2018 FS showdown posted.

[D.Johns]

Mute point as we all basically make very close to same power in class legal form with the exception of the TVS which is the underdog in the fight. It needs more weight off and/or more blower speed.

Originally Posted by Rob Wright

Off the top of my head that looks reasonable Todd, and it clearly shows that with current legal lift specs the Ford has more combined into/exh airflow potential than the GM and.the Mopar.

Throttle blade area is same/same on GM and Mopar and no surprise since they share the exact same 109mm round bore throttle body.

Ford has an oval-shaped throttle bore & I'd bet it has about 25% more area than the COPO & DP.

In 1997, the high volume production Ford 4v valvetrain was capable of running continuously at 8,000 RPM.....My bet is they got better over the past 20 years.

Not sure how the efficiency maps look for Whipple blowers.....when I asked I was told their data was on a laptop that was in a vehicle that was stolen & never recovered. Unless the 4.0L is horribly inefficient compared to the 2.9L, it has about 38% more capacity....makes sense since 4.0L with 25%-ish slower drive speed matches power output of 2.9L on same/same engine.

Just thoughts........

[Rob Wright]

Completely agree - they're all pretty close & no surprise since all of them are fed by the same compressor.

The OP has been pitching the disadvantages with CJ since the first day that something else ran quicker, so I think it's worth pointing out the advantages of CJ to balance perspective a bit.

Originally Posted by D.Johns

Mute point as we all basically make very close to same power in class legal form with the exception of the TVS which is the underdog in the fight. It needs more weight off and/or more blower speed.

[D.Johns]

Like you stated the 4v has an advantage of valve curtain area. That is an inherent advantage of multiple valve engines. It also has an advantage of valvetrain stability at lower lifts for higher RPM. It also has disadvantages as well even on the valve area as it is a small bore so the valves are shrouded a somewhat. There are inherent pro’s and con’s to every engine architecture and vehicles chassis/aero. The LS and MOPAR as advantages in some aspects and the Modular has some in others. Valve curtain area is not the “smoking gun”. The combinations as a whole are close in the real world(not identical that’s for sure) but any combo could win any round. Everyone will continue to advance their program to eliminate or work around the inherent short comings and capitalize on their strengths.

Everyone will fight to gain an advantage over the competition. The rule makers usually try to keep the parity.(unless corrupt....)

[D.Johns]

Now how about letting us 13/14 guys go to the current available front feed blower(that’s how they come now as IIRC they don’t offer the rear feed any longer)....service replacement.....and the GT350 heads(Boss 302R heads are no longer made).... service replacement.....


Since the rule change for the FSS those request are also almost Mute as you just build a 16/17 engine combo with more compression and more lift for a Showdown motor.

[D.Johns]

I do wonder why they excluded the 2012 Copo Supercharged 327 combo. Other then no one running it once the 350 came out...no one needing to point it out wanting it I guess.

[Rob Wright]

Also agree with this....no single attribute is a smoking gun.

OP and others have been ruminating over the CID differences with no mention of valve & throttle area, rpm capability, and so forth.

Originally Posted by D.Johns

Like you stated the 4v has an advantage of valve curtain area. That is an inherent advantage of multiple valve engines. It also has an advantage of valvetrain stability at lower lifts for higher RPM. It also has disadvantages as well even on the valve area as it is a small bore so the valves are shrouded a somewhat. There are inherent pro’s and con’s to every engine architecture and vehicles chassis/aero. The LS and MOPAR as advantages in some aspects and the Modular has some in others. Valve curtain area is not the “smoking gun”. The combinations as a whole are close in the real world(not identical that’s for sure) but any combo could win any round. Everyone will continue to advance their program to eliminate or work around the inherent short comings and capitalize on their strengths.

Everyone will fight to gain an advantage over the competition. The rule makers usually try to keep the parity.(unless corrupt....)

[D.Johns]

Agreed...it’s normal for this argument to arise as it happens among the car forms all of the time.

1 cam vs 2 cam vs 4 cam. 2v vs 4vs, engine displacement and limitation, size/weight/cost of each package. Stock this vs aftermarket that. Chassis for stock suspension here with brand X for drivetrain for “cheapest” way to go fast.

And the argument will continue. Fun to watch sometimes. Always ends with John Mihovitz 4.6 usually. Lol