Does Anyone Have Direct Experience With A 38ZX And 500EFI Whipples. Would Like To Find Out Real GPS Numbers. Thanks Ted.

Do you have 500 EFI motors?? If you Whipple them you can add 13-15 mph to what you have now.

Smitty,

I have 500EFI's now. They have 244 hrs and its time for valve spring preventive maintenace. They run and perform perfect. I am pondering the possiblility of adding Whipples to them this winter. The boat weighs in at 11,500 lbs dry. I was wondering how much more speed this heavy boat would actually pick up. I have HP transom assemblies and XR drives. Thanks for your input. Ted.

BTW, the boat runs 73-75 GPS now.

Here is what I recommend if you add the Whipples. Do a compression test before you teardown heads to get a baseline.



1. Go thru heads and install Inconel exhaust and severe duty intakes. Polish combustion chambers in the heads to remove chances of detonation.



2. use Fel-Pro MLS head gaskets and use ARP head stud kits.




3. Install separate water feeds for both intercoolers including sea strainers for both.



4. install vaccuum/boost guages on dash. Also install oil temp guages if you do not have them.


5. Put it all back together, get 6" more pitch on your props and rock and roll !!!



You should see at least 86-90 mph.

Also switch to royal purple drive oil in the drives.

You left out the part about buying 2 spare drives

Smitty;2314568]Here is what I recommend if you add the Whipples. Do a compression test before you teardown heads to get a baseline.



1. Go thru heads and install Inconel exhaust and severe duty intakes. Polish combustion chambers in the heads to remove chances of detonation.



2. use Fel-Pro MLS head gaskets and use ARP head stud kits.


I am still running the stock 500efi arp head bolts




3. Install separate water feeds for both intercoolers including sea strainers for both.

I ran one pick up into one sea strainer with 2 # 12's coming out to each innercooler



4. install vaccuum/boost guages on dash. Also install oil temp guages if you do not have them.

also water pressure gage


5. Put it all back together, get 6" more pitch on your props and rock and roll !!!

stock 500efi kit comes with 5 inch upper pully, prob low 700hp range,I went up 4 pitch sizes and 17mph at 7 1/4pds with other engine mods,I am also buzing my motor ,like you said 6 sizes



You should see at least 86-90 mph.

Also switch to royal purple drive oil in the drives.[/QUOTE]

Like Griff said spare drives

Hey guys-- he has XR's. The will live if he doesn't hammer it. Mine are living just fine.

You guys know it!!

I know the drives are the weak link, however, I am very easy on the sticks - never launch.

Would still mostly cruise around 40MPH. But occasionally run it up to top speed momentarily.

86-90MPH would be awesome!

Would it be cost effective to buy new Dart, Eldelbrock heads instead of re-doing mine? They are 7 years old and NOT fresh water cooled. Also, would the existing CMI headers work with the Whipples. Thanks Again!

BTW, I do compression tests every year. Last year they were all 165-175 lbs.

Aluminum heads will always help. I run the Edelbrocks, but had to spend a bunch of time getting them to flow right. I recommend darts or AFR's. If you go with aluminum make sure they are hard anodized to resist corrosion.

Believe me-- if you do this you will not cruise at 40 try more like 60-65 and then whack it up to 85 cuz u can !!! I cruise at 60 which is passing most boats and when I get someone trying me on for size I run it up to the mid 80's which sets the record straight 98% of the time!!!!

I like the way your thinking!

Now - If only Wal-Mart carried Whipples I could afford this.