495 rwTQ. I estimate it would have made 520 rwhp if I spun it up to 5800 rpm.
Again, my stock bottom end kind of makes me nervous spinning it up that high.
What is really impressive is that I picked up low end power from the 2600 rpm to 4000 rpm range by reducing timing. yes, thats not a typo. Reducing timing from the following numbers to allowed me to pick up power right then and there. I think thats a characteristic of AFR heads.
A quick thanks to CF user 'bogor' for steering me in that direction (of lower timing = more power).
Heres the 510 rwhp and 505 rwhp runs.
Heres my mod list:
93 lt1 6spd
-procharger p600b w/ 2.75" pulley making 12 psi boost at 5500 rpm (5 psi @ 3000; 7.5psi @ 4000, 10psi@5000)
-blowerworks custom 8 rib dedicated drive system bracket & ATI superdamper 6+8 crank pulley (from blowerworks)
-60 lb/hr fuel injectors (from blowerworks)
-GSL392 pump feeding walbro 340 (255 l/hr pump) (from blowerworks)
-50/50 meth water blowerworks alky system (15 GPH nozzle)
-moates ostrich w/ blowerworks basetune (tune modified by me on tunerpro software)
-AFR 195 comp eliminator heads w/ 61cc (lowered compression from 10.5:1 to 9.6:1)
-TPIS long tube 1 3/4" headeres
-custom x-pipe & dyno max superturbo mufflers
-lloyd elliot 224/236 114 LSA cam w/ 1.6:1 roller rockers
-lloyd elliot custom ported lt1 intake manifold
-lt4 ED timing chain kit
-SPEC stage 3+ clutch and louis fidanza lightweight alum flywheel.
Heres a comparison of my best last year (same blower, but did not have the AFR comp elim 195 heads, x-pipe, LE ported intake or the LE 224/236 cam. I just had ported lt1 heads, and a hotcam. ALso was running 3" blower pulley but boost curve was the same since the setup was not as free-flowing as it is now). It is amazing that I did not give up anything down low inspite of the fact I increased my head size, cam size, and lowered compression ratio on top of that. This is truly awesome brutal torque that makes the car very fun to drive. Essentially 400 rwTQ at 3000 rpm.
I ran the car at an Auto X today and everything ran great. It was tough to put the power down (especially when the track got moist) even on P315/35R17's slicks, but that was what I expected. I could usually get traction (Except when track got wet), but couldnt handle the 'speed' for the tight course. Again, thats a good thing.
I ran my car at the dyno last thursday night. I made 510 rwhp/ at 5600 rpm. I would have made even more power if I spun higher. However, Im not sure Im willing to do that on a stock bottom end.
I had another run where I made 505 rwhp@ 5350 RPM / 495 rwTQ. I estimate it would have made 520 rwhp if I spun it up to 5800 rpm.
Again, my stock bottom end kind of makes me nervous spinning it up that high.
What is really impressive is that I picked up low end power from the 2600 rpm to 4000 rpm range by reducing timing. yes, thats not a typo. Reducing timing from the following numbers to allowed me to pick up power right then and there. I think thats a characteristic of AFR heads.
A quick thanks to CF user 'bogor' for steering me in that direction (of lower timing = more power).
Heres the 510 rwhp and 505 rwhp runs.
Heres my mod list:
93 lt1 6spd
-procharger p600b w/ 2.75" pulley making 12 psi boost at 5500 rpm (5 psi @ 3000; 7.5psi @ 4000, 10psi@5000)
-blowerworks custom 8 rib dedicated drive system bracket & ATI superdamper 6+8 crank pulley (from blowerworks)
-60 lb/hr fuel injectors (from blowerworks)
-GSL392 pump feeding walbro 340 (255 l/hr pump) (from blowerworks)
-50/50 meth water blowerworks alky system (15 GPH nozzle)
-moates ostrich w/ blowerworks basetune (tune modified by me on tunerpro software)
-AFR 195 comp eliminator heads w/ 61cc (lowered compression from 10.5:1 to 9.6:1)
-TPIS long tube 1 3/4" headeres
-custom x-pipe & dyno max superturbo mufflers
-lloyd elliot 224/236 114 LSA cam w/ 1.6:1 roller rockers
-lloyd elliot custom ported lt1 intake manifold
-lt4 ED timing chain kit
-SPEC stage 3+ clutch and louis fidanza lightweight alum flywheel.
