370ci, twin 61s, T56 dyno/track results
10-12-2015, 11:44 AM
#1
370ci, twin 61s, T56 dyno/track results I put my car on the dyno last week mainly just to see where it’s peaking, and took it to an 1/8 mile track to make some shake down runs before tracks close up. Here’s the major details on the setup:
4th gen fbody, 3740lb raceweight
370ci, 10.2:1, stock 317s, BTR 234/239 .612/.610 114+5 cam, BTR dual springs, Pro Flo intake
twin t4 turbonetics 61/65 cast wheel, .68 housings, truck manifolds, 2.25” hot side, 3” downpipes, 2.5” discharge to treadstone 1000hp a2a, 3” charge pipe to TB
E85 (tests closer to 70%), twin walbro 450s in tank, 8an feed 6an return, FIC 160s
faceplated t56, moser 9”, 3.70 gear, 28” tire
stock POS factory ’98 pcm
On the dyno it made 663/661 on 11psi and 17 degrees. See pic below. Curve looks pretty good, peaks around 6000 and slowly tapers off to 7000. Turned it up to 18-19psi, still 17 degrees and it made 876/805. It peaked a little after 6000 but then fell off pretty hard at 6500. I added a degree of timing to it and made another pull, and it made 890/813 before the tires broke loose on the rollers just after 6000. Once it picked back up it fell off even harder. Motor was pretty heat soaked so called it a day. SO…..any thoughts why it’s falling off at higher boost? I don’t think the exh wheels should be choking it yet, maybe housings too small? I had planned to push this to 22psi or so.
I hadn’t made any passes in the car for over 2 years and it was a nitrous car back then, so drove it 65 miles to an 1/8 mile track and got a few shakedown passes in before winter. It went 6.50-6.60s at 115mph with junk 1.57-58 sixties on 19psi / 17 degrees, hitting the rev limiter at the top of 3rd through the traps. Pretty rusty in the seat so I think it should go 6.30s as it sits with some better launches, suspension tuning and not granny shifting it.
4th gen fbody, 3740lb raceweight
370ci, 10.2:1, stock 317s, BTR 234/239 .612/.610 114+5 cam, BTR dual springs, Pro Flo intake
twin t4 turbonetics 61/65 cast wheel, .68 housings, truck manifolds, 2.25” hot side, 3” downpipes, 2.5” discharge to treadstone 1000hp a2a, 3” charge pipe to TB
E85 (tests closer to 70%), twin walbro 450s in tank, 8an feed 6an return, FIC 160s
faceplated t56, moser 9”, 3.70 gear, 28” tire
stock POS factory ’98 pcm
On the dyno it made 663/661 on 11psi and 17 degrees. See pic below. Curve looks pretty good, peaks around 6000 and slowly tapers off to 7000. Turned it up to 18-19psi, still 17 degrees and it made 876/805. It peaked a little after 6000 but then fell off pretty hard at 6500. I added a degree of timing to it and made another pull, and it made 890/813 before the tires broke loose on the rollers just after 6000. Once it picked back up it fell off even harder. Motor was pretty heat soaked so called it a day. SO…..any thoughts why it’s falling off at higher boost? I don’t think the exh wheels should be choking it yet, maybe housings too small? I had planned to push this to 22psi or so.
I hadn’t made any passes in the car for over 2 years and it was a nitrous car back then, so drove it 65 miles to an 1/8 mile track and got a few shakedown passes in before winter. It went 6.50-6.60s at 115mph with junk 1.57-58 sixties on 19psi / 17 degrees, hitting the rev limiter at the top of 3rd through the traps. Pretty rusty in the seat so I think it should go 6.30s as it sits with some better launches, suspension tuning and not granny shifting it.
10-12-2015, 12:10 PM
#2
Take a look at this thread. Louis did some great testing with timing and how it would make great power but the more timing the faster the power falls when it reached its limit. I bet this thing is a beast. https://ls1tech.com/forums/forced-in...on-timing.html