heatwave3

No drinking...not even a cold one when I'm operating until I'm back to shore. Just the way I've boated safely for coming up on 2 decades at pretty high speeds with lot's of paessengers in both the Ocean and large freshwater lakes.

If you're comfortable operating a slower speeds, there's no downside. Just like I wouldn't suggest a driver operating a car at 15 mph isn't necessarily irresponsible, I'd never suggest the operator of a boat is irresponsible at ANY speed, so long as he/she sticks to the original comments I made.

Know your waters, know your weather, know your boat's capabilities, know your capabilities, know your passengers and what they like and IMO there's no speed too fast or for that matter too slow. If you don't know these capabilities or exceed any of the above, you're probably going too fast

Speed has nothing to do with being responsible so long as the other factors are taken into consideration. A few thoughts you might want to consider.

wwwTOPDJcom

I was running with one of those by my side this weekend and he seemed to keep up very well must of been doing 64 ish with 3 or 4 guys aboard

man I feel good my 502 in this Senza Spectre 26 is getting me a best of 70.6 gps with 1/2 tank+, 2 adults ,cooler of drinks and a bit of gear,
if I take the gear and the wife off and run 1/4 tank it goes up to 71.8
which is a BIG improvement over the Alpha/350mag from last year which was 52-53 max


Im starting to think this motor I picked up is more like a HP500 EFI

articfriends

Heatwave,i just returned from vacation (boating,of course) and i see you posted your gps speed vs speedo speed. My respect for you just increased immensely, i seriously had questioned your boats ability to reach the speeds you were posting before, knowing you only had a 502 w a m-1.As far as going 70 in your boat with passengers,i probably wouldn't do it with 8 people on board but i quite often get into short 2-3 mile races with 4 agreeing adults in my boat at speeds as high as 82-83 mph but we are all experienced adults and besides,nothings more fun than having your passengers wave goodbye to some cocky guy in a boat thats more exspensive and typically faster than mine that already waved goodbye to us at 65-70 thinking he wasn't going to have a baja walk away from him like he was going backwards!!!!Smitty

heatwave3

Smitty,

Hope you had a nice vacation. I think the boat (M1SC 502mpi, Baja 272 Islander) could reach 72-74 GPS with only 2 of us on-board instead of the 8 I had at 71GPS. (Unfortunately for testing purposes thats tough as whenever I go out there tends be a gang that wants to go as well).

In fact I'm going to test out a 28"Bravo this weekend to see if it might be a candidate for being "worked". Last time I ran it the engine turned 4750-4800 and 77 on the speedo (I didn't have the GPS yet). My guess is that it was about the same speed as the 26" at 5000 rpms (71gps). I'm hoping to get more info (hole-shot, mid-range, cruising speed/rpms and top end) with the GPS this weekend.

If I'm able to get 71GPS out of the 28" Bravo at 4700 would it be a better candidate to be worked or would the 26" Bravo at 5000 doing 71GPS be the better prop to work on. MY ECU was done by Arizona and I believe the rev limiter is set at 5250. I would prefer not banging up against the limiter however the I suppose the engine is going to be performing better at 5200 even with the stock cam given the greater boost that would be generated from the M1 (currently at or slightly above 5psi).

Interested in your thoughts on the better prop direction.

articfriends

Heatwave,if your boat only pulls 5000 w/26 pitch,i would get prop worked a tiny bit or raise the boost. My boat liked the 26 pitch when i ran 5 psi on the 502,maybe get the rev limiter bumped up to 5400. It sounds like the majority of the time your boat is heavily loaded. If you haven't converted your boat to roller rockers and better pushrods you need to do it ASAP!! I had cheap roller tip comp's that still used the stock style fulcrum with oil grooves and they were BLACK and one fulcrum ball was missing a piece after the first full season of running hard on my 502!! As far as the rev limiter,you'd be even better off to have it raised to 6000 so it never kicks in and leans your fuel out then use a msd 6al box with whatever chip you feel comfortable with,thats how i had mine setup.The stock cam is small but still will have no problem pulling to 5400 if your running 7-8 psi boost. The 28 pitch w/m-1 will be loaded down pretty hard and won't accelerate like your 26 even if you do get it to go same speed,Smitty

heatwave3

Already been there and done that on the top end of the engine (learned many lessons 15 years ago with a previously owned blown 454 - B&M 174).

On this engine I had the head gaskets upgraded, Harlan Sharpe rollers installed, hardened pushrods and iconel severe duty exhaust valves before I added the blower (bottom-end is all stock). I'm considering raising the boost since on the laptop it shows absolutely 0 knock retard. Fuel pressures running at 58psi (50psi on the dash gauge) on a gauge I run from a shraeder valve I have installed between the fuel filter and fuel rail. (BTW, I've added a spilt in the fuel line after the filter that dumps the fuel at the front and main inlet of the fuel rail per the latest instructions from ProCharger.

I've kept the stock cam due to the Silent Choice which I didn't want to give up. More overlap with a more agressive cam combined with the short risers needed with the Choice setup and you're asking for water reversion problems (been there done that years ago as well).

