38 top gun porpoising
 

This is my first cigarette..it's a 97 38 top gun, kevlar lipship edition..half cabin..power is 750 hp per side..xr drives..1:35 gear ratio..spinning 29 pitch bravo 1... 4 blade labbed props..looking for some help on how to get rid of the porpoising..

Drop the tabs to 3 or 4 in anything less than 1' chop, and don't trim out past 3 on the drives unless your wide open

A bit of tab at anything less than 55-60 if not choppy water. My boat lays down nice at 65+ but am already near my max of low 70's.

ran it down in florida this weekend and I had to run tabs at 5 to stop porpoising . I would like to try some different props like 5 blade hydros or maximus to see if it will help . tabs down to # 5 slows the boat down to much . any body ever try five blades on non step cigs?

Try a set of stock 4 blades, I don't think 5 blades are the answer. Drives are usually very deep and 5 blades are just going to put more strain on them. I've ran several guns with 3 and 4 blade props and the porpoise was not that much of an issue.

I am surprised you are porpoising. I had 5 blade Maximus props on my 1994 Cigarette Top Gun (full cabin)with notched transom and the old style brovo 1 drives before I converted to Arneson surface drives. I have rollerized/supercharged 600hp engines. I never had to use my tabs, even getting on plane. No porpoise. I had 13% slip at 3200rpm. I did get them labbed and reduced to 15.25 diameter. Before the Maximus props, I had 4 blade hydromotive props and my slip was 25% at 3200rpm. I was always easy with the throttle getting on plane and the drives were always in the water. 8 years and no breakdowns. I recommend getting the Halomax drive showers. The drives got hot and left white deposits on the outside of the drive without the drive shower. The drive shower is a must have. Good Luck..
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Hydros usually do have quite a bit of mid range slip on hulls like this.

Try turning props in.
I had the same problem with a café racer. It helped a little.
Mine was a trs boat.

how did your boat run with the bravo drives and the 5 blade maximus?

I like the 4 blade bravo props as well. The Hyod's don't have enough blade area for that heavy of a boat. Like lil Red said try a set of stock bravo 4 blades and see if that makes a differance. Also do a sanity check on all your inddicators. Make sure level is -0- for both drives and tabs. With the half cabin your TG is about 450lbs lighter in the nose that a full cabin version so she will carry the nose a little higher they are more sensative to trim also.
As said before most TG's have the porpoise issue in flat water until you get to 55-60mph.