Pistons with too much dish?
I saw that but it's still higher than most people would build into a boost engine, I guess It depends on the intended use. You don't want off boost performance to suffer from low compression but you also don't want compression to limit the amount of boost you're able to run and give up performance on boost either.
I always try to base my engines around 195-200psi cranking compression. The reason your new motor was less responsive was because you Needed to have your IVC dialed back a bit so it could be tailored to your new static compression, slightly earlier IVC, so more cylinder pressure could be retained. The dished pistons allowed the cylinder pressure to drop. Whenever I have my cams spec’d I usually tell the guy spec’ing it that my compression is 1.5-2 points lower than it really is, then I use a compression calculator and play around with cylinder head Volume CC to tailor my dynamic compression ratio/cranking compression, this method has been very successful for me. As the camshaft gets larger (as duration increases) static compression also needs to be increased in the same fashion, to gain back some of the lowend torque.
I always try to base my engines around 195-200psi cranking compression. The reason your new motor was less responsive was because you Needed to have your IVC dialed back a bit so it could be tailored to your new static compression, slightly earlier IVC, so more cylinder pressure could be retained. The dished pistons allowed the cylinder pressure to drop. Whenever I have my cams spec’d I usually tell the guy spec’ing it that my compression is 1.5-2 points lower than it really is, then I use a compression calculator and play around with cylinder head Volume CC to tailor my dynamic compression ratio/cranking compression, this method has been very successful for me. As the camshaft gets larger (as duration increases) static compression also needs to be increased in the same fashion, to gain back some of the lowend torque.
ETA...I really only wanted to share my results because it was apples to apples where literally the only thing changed was static compression ratio. Was it ideal? Absolutely not. Low end torque is where I felt the biggest loss though.
I want to put things into perspective a little more before you all laugh too much...
11 years ago with that car on nitrous it ran 10.2 consistently with a 2 hour drive each way to and from the track. There was a street car competition with around 200 cars showing up. They took the fastest 8 around 2 am to run off. I made the semis before losing to a fox body. Today that 10.2 car would be the slowest car at the track. I don’t know if any other decade where street racing changed so much in ten years.
11 years ago with that car on nitrous it ran 10.2 consistently with a 2 hour drive each way to and from the track. There was a street car competition with around 200 cars showing up. They took the fastest 8 around 2 am to run off. I made the semis before losing to a fox body. Today that 10.2 car would be the slowest car at the track. I don’t know if any other decade where street racing changed so much in ten years.
A 10.2 car that actually gets driven 2 hours or more at a hop is still a damn fast car. The average Joe that takes a ride in a legit 12.50 car thinks it’s really a bad bitch...because in reality it ain’t a joke. That’s more than 2 seconds quicker than his dads bad *** 396 chevelle especially on street tires.
People have no idea how much work it was to run mid to high 12s in a pump gas street tired car even in the 90s. GN with some work and 5.0s with flowmasters and a 150 shot being the normal ones. There was also the guys that had the Tuned Port and LT1s doing alright but the broke *** guys only had the Mustangs.
First time i me I saw a holy **** street car was when Mike Murillo drove to Alamo Dragway and his buddy followed him with slicks and a floor jack in his S10. They parked right in front of me and ripped some mid 10s after driving it from the north side. I was running a trailered 11.30 to 11.50 ET TRW pistoned 383 in my Valiant at that time while I built my bad *** 451.
Its a diminishing return thing for your adrenaline fix is the real problem. I had just as much fun then as now and honestly more even if now I can build the cars I coveted so much at the time.
Enjoyment is what counts. The fastest and quickest will always be in the other lane eventually anyway until he gets whacked the next round.
That said..... FOCKKkkk losing. It still sucks I just get over it sooner compared to then.
People have no idea how much work it was to run mid to high 12s in a pump gas street tired car even in the 90s. GN with some work and 5.0s with flowmasters and a 150 shot being the normal ones. There was also the guys that had the Tuned Port and LT1s doing alright but the broke *** guys only had the Mustangs.
First time i me I saw a holy **** street car was when Mike Murillo drove to Alamo Dragway and his buddy followed him with slicks and a floor jack in his S10. They parked right in front of me and ripped some mid 10s after driving it from the north side. I was running a trailered 11.30 to 11.50 ET TRW pistoned 383 in my Valiant at that time while I built my bad *** 451.
Its a diminishing return thing for your adrenaline fix is the real problem. I had just as much fun then as now and honestly more even if now I can build the cars I coveted so much at the time.
Enjoyment is what counts. The fastest and quickest will always be in the other lane eventually anyway until he gets whacked the next round.
That said..... FOCKKkkk losing. It still sucks I just get over it sooner compared to then.