I'm alittle hestitant to bump the boost as I'm running stock injectors. Did you upgrade the injectors when you increased the boost? I thought the stock cam is past its peak at 5000 rpms therefore is there really much benefit above 5000 other than spinning the blower faster? Were you running the stock cam with your 7 psi setup and what were your rpms?

articfriends

heatwave,i'm STILL running stock injectors on 540,i had them flowed and had high flow screens in them at crocketts,they supposedly flow 47 or 42 lbs per hour. I ran 32 psi base press on 502(with crocketts program) and 55-60 w/o. I run 48 base w/540 and about 75 psi under boost now. I am at about 115 hours on 540 and it still hasn't melted down. What year and size are your injectors? I ran 502 up to 5400 w/stock cam,you have to remember that it was supposed to peak at 5200 stock and if you boost it 1/2 atmospeheric pressure (7.25 psi) that you have FORCED the engine to 120-130% volumetric effieciency (compared to 80% n/a). So even though your cam only has 485 lift,its getting air pushed through real well while its open. It will continue to make more power somewhat as it rpm's higher and your boost increases (I'm no expert at this by anymeans) but if your boat goes 71 mph at 5000,it will go 75or so at 5400 simply because rpm's equal increased prop speed which equates to more actual speed (unless your power was dropping off instead of increasing).I saw about 75-76 with stock cam in 502,8-9 psi boost,26 pitch at 5400(if memory serves me correctly),i saw 78-80 w/stock cam around 5200 at 8-9 psi boost w/28 pitch (i had went from 4.25 pulley to 4.00 pulley at the time). The motor WASN"T completly stock then though,it also had merlin 310 heads and lightning headers and don't forget i am running m-3 and aw504 not m-1 and smaller intercooler,Smitty

heatwave3

Question: are the injectors from a recent model 454 the same as the injectors on a recent model 502. The reason I ask is that the 502 I'm running was built using a 502 short block and an accessory swap from a broken 454 that was in the same boat.


Did you have any work done to your 26 or 28 Bravos? If so who did the work and what did you have done?

I'm surprised you were able to generate so much boost, even with the M3, on a 4" pulley. I recently swapped my 4.25" pulley for the 4" pulley and it only added at most about 1#. Did you have your prop worked at the same time as you changed the pulley and could that have contributed to the higher boost/rpm performance?

articfriends

I don't know the answer to your injector question other than crockett calls them "Mini's".As far as boost,you have to remember a m-3 is 50% bigger than a m-1 and that(i'm guessing here) the pressure drop acrossed a aw504 compared to a 324 is 2 psi less.Also,the internal step up gearing on a m-3 is different. Also my 502 would make 8 psi boost with the 4" pulley and the same setup on 540 was around 6-6 1/2(feeding more cubic inches). You can't really compare boost between the 2 different blowers and intercoolers. I bet your intake air temp is higher going into your motor,if it was my set-up i would try to find a used aw504 off e-bay and add it to your boat over the winter. If Tomcats intercoolers truely outperform the aw504 hands down there should be a few more aw504's for sale on the market too,you could even provide him with contact info for the next time he upgrades one for someone to setup a sale to offset there investment with him.If you lok at the post that 502 procharger did under my "articfriends" you'll also see a couple of guys that say they are getting 8-10 psi on 540's with the m-3 and a carb w/4" pulley(i think there air drop going into carb box isn't as high as the drop acrosed the inlet to a efi plenum),Smitty

heatwave3

Had a chance to test out my 28 Bravo 1 this weekend. Water was rather nasty in the Barnegat Bay and I was only able to find a few short stretches of calm water to do some testing.

I had 6 people on-board and a full tank of fuel (90 Gals) running in some tough chop so my results should be worst case.

With the 28 Bravo I just broke 70mph gps (78 on my speedo). I was turning 4800rpms with 5psi of boost. Engine stayed nice and cool at 150 degrees with 50 psi fuel pressure and plenty of oil pressure. 3500rpms ran 50mph, 4000 ran 60mph and 4800 ran 70 (all gps speeds).

Last time I ran the 26 Bravo (half tank of fuel and 8 people), I ran 71mph at 5000 rpms and just short of 6psi boost.

One strange thing was the fact that my Hi-speed Nordskog kick-up knife speedo read 75mph with the 26 Bravo when I topped out at 71gps. With the 28 Bravo the speedo read 78 when I topped out at 70gps. Probably just a coincidence however the speedo readings were very stable. Is there ever any variation in gps? Boat definitely felt faster with the 28 Bravo than the 26 and showed 3 more mph on the speedo but I guess the gps doesn't lie (or does it?). Anyone else have this type of discrepancy?

Now the question is which is the better prop to get worked? If I lab finish the 26" I probably bump up against the 5250 rev limiter. Is it possible to gain 300-400 rpms from finishing the 28"? If so, that would get me around 5100-5200rpms and probably the best top speed I can expect from the current engine setup. Thoughts?