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CMI headers
I Have a set of EMI thunders i just bought like 5 hours on them. I bought these before i realized i was gonna buy new motor and all. So now i have 500hp that i just refreshed and i gonna get heads and some other stuff to get 600hp out of the motor.
So my question is would it be worth it to buy the etop cmi headers or should i just use the emi? |
bump anyone
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The emi's will be ok to 600hp. Not as good as CMI's, but I would use them.
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ok thanks
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I ran the EMI's on 800HP blower motors for 2 seasons till I got my CMI Etops made, noticed no difference in performance of the boat when I swapped them out.
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Thanks Back4More - you just saved me a ton of money!
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Originally Posted by Scarab28
(Post 2756998)
Thanks Back4More - you just saved me a ton of money!
Also, it usually takes either a cam swap or a severe increase in rpm range to get a full 100hp out of just a head swap when you are starting from 500hp to start with. If you were talking about a 500HP merc engine, you are sctually starting with 470hp from the get go. Good luck with your project. |
I ran emi thunders on my 625plus hp big block right up until this fall with short risers and had no problem,i just sold them because i got a smoking deal on some cmis,but i would run them again if needed,the only thing i did was always idled the engine at 1000rpm in and out of gear.
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People talk like the IMCO and EMI manifolds are not that good but I am running IMCO manifolds on my Procharged 502 with mufflers and all of the engine accessories and it is making 850 HP and 845 foot pounds of torque.
http://www.donzi.net/forums/showthread.php?t=55279 |
There is nothing wrong with the manifolds and they will let you make good power, I am only suggesting that you make sure they are compatible with your cam selsection. You may just have to make a few adjustments to ensure none of the big R :party-smiley-004:
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SC'd engines do not need as good of exhaust as N/A engines. The SC will compensate.
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Originally Posted by Griff
(Post 2757102)
SC'd engines do not need as good of exhaust as N/A engines. The SC will compensate.
It's all about the design, but there is nothing wrong with those manifolds. I never said that there was. |
I am talking about a 500hp.
Thanks Guys for the replies i was not trying to say they EMI stuff was junk. I would not of bought it if i thought that. I was just wondering if the 2800 for the cmi's would be worth the cost. As for the HP i was considering buying a 250 blower from the blower shop to put on to get me to 600hp. Would i be better off using the stock heads or changing them? Would i need to run a chiller? Say 250 blower and stock heads what kind of power running 6#'s of boost with the 741 cam? Say 250 blower and brodix or afr heads what kind of power running 6#'s of boost with the 741 cam? If anybody has suggestions,by all means please speak up! What i want is 80 mph in a 25 ft outlaw 1998 |
You should make at least 650hp with the stock heads and the 741 cam and a 250 blower at 6#.
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Originally Posted by ubet28
(Post 2757496)
I am talking about a 500hp.
Thanks Guys for the replies i was not trying to say they EMI stuff was junk. I would not of bought it if i thought that. I was just wondering if the 2800 for the cmi's would be worth the cost. As for the HP i was considering buying a 250 blower from the blower shop to put on to get me to 600hp. Would i be better off using the stock heads or changing them? Would i need to run a chiller? Say 250 blower and stock heads what kind of power running 6#'s of boost with the 741 cam? Say 250 blower and brodix or afr heads what kind of power running 6#'s of boost with the 741 cam? If anybody has suggestions,by all means please speak up! What i want is 80 mph in a 25 ft outlaw 1998 |
Originally Posted by AIR TIME
(Post 2757636)
if you put a 3'' imco box which is in the swap section and you have 500hp with a 28pb1 prop you should hit 80mph. and its 900 bucks
Where is the best price on one and will it help my drive out with the blower. as far as reliability help me or hurt me i would like my B-1 to last this season before i upgrade next winter |
The used imco box is listed in the classifieds. It won't do anything for relaibility or helping the drive survive.
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I am not sure what kind of boat that you have but some boats like a box and some don't. I have a 3 inch rise IMCO box on my boat and a 2 inch short IMCO lower. I have a friend that has the same power and has a stock X with a standard IMCO lower and he is as fast as me! Another thing to think about is what kind of steering do you have. If you already have dual ram hydraulic you will need to add wing plates to the box. If you don't have dual ram hydraulic you will need to get it if you go with a box. Either way you are looking at more than the price of the box. You will also have to pull your engine to install the box and you will have to raise your engine 3 inches to use the IMCO box. These are all things to think about.