Heres a comparison of my best last year (same blower, but did not have the AFR comp elim 195 heads, x-pipe, LE ported intake or the LE 224/236 cam. I just had ported lt1 heads, and a hotcam. ALso was running 3" blower pulley but boost curve was the same since the setup was not as free-flowing as it is now). It is amazing that I did not give up anything down low inspite of the fact I increased my head size, cam size, and lowered compression ratio on top of that. This is truly awesome brutal torque that makes the car very fun to drive. Essentially 400 rwTQ at 3000 rpm.
I ran the car at an Auto X today and everything ran great. It was tough to put the power down (especially when the track got moist) even on P315/35R17's slicks, but that was what I expected. I could usually get traction (Except when track got wet), but couldnt handle the 'speed' for the tight course. Again, thats a good thing.
Last edited by dizwiz24; 09-30-2012 at 08:24 PM.
09-30-2012, 08:35 PM
#2
Race Director
Thread Starter
Heres what I did to the timing:
This new reduced timing gave as much as a 14 rwTQ improvement at low RPM !!!
Old timing in (), new timing next to it
RPM
2400: (30) 26
2800: (31) 28
3200: (30) 27
3600: (27) 24
4000: (24) 22
4500: (22) 20
5000: (22) 20
5500: (22) 20
Heres a graph of what effect the timing had.
Run 1993.027 is the effect of the timing in ( )
Run 1993.029 is the effect of the timing next to it (essentially 3 or 4 degrees less).
Run 1993.28 is timing set in between (1 to 2 degrees less than the original timing)
Note run 1993.029 was where the reduction in timing paid off.
Look at the green line and the TQ i picked up down low. I feel this every time I drive the car.
Also, notice that reducing the timing up top cost me some power. So I kept that timing in place (of run 28) up top and reduced timing down low (like in run 29) for best results.
This new reduced timing gave as much as a 14 rwTQ improvement at low RPM !!!
Old timing in (), new timing next to it
RPM
2400: (30) 26
2800: (31) 28
3200: (30) 27
3600: (27) 24
4000: (24) 22
4500: (22) 20
5000: (22) 20
5500: (22) 20
Heres a graph of what effect the timing had.
Run 1993.027 is the effect of the timing in ( )
Run 1993.029 is the effect of the timing next to it (essentially 3 or 4 degrees less).
Run 1993.28 is timing set in between (1 to 2 degrees less than the original timing)
Note run 1993.029 was where the reduction in timing paid off.
Look at the green line and the TQ i picked up down low. I feel this every time I drive the car.
Also, notice that reducing the timing up top cost me some power. So I kept that timing in place (of run 28) up top and reduced timing down low (like in run 29) for best results.
Last edited by dizwiz24; 10-03-2012 at 07:45 PM.
10-01-2012, 11:45 AM
#5
Race Director
Thread Starter
I want to add something oddball that I noticed:
I was also recording inlet temps (after meth/water injection) at the throttle body opening.
Despite injecting 50/50 meth/water at 15 gal/hr nozzle, I saw as high as 115F temp at 12 psi boost...and this was on a 65F day.
I wonder what my temp was directly at the blower discharge?
or is the meth/water not helping to cool down the charge as much as I thought it would?
Ive heard people on C5 FI say that meth (probably 100% meth) cools down their IAT's as much as 20F below ambient temperature! at similar boost level with p1-sc (A similar blower to p600b).
BTW, my car's IAT probe is relocated outside the intake duct to sense ambient air temperature, not air charge air temp - per advice from Greg @ blowrworks.
I was also recording inlet temps (after meth/water injection) at the throttle body opening.
Despite injecting 50/50 meth/water at 15 gal/hr nozzle, I saw as high as 115F temp at 12 psi boost...and this was on a 65F day.
I wonder what my temp was directly at the blower discharge?
or is the meth/water not helping to cool down the charge as much as I thought it would?
Ive heard people on C5 FI say that meth (probably 100% meth) cools down their IAT's as much as 20F below ambient temperature! at similar boost level with p1-sc (A similar blower to p600b).
BTW, my car's IAT probe is relocated outside the intake duct to sense ambient air temperature, not air charge air temp - per advice from Greg @ blowrworks.
Last edited by dizwiz24; 10-14-2012 at 10:20 PM.
10-01-2012, 04:42 PM
#7
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Despite injecting 50/50 meth/water at 15 gal/hr nozzle, I saw as high as 140F temp at 12 psi boost...and this was on a 65F day.
I wonder what my temp was directly at the blower discharge?
or is the meth/water not helping to cool down the charge as much as I thought it would?
