396ci LT4, YSI and 15lb of boost dyno result :(
#1
396ci LT4, YSI and 15lb of boost dyno result :(
Hi,
I need you advice. I went to the dyno shop and I was disappointed with the result- I dont know if I should but I expected more power- .The engine made 671rwhp @ 6500 rpm and 583rwtq @ 5400 rpm. That's with 15psi boost,_ YSI with 2.75'' pulley and 7'' crank pulley, 95 octane fuel and 35 deg of total timing air/fuel ratio was 11.8- 12.2 . Charged air temp was 24 deg C.I need to know what I did wrong or is it the engine combo.your suggestion will be appreciated. Thanks.
engine specs,
- Vortech supercharger- YSi-trim.
- Vortech aftercooler.
- 396 ci, 8.0:1 Comp
- AFR 227 heads part# 1076
- Victor JR single plane intake
- LS1 90mm TB
- Cam: hydraulic roller Duration@.050 248/254 lift .562/580 lobe 114.0
- JESEL shaft mount rockers 1.5
- AFR hydra rev
- Hooker Long tube headers
- FAST Classic ecu.
I need you advice. I went to the dyno shop and I was disappointed with the result- I dont know if I should but I expected more power- .The engine made 671rwhp @ 6500 rpm and 583rwtq @ 5400 rpm. That's with 15psi boost,_ YSI with 2.75'' pulley and 7'' crank pulley, 95 octane fuel and 35 deg of total timing air/fuel ratio was 11.8- 12.2 . Charged air temp was 24 deg C.I need to know what I did wrong or is it the engine combo.your suggestion will be appreciated. Thanks.
engine specs,
- Vortech supercharger- YSi-trim.
- Vortech aftercooler.
- 396 ci, 8.0:1 Comp
- AFR 227 heads part# 1076
- Victor JR single plane intake
- LS1 90mm TB
- Cam: hydraulic roller Duration@.050 248/254 lift .562/580 lobe 114.0
- JESEL shaft mount rockers 1.5
- AFR hydra rev
- Hooker Long tube headers
- FAST Classic ecu.
#5
With that low compression....
Drop the timing to around 20* and start adding boost. 8.0 hell put 20psi through it and see what it does.
Numbers don't sound real far off to me. Cam sounds too big to be spinning to only 6500 - or is that just where it stopped making power? Did you log boost? Does it stay steady all the way up top? 20* Less duration and half the timing I bet it would pick up over 100 torque without changing anything else.
The only reason you would need that kind of timing is to get some seriously high octane fuel to burn.
BTW congrats - The first time my boosted motor went to the dyno I only made something like 380 hp.
Drop the timing to around 20* and start adding boost. 8.0 hell put 20psi through it and see what it does.
Numbers don't sound real far off to me. Cam sounds too big to be spinning to only 6500 - or is that just where it stopped making power? Did you log boost? Does it stay steady all the way up top? 20* Less duration and half the timing I bet it would pick up over 100 torque without changing anything else.
The only reason you would need that kind of timing is to get some seriously high octane fuel to burn.
BTW congrats - The first time my boosted motor went to the dyno I only made something like 380 hp.
#6
Its a Dynomite type of dyno.And here is the dyno sheet.
http://www.ls1tech.com/forums/attach...esult-dyno.jpg
http://www.ls1tech.com/forums/attach...esult-dyno.jpg
Last edited by kazdevil; 03-13-2010 at 08:05 PM.
#9
You've got a 396. The big engine (stroke) moves more of your torque to lower RPMs. Take advantage of that torque through gearing. Also, the supercharger has to put out more to get the PSI to the same reading a smaller engine shows. That doesn't mean the power isn't there.
I wouldn't run that engine looking for more power after 6500. Turn it into a mid-range monster and don't worry about high-revving tire melts. You've got a handful already.
I wouldn't run that engine looking for more power after 6500. Turn it into a mid-range monster and don't worry about high-revving tire melts. You've got a handful already.
#10
I think the compression is a touch on the low side for only 15 psi boost. If the engine was built to take the beating that ysi can dish out then pulley down and spin that b!tch up. I agree that cam is also on the large side for the cubes you have. Something in the 230 range would probably make just as much power if not more IMO. More boost, less cam, definitely less timing, ive never heard of small block with that much timing on boost. Anyway you look at it, its still a beast though. What are you trying to do with this vehicle anyways? Dyno #'s aren't everything.
#11
With that low of Compression it needs more COWBELL! ie boost to wake it up
Why so low on the Static Compression? (alot of power/trq loss here)
is this an auto or 6 speed car?
I made 700rwhp and 640 trq @ 15 psi with a six speed car.
If this is an auto non-lock there is alot more to the story
Why so low on the Static Compression? (alot of power/trq loss here)
is this an auto or 6 speed car?
I made 700rwhp and 640 trq @ 15 psi with a six speed car.
If this is an auto non-lock there is alot more to the story
#15
yeah,....i personally think you've got this engine setup to move some air thats for sure. The combination isn't bad persay,......besides the cam being fairly large. A smaller cam, less timing, and spin that ysi up. If you dont want to swap cams, I think your only solution at this point is spin the **** out of the ysi.
Last edited by blown94; 03-16-2010 at 07:34 AM.