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-   -   600 hp 271 how fast? (https://www.offshoreonly.com/forums/formula/60549-600-hp-271-how-fast.html)

merkruzer 10-02-2003 07:40 PM

600 hp 271 how fast?
 
Who has the most hp in a 271?
I just got a 600 hp Volvo, for my '97 271, and Im wondering how fast it will be. Stock with the 415 it averaged 64 with a top of 66. After adding lightning headers, K&N, bumping fuel pressure I saw 66-67 on average with 70.2 as a best ever. Then beefed up to 509 (brodix heads, crane cam, roller rockers remapped ecm etc.)about 500-525 hp (stock efi intake hurtt me) and saw around 70 the first time I ran wot, but a series of mishaps kept me from wringing her out.
I have an article on a non stepped 271 with a 542 Ligenfelder (bad spelling) that went from 63 with stock 415 to 75 and change with the 542, so I figure add the 60 hp, and the couple mph of the stepped hull and I should just come up short of 80mph. Any input on this
Steve:D

cuda 10-02-2003 08:52 PM

I'd say your in the ballpark with that estimate.

C_Spray 10-04-2003 08:29 PM

Does your 600 have Eickert headers, and are you using the DPX drive, or a Bravo?

Chase910 10-04-2003 09:02 PM

I can tell you that a whippled 502 will run 81-83 on fresh water depending on conditions. I believe that whipple claims around 640hp with their kit...so your 600hp should be in the same range.

merkruzer 10-05-2003 05:38 PM

I am using the bravo with this engine, i posted in the Tech section with more detail

merkruzer 10-12-2003 08:55 AM

Ok, next question...... I am looking into a few options for drives etc. C_spray recomends the volvo drive as he has had no problems with the set up in 2 different boats. I like the idea of the duo prop as the boat leans from prop torque, and this will settle most of it down. Not to mention a much better hole shot as this thing was a real dog out of the hole. I am also concidering the ITS to add on, as I feel the extension may also help with the torque, and improve performance overall. Will the x-dim need to be changed? And can I use my std bravo hp with 20 hrs or do I need the xr?
Any one have the ITS on a 271? or another ext box
Thanks

DoTheMath 10-14-2003 09:45 AM

I had a stepped 271 with the Lingenfelter motor in it (541 hp.), boat had full Latham steering and K-Planes and it was a handful above 75mph. Formula put a 1.65 Bravo HP drive on it, not a great idea in my mind - should have been a 1.50, and I was spinning a 32" lab-finished 4-blade, turning 5,800 rpm. Personally I think that is too much hp. for that hull, but that is just my opinion. Boat had a tendancy to chine above 73-74 and was not happy if you pulled out of the throttle too quckly. This didn't however sway me away from Formula all together as I have been considering going to a 292 with the 6.2's, (or whatever model they my come out with to replace the 312 in the near future... anyone hear anything on this yet?).

I think that Formula makes a quality product, just don't ask them to think too far "out of the box" as their success in this area is limited... just my .02:)

Grog 10-14-2003 03:37 PM

Merkruzer -

How do you like the Lightning headers? Would they fit the stock 4" exhaust hoses to the Silent Thunder exhaust system?

merkruzer 10-14-2003 09:34 PM

The lightning headers were great but they will have to be custom fitted to the existing holes. The stock system has the 3 inch risers in them so I ordered the headers 3 inches taller. The headers were about 1-1/2 inch too high, lightning exchanged them (for a small fee) for stock bravo opening, as I opted to delete the mufflers.

merkruzer 10-14-2003 09:36 PM

chase910

how did your buddy's boat run at wot, was it a hand full or was it pretty stable


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