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View Full Version : The cats out of the bag



Lil Grizz
09-01-2002, 03:46 PM
From the Lake Lanier Skunk Works:
Well its out, I supercharged my 22zx. I was trying to keep it quiet for Eufala but word spread pretty quickly. I was asked two questions upon my arrivial; "You guys sure got up early didnt you?" and "Hows that Whipple?" Well yes I did get up really early about 4a.m. and the Whipple is just fine:).

Heres the scoop. The engine is a 1999 7.4 MPI rated at 310 php. No mods at all before the install save for rex marine exaust tips and a little trimming of the throttle body gasket. On its best day I could run 62GPS @ 4600Rpm turning a 24p bravo 1. The 310 7.4 is supposoedly limited to 4600 so I intend to never exceed that. Right before I started wrenching I baselined the boat at 59.4GPS. With less than half tank and a zillion tries that was the best speed for the day. The water was glass and it was at least 94 degrees and im sure that worked to my disadvantage.

The install was easier than you would think. All I had to do was take off the intake manifold, put on the charger, plumb a line into the sea pump, modify my fuel pressure regulator, and reroute the throttle cable. The only glitch was an ECU programming mishap that delayed starting the engine for a few weeks. The ECU is still not dialed in and its running really rich under 3000rpm and somewhat rich above. Better rich than lean so until the season is over I wont mess with it. It took me about 8 hours of work to install and that is including the head swap. Yea I swapped the heads, but not for a better performing set. The L-29 fast burn heads that come on the 7.4 sometimes detonate when under boost due to their chamber design. Didn't want to find out if I would actually have that problem. I swapped on a set from a gen V 7.4 for 2 reasons, 1)They are near identical in airflow and compression(even though their intake ports are smaller) and 2) they were FREE(and had a complete valvetrain overhaul at that)!

Now for the performance:
First day out with a 28p hydromotive 4-blade went 74.3@4500 GPS. When the ECU was reprogrammed the rev-limiter was removed for some reason so I held back to save the engine, it still had more to go before it was WOT. I spent a few weeks prop testing and settled on a box stock 30p bravo 1. With that prop I get about 77.x@4500 gps. I can hit that speed every time we test, very consistant 18mph gain.

This weekend at Eufala the boat must have been showing off for "The Big Three" since it was holding steady at 79mph, AMAZING! I danced a jig on the backseat. Would have loved to see an honest 80 but just didnt happen, maybe when its tuned better. It is a very good looking kit, Heres my engine. http://www.donzi.net/photos/MyBoatEngine.jpg http://www.donzi.net/photos/MyBoatEngine2.jpg http://www.donzi.net/photos/MyBoatEngine3.jpg

Moody Blu'
09-01-2002, 04:21 PM
sweet, Im sure if you tune it youll get a honest 80- 81mph out of her.

a 2-3 foot chop would do ya some justice too.

Shanghied Again
09-01-2002, 08:13 PM
Lil Griz, I liked the 30 pitch Bravo, I had 79mph out in Kentucky and 81 was my best I ran 77-78 most of the time. Feels great don't it? Totally different boat! The 22ZX runs better after 72mph. Best Of Luck With her and may the force be with you! You are now the top dog with a 22ZX on the block!

Lil Grizz
09-01-2002, 08:22 PM
Yes Frank this thing is so much easier to drive at 70+ than it was at 60. Its just smoother over rough water, but it now needs much more slowing down room. The strangest thing I noticed first was how it "coasts" when pulling throttle off. Once you get above 70 it likes to stay there even with no throttle. Scared me to death the first time but once its done with its little glide it just plops down and stops.

Shanghied Again
09-01-2002, 09:04 PM
Wait until you get use to it, That is one thing I miss is the speed of the 22ZX, I love the ride of the 26 but I miss the speed of the 22ZX.

Bryan Tuvell 33ZX
09-01-2002, 09:55 PM
Man I bet Todd and Ted were gripping to see you hang with them.....

I have known of both "cats in the bag" for awhile.... can not tell how though! Everyone swears not to tell! wink
Thank goodness a ZX did it in style at Eufala...
Great photos too send more and more data on the install, if ya have all the details and pictures I think you qualify for the post Harbormaster mentioned... New T-Shirt for LGriz.....
You got my vote! eek!
Bryan

HyperDonzi
09-01-2002, 09:58 PM
i am jealous. 80 mph should be fast enough for you THIS SEASON.... :D

Lil Grizz
09-01-2002, 10:15 PM
Bryan, It was good to be able to run next to the Hp500s :) I am really pleased with my results and the gang was verry impressed with the ZX. I now wonder what headers, cam, heads, and a dry sump will do for me... hehe. Wonder how hard it would be to put this whipple on a hp500 long block. Nahhhhhh Im just kidding!

Bryan Tuvell 33ZX
09-01-2002, 10:25 PM
LilGrizz
Your post was the highlight of my day, short of getting L..D this morning! :)
I am sure you will give Big Griz some competition now.... :D
Best of luck.
Bryan

Lil Grizz
09-01-2002, 10:30 PM
I doubt I can give him a good run. Every time I get close he pulls another 10mph out of thin air.

ToonaFish
09-02-2002, 01:49 AM
To sum up Lil Griz's article...

That sucker screams!

Nearly got whiplash the first time he zoomed by... no one had told me about the cat in a bag and I was floored! You did a great job of handling the extra speed and showing how classic a Z boat truly is!

Bunches,

Celene 'and they still could take photos!'

BigGrizzly
09-03-2002, 12:32 AM
I am a proud Big Grizzly. Lil Grizz did this on his own. He has learned well, and now is teaching me. The best part is he driving well and safe.

Randy, owner of Donzis since 1966

Forrest
09-03-2002, 09:32 AM
Scott, you made it back to Miam-ah?

Damn! Most of us never saw the 75+ mph gang except at the motel.

waleyetwo
09-03-2002, 12:11 PM
sweet lil grizz good luck keep it on the right side. eek!

Digger
09-04-2002, 07:37 AM
very nice Lil Grizz, congrats and have fun!

Forrest
09-04-2002, 09:48 AM
Todd is there big time!

Bummer on the popped Carlisle, and even more of a bummer having to do the pine-straw job. Oh well, it could be worse. Maybe we'll take the X-18 with us to Ginny's brother's hitching in Orlando this weekend and make a stop at the Suwanee on the way back.

-------------

Forrest - Have spare will travel.

Paul Storti
09-04-2002, 10:35 AM
Lil Grizz,

Congrats on the new blower must be fun to go around hauling ass!!! I have been thinking about doing the same to my 22ZX but I was wondering what made you go with the whipple vs a procharger and how much did the kit cost?

Lil Grizz
09-04-2002, 12:38 PM
I went with whipple because their kit was the only one designed specifically for the 7.4 mpi.
The other kits were more of a universal BBC with EFI specific components. I had heard good things about the procharger but from talking to everyone they said whipple had better durability and a much more reliable fuel system. I was advised to purchase a better fuel pump if I got a procharger, but then again I was told to change my heads for the whipple. I would have liked to have gone with a Vortech but they dont have a kit that could work on my engine as of yet. Shangied Again had a procharger on his 7.4 so hes the guy to ask about first hand experience with them. I think the Whipple has a much better appearance over the other kits, as you can see from the pics it doesnt look out of place. The only headache is the Whipple kits need for substantial ECU tuning, but thats how they solved the fuel system headaches the other brands have. You can get an idea about pricing and kit info by visiting www.whipplesuperchargers.com (http://www.whipplesuperchargers.com) and www.procharger.com (http://www.procharger.com)