1989 242ss prop/exhaust

[seef158]

Hey all,
Just thought I would let you know how my prop change worked on my boat. 89 242ss with 330hp/bravo 1 outdrive. I put emi thunder exhaust on this winter and changed to a 22pitch bravo1 4 blade prop. Before the exhaust i was running about 49mph right at 4600 rpm with a 21pitch mirage. After the exhaust manifold change i was at 50mph at about 4750 rpm. I put the 4 blade bravo 1 prop on and now i am seeing 56mph at 4200 rpm and much better on gas and the boat rides much better, the prop lifts the whole boat up, i would recommend this prop to anyone with an older single engine formula.

[Monaco20]

Originally Posted by seef158

Hey all,
Just thought I would let you know how my prop change worked on my boat. 89 242ss with 330hp/bravo 1 outdrive. I put emi thunder exhaust on this winter and changed to a 22pitch bravo1 4 blade prop. Before the exhaust i was running about 49mph right at 4600 rpm with a 21pitch mirage. After the exhaust manifold change i was at 50mph at about 4750 rpm. I put the 4 blade bravo 1 prop on and now i am seeing 56mph at 4200 rpm and much better on gas and the boat rides much better, the prop lifts the whole boat up, i would recommend this prop to anyone with an older single engine formula.

Hi
Very interresting reading! A hugh change in top speed *S*

How is the midrange, and is slow to plane?

The 454 330 hp should hva aprox 4400 to 4600 rpm on full
throtle

I have a 1988 242 SS with 454 330 hp and 17 mirage pluss
and need to change the prop.

I was thinking to buy a 19 mirage, but after your results I consider change and try a 4 blade brovo 1 prop.

What kind of pich does it have??

best regards

from Oslo, Norway

[tpenfield]

so how much of the performance boost was from the emi thunder and how much was from the prop.?

[masi242]

On my 242LS I run a Bravo1 four blade 22p labbed a run it to about 4500-4600 RPM. The best is 54.7 gps.

[seef158]

the bravo is a 22pitch prop. The new manifolds gained me about 12-1500 rpm with the old prop-mirage 21pitch. my speeds are on the stock speedo which I have compared to gps and it is optimistic by about 1-2 mph, meaning i had 49.5 on gps when the speedo had read about 50-51

[mopower]

A friend of mine had a 242 with a 502 mag. He went from a 23 Mirage to a 24 Bravo and picked up an honest 5 mph at 3000 rpms. About 1 mph gain top end because he could trim higher without the prop losing its bite.
Next step was a warmed over HP500 at 535 hp and picked up 8 more mpg top end for a total of 69.9 GPS

[Monaco20]

Originally Posted by mopower

A friend of mine had a 242 with a 502 mag. He went from a 23 Mirage to a 24 Bravo and picked up an honest 5 mph at 3000 rpms. About 1 mph gain top end because he could trim higher without the prop losing its bite.
Next step was a warmed over HP500 at 535 hp and picked up 8 more mpg top end for a total of 69.9 GPS

Hi Mopower

I have a 242 SS 1988 with a standard 454 330 HP 1997
GenV. The prop is a Mirage Pluss 17, I know the prop
is to "small"
Ex.:
3200 rpm my speed is 28 miles
My rpm is much higer then it is supposed to be, but I have
never taken it higer then 4500 then I get aprox 43 miles.

I have a lot more throttle to give but, I havent let the engine
gone over the 4500 rpm.

I am going to buy a new propp, but I am not sure what kind of
prop either mirage or bravo1?

My normal boating is 2-4 people some gear, I am not to stressed by top speed, but of course everybody want his boat
to go as fast as possible.

I would like it not to be to slow to plane, and have a good midrange preformance.

So what should I go for??