MPH Testing

[whitelightning]

Had the day off today and it was 83 degrees at Tablerock Lake. I decided to do some top speed testing with White Lightning. (1998 252 w/502 MPI mag) I'm pretty happy seeing 62.07 MPH @ 5000 RPM in 1 foot rollers with a GPS app. It ran 49MPH @ 4000 RPM. The RPM limiter is set to 5400 so it's got more RPM left. That was with only me on board, gear, 1/2 tank of gas, 6 batteries(stereo can run for days, LOL) and less than favorable density altitude.(912 feet elevation, 83 degrees, 54% humidity, 28.6 pressure = 4450 feet density altitude or feet above sea level) All testing was with a Bravo 1, 4 blade 22p. I think it could absolutely go 64-65 in optimal lower density altitude conditions and no gear or extra stereo batteries on board. This fall I can easily get the boat on the water and into some lower humidity, high pressure air where the DA will be below 2000 feet. The cooler water in the lake won't hurt either.

[Big Block Power]

Get a 23 at least mirage plus prop for test day. Spin that baby up.

[whitelightning]

Ok, I'll start looking for one. No matter what the MP won't be replacing the Bravo 1. If for any reason, just for a top speed test but the Bravo is slam dunk, hands down a WAAAAYYYY better prop on these boats, just not quite as fast. Nothing gets out of the hole like this Bravo.

[Big Block Power]

Have you ever tried a rev 4. It's a beast out of the hole and midrange. If you can find one to try I would suggest it.

[whitelightning]

Certainly is worth trying. Keep the tips coming.

[whitelightning]

Hey, thoughts on a Whipple super charger? LOL

[Big Block Power]

I know a guy that added one for 10k and gained 1 mph. Lol

[thunder550]

Good results. Runs stronger than mine does.

[akorcovelos]

There is a guy on Facebook that has a Whipple charged 7.4 Mag in a '96 252, claims 74moh gps. Run the numbers and that roughly $1200/1 mph versus a good tune and prop selection on stock Mags. These aren't go fast hulls, at a point the return on investment stops making sense. The same stock 7.4 and 8.2 Mags in true go fast hulls will run 70s all day long.

Nice numbers lightning, aren't you the one running the Arizona Speed tune?

[whitelightning]

Good results. Runs stronger than mine does.

Thanks!

[whitelightning]

There is a guy on Facebook that has a Whipple charged 7.4 Mag in a '96 252, claims 74moh gps. Run the numbers and that roughly $1200/1 mph versus a good tune and prop selection on stock Mags. These aren't go fast hulls, at a point the return on investment stops making sense. The same stock 7.4 and 8.2 Mags in true go fast hulls will run 70s all day long.

Nice numbers lightning, aren't you the one running the Arizona Speed tune?

Yes, it's got the ASM kit on it (+25 HP). Yeah, I hear what you're saying. Absolutely, if the engine was in a Checkmate Convincor, it would absolutely run 70 but then again, that's not a Cobalt.

[thunder550]

What did that ASM tune run you? Did they offer any insight as to effect on engine reliability or expected life?

[akorcovelos]

Yes, it's got the ASM kit on it (+25 HP). Yeah, I hear what you're saying. Absolutely, if the engine was in a Checkmate Convincor, it would absolutely run 70 but then again, that's not a Cobalt.

I saw you said before that it was a kit, but I could only find a link to the tune on their site. Did you buy the hard parts (MSD and High flow spark arrestor) from them with the tune?

[akorcovelos]

What did that ASM tune run you? Did they offer any insight as to effect on engine reliability or expected life?

Just the tune on their site is $395 if you send them the ECU. Nobody stocks MEFI 1 or 2 anymore, so if you want to keep your stock ECU stock you need to find a good used ECU to send them, like I plan on doing.

https://azspeed.com/product/ecu-calibra ... t-engines/

Correction, AS&M shows stock on MEFI 2, but at $895 just for the ECU without tune. I've been finding MEFI 2 units for under $300 so probably better to source it yourself.

Same thing with Whipple:

https://whipplesuperchargers.com/index. ... uct_id=410

[whitelightning]

Here is the kit, but it has been discontinued. It was already installed on the boat when I bought it.

https://azspeed.com/product/454502-mag- ... -tune-kit/