I would say for what a set of CMI E Tops are going to cost you could get a procharger M-3 kit and go way faster than anything else you could do for the money and trouble. The EMIs will be fine with a stock procharger kit. |
Originally Posted by 502stang
(Post 2757958)
I am not sure what kind of boat that you have but some boats like a box and some don't. I have a 3 inch rise IMCO box on my boat and a 2 inch short IMCO lower. I have a friend that has the same power and has a stock X with a standard IMCO lower and he is as fast as me! Another thing to think about is what kind of steering do you have. If you already have dual ram hydraulic you will need to add wing plates to the box. If you don't have dual ram hydraulic you will need to get it if you go with a box. Either way you are looking at more than the price of the box. You will also have to pull your engine to install the box and you will have to raise your engine 3 inches to use the IMCO box. These are all things to think about.
I would say for what a set of CMI E Tops are going to cost you could get a pro charger M-3 kit and go way faster than anything else you could do for the money and trouble. The EMIs will be fine with a stock procharger kit. Ok thanks, i have just purchased a hydro add on kit in the summer i could always up grade it to full hydro if that was the case. Also the motor is already out of the boat. The thing with the procharger i just really dont like the way they look. Is the m-3 better than the 250 blower from the blower shop? I am up for what ever is the best way to go. |
Originally Posted by ubet28
(Post 2758082)
The boat is a 1998 25 outlaw.
Ok thanks, i have just purchased a hydro add on kit in the summer i could always up grade it to full hydro if that was the case. Also the motor is already out of the boat. The thing with the procharger i just really dont like the way they look. Is the m-3 better than the 250 blower from the blower shop? I am up for what ever is the best way to go. |
Originally Posted by AIR TIME
(Post 2760881)
there was a stock 525hp 25 ol he put the 3''box and hit 81gps know he went to a merc 600 and 2'' shortie plus 1'' spacer he was working on the speeds of 87 plus. me I have a 2'' shortie 670hp got 83gps but ran out of prop my new motor is a DEAN GELLNER 1000 ABOUT 1050HP OR SO WE WILL FIND OUT SOON:ernaehrung004:.I ran a stock b1 drive from 95 to 06 with out any troubles. new drive will be a b1x shortie. mine boat is a 24ol should break 100 plus.
Change the name to "jet boat killer" |
Originally Posted by ubet28
(Post 2758082)
The boat is a 1998 25 outlaw.
Ok thanks, i have just purchased a hydro add on kit in the summer i could always up grade it to full hydro if that was the case. Also the motor is already out of the boat. The thing with the procharger i just really dont like the way they look. Is the m-3 better than the 250 blower from the blower shop? I am up for what ever is the best way to go. I don't know which one is better. The M-3 will more than likely make more power. The problem with Prochargers is that they don't make much power at lower rpm's unless you spin them really fast. If you do that they make a bunch of boost up at higher rpm's and that can limit what rpm you are willing to go to. I make really good power now with my m-3 but it took turning the blower faster and now I can't go past 5500 without making over 10 psi of boost. A whipple evens out at a point and does not keep on building. The 250 is a whole different story. |
Originally Posted by jeff1000man
(Post 2760884)
100mph in a 24OL. :eek::party-smiley-004:
Change the name to "jet boat killer" My boat has a pad bottom but no steps. |
Originally Posted by AIR TIME
(Post 2760881)
there was a stock 525hp 25 ol he put the 3''box and hit 81gps know he went to a merc 600 and 2'' shortie plus 1'' spacer he was working on the speeds of 87 plus. me I have a 2'' shortie 670hp got 83gps but ran out of prop my new motor is a DEAN GELLNER 1000 ABOUT 1050HP OR SO WE WILL FIND OUT SOON:ernaehrung004:.I ran a stock b1 drive from 95 to 06 with out any troubles. new drive will be a b1x shortie. mine boat is a 24ol should break 100 plus.
Thanks Air Time i have talked with dean and he is getting me some prices together. I have considered going with the 3 inch ext. I just really haven't heard a lot on the performance side of what they do, so if you could elaborate on what the advantage to having one is that would be great. THANKS A 100mph in a 24 that would be flying to say the least. |
Originally Posted by 502stang
(Post 2760903)
ZXXX and Bryon Rose both have Donzi single engine ZXs and are right there at the 100 mph mark. Both have more than enough power to blow through 100 mph. It is just a matter of getting the seat time to get the boat to handle there. They both have step hulls though. I have a 25 zx with an 850 hp 502 and I hope to be right there at 100 mph when I get a day good enough to run the boat!!
My boat has a pad bottom but no steps. |
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