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Better Top Speed???

9

97'242

New member
Hi guys,

I am new to this and just purchased my first Checkmate. I got a 97' 242 Convincor that was a single owner and he maintained it to the fullest. It is in fabulous shape and I will post pics soon. I have had it for about 6 weeks now and have had it on the lake for most of those weekends. Needless to say, I have ran it in several different conditions cool, hot, windy, calm, no chop, lots of chop, full gas, and very little gas. The best I can get out of it (this is not GPSed) is 68. The engine is the 454 Mag and it does have Captain call exhaust, other than that I am pretty sure that everything else on the engine is stock. I would love to get to the mid to upper 70's, however, I do not want to pull the engine and rebuild. Is it possible to simply add a supercharger? Or are there too many changes to the motor involved?

If anyone has experience with this and has any suggestions, I would greatly appreciate it?
Thanks again,
Donnie:):banana:
 
The 454 mag is a perfect candidate for a supercharger. I added a B&M/Holley 250 to a 454 Mag in a 265 Baja. I was running 6-7lbs boost. I had a GPS gain of 8-9mph. If you keep your boost in the 3-5lbs range you can operate fairly safe. Higher boosts will wreak havoc on the stock head gaskets. I would recommend a nice exhaust system too(header). I've been told the stock manifolds would probably fine for small boost applications but may be a little limiting. I'm assuming the motor is quite healthy ? Don't think about dropping a SC on a tired motor or you'll be asking for trouble. Get a boost referenced carb to go along with the supercharger. I had Tommy at Chief Engines in Florida work a Holley 950 for me. I know some people were running as big as 1050 Dominators. Try to keep timing about 30* full out. I was actually running a V-6 ignition module so I could run extra intial/base timing.(less lope to your idle) Make sure you have a good fuel delivery system. I upgraded to 1/2" fuel lines. I removed the checkball at the tank. I was able to maintain good fuel pressure with a mechanical fuel pump(5-7 lbs) You may want to check into a cooler t-stat. I ran a crossover(eliminated the water pump) with mine but I don't think it was necessary. I think plugs were AC MR43TS ?! Make sure you have enough room under your hatch ! I had to notch out a small area of fiberglass behind my rear bench seat(was covered by seat backrest) I had plenty of height clearance just not forward clearance.


I'll try to remember if there were any other issues. I know there's a few other guys here that have some supercharger experience hopefully they'll chime in with their ideas too !
 
on gps you are probably around 62 mph and without pulling that motor or adding a blower there is no way to get mid 70 out of it
i have the same boat with a 7.4 and 5lbs boost on a procharger and have seen mid 70 on very chilly days and hardly no gas and only me and wife usually on normal days right at 70 on gps
 
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