The Poston 112 and TA 310 cams are actually really similar in HP and TQ curves so this dyno info should be applicable to the spacer effects: The Poston 112: And the 310:
May only have 2 to 5 more on the power but you take off 30+ lbs off the front end and that alone will make the car run faster. Also the engine cools off faster, which will make the car faster since it can cool off at a greater rate. Everyone fails to forget that with the TA intake you can use the carb you like and not be limited to the Q-Jet as this is THE only carb that can be used on the stock intake.
This would typically be true for single planes, but the SP3 seems to be a different beast. Up to now, the only single planes available were custom builds which followed the traditional single plane design, and so this statement holds true in a general sense, particularly in the past and with different engine types. The Buick 350's tall and narrow runners add an interesting twist to the story, though. The SP3 seems to follow this same pattern, keeping velocity up while simultaneously increasing flow potential. You can thank the tall narrow runners for this, which all other single planes do not have, or at least not to this degree. The weak link in the single plane's design (for street use) is the open plenum which is inherent to all single planes of course. I suspect (not proven yet, at least not with this intake that I know of) that adding a 4 hole spacer or decreasing the CFM of the carb would aid in retaining some velocity before the fuel charge reaches the runners, and thus making this intake doable for street applications where the power peaks between 4500-6000 RPM. For more radical applications, porting the intake runners will help the intake behave more like the traditional single planes we're used to seeing. Remember the Buick 350 flows air differently than a Chevy. Traditional parts that we're familiar with which are used on everything else won't look or behave the same for the Buick 350, and this applies to previously made aftermarket parts for it, before this knowledge became readily available to those who were not part of the engineering team back in the 60's. The SP3's design is no accident. TA put a lot of thought into this to make this intake as versatile as possible to maximize sales. Gary
I agree Gary I think it is too early to write off the single plane. More testing will show the results.
I've used the TA dual plane on an otherwise stock 1970 SP engine with zero gained at the track. The weight savings is nice. But the aluminum intake will also wick heat into your carb and I've seen Holleys boil the bowls empty on a hot shutdown. I believe the SP3 would work well with the Crower level 4 cam. Level 3 cam seems to be the limit of iron manifolds.
I've been running my SP3 for about a month now - swapped it in for my TA dual plane with no other changes as to carburetion, timing, transmission, etc. SP3 has increased power across the board for me, though I don't have hard data to offer in further support thereof. I know for a fact in my case at least the motor picked up acceleration strength measurably from idle all the way up to approx 90 mph (the highest I've pushed it to date). It especially shines in the higher rpm range (3500 and above) on my motor - my car never pulled as hard in general before with the DP and it definitely feels less winded at speeds above 75. Only other real mods to my motor ('70 SP) are HEI, a Comp 260H cam and a well tuned mid-70's electric choke Qjet. I'm also running 3.23 Posi gearing and 2.25" dual exhaust (Magnaflow mufflers). I think it's a great alternative to the DP, especially for anyone contemplating the aluminum heads whenever released.
The trade off on HP vs torque loss on the poston cam seems kinda large and the the 310 cam torque is kinda disappointing. Should be able to make 350 HP with 425 lbs with this engine. Even am&p 350 dyno 335/375.can't wait to get my car back from interior and paint and pull the 310 for my level 3. I'm going to try the sp3 on it also hope it don't kill much low end
Notice the dyno program is displayed as the 'seat to seat' setting. Don't let those numbers mislead you. The HP will be higher, and the torque lower, at the 'seat to seat' setting. You take the '@.050' setting and HP will be lower and torque higher. What I do is average these out by adding both peaks together and dividing by two to get a more accurate reading. In other words, take torque @seat to seat and the .050, add together and divide by 2 to get the average. Do the same with the HP readings. You can do the peak @RPMs this way too, to get the average peak RPMs for each. There are other tricks I use, but this information is enough for now. Gary
Might it be possible that a slightly more restricted intake (or runner or 2) clips the peak hp a bit but hangs on going over the nose, leading one to see a higher peak rpm, but at lower hp?
Here is what my intake did with the 510 cam on the dyno, think the stock intake can take it this far?
I read all the reviews and results before I bought my TA dual plane intake. For me it is well worth the money for the weight savings, not as far as increasing ET’s, but mainly for my 50 year old back. After removing and reinstalling the factory cast intake in the car once I placed my order! Love that aluminum intake.
The Sp3 needs to be tested to see where the power comes on as compared to the TA or stock intake. And I agree the aluminum one is 10 times easier to put on as compared to the stock intake. If you could do something to the stock intake to make it gain 10-20 hp over the TA D/P then maybe you have something. I would think you could get more with the TA D/P than the stock intake as far a putting spacers on and different carbs and such. Then there's the SP3 need dyno against the other 2. and is it really slower out of the hole as compared to the stock or the TA D/P. bet not much
I weighed and compared a 4bbl 340 iron intake against an aluminum 300 2bb and it came out 30lbe heavier which was more than I expected. 43lbs vs 13lbs. Jim
