|Brucato SVS intake and a performance exhaust tuner change were all that was needed to gain nearly 30 hp on the 225 Pro Max and add 8 mph to our Bullet 20XD.|
Chris installed a 12-inch setback Cook Manufacturing Power-Lift
hydraulic jackplate on the transom so we could make height adjustments
faster and easier on the water, and slipped on a 31-inch-pitch Spinelli
as the new base prop as dictated from our earlier tests. Then it was
off to the Back Bay again.
The first run was with the jackplate lowered so the propshaft was even
with the bottom of the pad. Subsequent runs were done raising the
Power-Lift 1/4 inch at a time, recording the Bullet's perfomance with
each minor change in height.
This setup was getting closer. After a dozen such passes, the sweet spot seemed to be with the propshaft 1 1/4 inches above the pad. At that point, holeshot dropped from the base of 5.86 seconds to5.3s while top-end brought consistent 88s.
Raising the engine higher brought the speed down as did setting it lower in the water. The engine was still turning 6700.
(We disconnected the SVS system again at that point, just for fun, and lost 4 mph.)
Still not satisfied, but seemingly on the right track, Chris slipped on
a 32 Spinelli and did the runs again. This time the sweet spot came a
1/4 inch higher, and it was there that the gun read 91 and change, with a 92 coming on one pass after fuel was getting low. Holeshot remained in the mid-fives, with a mid-range acceleration and throttle response that Chris says feels like "adding a shot of nitrous."
Water pressure remained a solid 20-plus psi during the final runs,
indicating good flow and engine cooling from the Sport Master lower unit. The biggest drawback to the big four-blade chopper and high
propshaft location is steering torque. "I would highly recommend hydraulic steering to anyone who is planning on using this
combination as a standard setup," warned Chris, massaging aching arms after the last test session. "The steering torque at these
(high) speeds and engine heights is awful with the Spinelli. Your arms start aching after a couple of runs."
What does all this mean to the average performance-oriented bass fisherman? It means answering some serious questions, like the
Is spending $2500 (the cost of parts and labor) to get those extra ponies worth the potential gain in speed and throttle response? Is
running a "chopper," with its thinner blades and poorer weight-carrying ability, compatible with your style of fishing? How does the added horsepower relate to the hull's maximum horsepower rating? Finally, is the price of speed worth possibly voiding the engine's warranty?
These are all tough questions. The answer for the typical bass angler is most likely going to be "No, I'11 be content with my 225, as is."
However, for those who are getting used to driving their 2.5L 225s and want to feel a new adrenaline rush, having these relatively easy
modifications done to their engine's powerhead may be worth the price.
There's no doubt the Brucato SVS and exhaust tuner change wakes up a 225 Pro Max, as it should the other 2.5 blocks as well as the 3.0-liter Big Block. Throttle response from about mid-throttle to WOT is extremely strong and the majority of bassboats will probably respond quite well to the modifications.
|FINAL TEST NOTES: BULLET 20XD W/ MODIFIED 225 PRO MAX|
|PROP||PROPSHAFT HT.||AVG. SPEED||RPM|
|Trophy 26||1" w/o Brucato||82.5||6750|
|OMC SRX 29||1 3/4" w/ Brucato||86.2||6750|
|Spinelli 30||1 1/2" w/o Brucato||84.0||6750|
|Spinelli 31||1 1/4" w/o Brucato||84.3||6200|
|Spinelli 31||1 1/4" w/ Brucato||88.2||6600|
|Spinelli 32||1 1/2" w/ Brucato||91.5||6600|
|Tempest 27||1 1/4" w/o Brucato||85.0||6600|
|Tempest 27||1 1/4" w/ Brucato||86.0||6750|
|Yamaha Pro S 27||1" w/o Brucato||83.1||6600|
|Yamaha Pro S 27||3/4" w/ Brucato||83.6||6700|
| ||1 1/4" w/o Brucato||81.0||6750|
|Engine water pressure stayed consistent throughout tests at 20 psi.|
|Stock Sportmaster lower unit with 1.86:1 gears.|
|Spinelli props had the worst steering torque, but best hook-up.|
|Using Cook Manufacturing Corporation 12-inch Power-Lift jackplate.|
|The final test session included seven props, run at 1/4-inch height intervals until the best speed was achieved with each. These are the best figures for the props tested, where average propshaft height was 1.25 inches above the pad.|
Dialing in the prop and engine heights should be easier on the heavier hulls, too, while lighter, faster combinations will proba-
bly run into the same dilemma that we faced with making our Bullet faster--you run out of prop before you run out of power.
Overall, we were pleased with the end results. Gaining some eight miles per hour is a significant improvement in any boater's handbook, let alone doing so at speeds already starting in the low 80s. Having 250 hp on the transom definitely makes for a "Faster bullet."
Now that we have one package under our R&D belts, we are going turn our attentions to a '97 Mere 150 EFI on a Gambler Outlaw to
see how it responds to the same modifications. Can we achieve a higher percentage in horsepower gains with the little stocker
than we did its big brother Pro Max? Time will tell. B&WB
|SPECIAL THANKS TO:|
Crown Leisure Marine (800/972-2277)
Brucato Machine & Tool, Inc. (561/744-5629)
Bob's Machine Shop (800/966-3493)
G-Force Technology (920/235-5442)
Cook Manufacturing (800/654-3697)
Bullet Boats (423/577-7055)
Land & Sea (603/329-5645)