mastrdrver

How effective are turtles at regaining lowend with a single plane intake? Also, how exactly are they suppose to do this? I have heard mix opinions on them and was wondering about them before I make a mistake.

Thanks
Jeremy

Lonnie Pavtis

Turtles, for those that are not familiar are aluminum pieces of varying shapes that are inserted onto the intake manifold floor.

They can change flow characteristics by redirecting airflow into the port differently. They have some grooving on them as well to redirect liquid fuel to the cylinders during tmes when atomization is not sufficient. These can be altered to change cylinder to cylinder distribution as well.

Altering plenum volume with these turtles should increase low end torque by improving vacuum signal at the carb & increasing velocity. This must be tested as dynamic airflow is not always 100% predictable.

Without knowing your combination it is hard to know what your low end torque suffers from.

Is it truely due to the single plane intake or is your carb lean due to the reduced vacuum signal it has over a previous dual plane?

Also if talking about a 4bbl type fuel injection manifold, these are likely less effective due to the dry nature of the manifold.

Please post your combination for more information.

mastrdrver

I don't have anything right now, I am just hoping I can have the best of both worlds. The plans revolve around a MP 360 short block, CC 231/237 110 1.6 rrs, Edel Magnum heads, and a BG carb. I am thinking of using a Vic Jr with a turtle instead of a RPM AG.

Lonnie Pavtis

You may actually be surprised. The Victor Jr. does often exhibit decent low end torque. I have used these often on small block Chevys on the street with excellent results. Unless you have a heavy car or very tight converter, it will likely work well for you.

mastrdrver

How well do turtles help distrupute air on a dry EFI manifold? I have seen guys switch from the stock Magnum piece to the M1 and say the lose lowend trq, which is understandable. But, there have been some people that claim that by putting a turtle in, you can gain some of that lowend back. Is this ture? They are using them on M1 single planes with a stock looking 2brl thr body.

HeavyChevySS

so what are the actual real world gains from using a turtle on a single plane intake. Are they large enough to justify buying and installing one.

For example..on my 383, i am using a team G and the engine will be producing between 480 and 520 HP and the effective RPM range is 2800- 6800 rpms. Will it be worth it to install in my engine?

Lonnie Pavtis

Simply put, most manifold manufacturers try to make the intakes as best as possible. Unfortunately for the unlimited engine combinations that exist, only a small percentage of intake choices are available. This means that an intake may be perfect for one engine or be terrible on another. A different cam or carb, could be the difference as to weather you need any intake modifications. The only way to know is to test & retest until you find the best combination. It may work to your benefit of totally be a waste of time & money. Only actual testing will tell. This procedure also applies to carb spacers.... sometimes they help, sometimes they hurt. Wish there was a correct answer, but there isn't.

HeavyChevySS

I see. It makes sense.

How much do these turtles cost for a SBC?