It is currently Thu Apr 18, 2024 10:42 pm




Reply to topic  [ 23 posts ] 
 worth modding a 2008 GT? 
Author Message
MMT Pro Member

Joined: Wed Sep 16, 2015 11:50 am
Posts: 284
Post worth modding a 2008 GT?
I have a 2008 GT (non reverse). its the old style motor that doesn't have the cav plate. It has 51 original hours. Is it worth it to put the couple thousand into the mods? I'm not worried about the lack of reverse, mostly concerned about the performance and the "old" style frame.


Tue Jun 06, 2017 10:10 am
Profile
MMT 1000 Club
User avatar

Joined: Wed Oct 07, 2009 8:18 pm
Posts: 4310
Post Re: worth modding a 2008 GT?
performance will come from the block and yes, old or new frame, you will see a huge difference.


Tue Jun 06, 2017 10:31 am
Profile
MMT F.E.
User avatar

Joined: Tue Aug 26, 2014 10:36 am
Posts: 822
Location: Jefferson TX
Post Re: worth modding a 2008 GT?
IMO at least heads carb and exhaust, and yes it will feel like a new motor. When I did mine I gained 5 mph then upgraded the coils to the 4700, and got a couple more.

_________________
SEAARK FX 2472 CC Merc 150HP 4Stroke(CypressCadillac)
Uncle J Custom - 19x54 CC Skiff w/40XD GTR


Tue Jun 06, 2017 10:33 am
Profile
MMT 1000 Club
User avatar

Joined: Tue Jan 13, 2009 6:42 pm
Posts: 2377
Location: West Coast Wisconsin
Post Re: worth modding a 2008 GT?
A lot of folks mod MB and they don't have reverse. Hell that GT was faster 1-3mph out of the box then a lot of them according to some folks.


Tue Jun 06, 2017 10:55 am
Profile
MMT Elite Member
User avatar

Joined: Wed Jan 14, 2009 7:23 am
Posts: 6233
Location: Tarkington, TX
Post Re: worth modding a 2008 GT?
It will be a good improvement. I like to do heads, cam, and exhaust. It's a solid reliable setup. The stock carb can be turned up to spin the needed RPM for the increase and still have over rev protection.

_________________
Bayou Surface Drive
337-351-0362
Tarkington, TX 77327


Tue Jun 06, 2017 12:06 pm
Profile
MMT Pro Member

Joined: Wed Sep 16, 2015 11:50 am
Posts: 284
Post Re: worth modding a 2008 GT?


Tue Jun 06, 2017 12:17 pm
Profile
MMT Pro Member

Joined: Wed Sep 16, 2015 11:50 am
Posts: 284
Post Re: worth modding a 2008 GT?
also, I run a ton of more residential water. Don't want to piss off my neghbors with a voodoo exhaust. What would you recommend for a more neighbor friendly pipe?


Tue Jun 06, 2017 12:18 pm
Profile
MMT Elite Member
User avatar

Joined: Wed Jan 14, 2009 7:23 am
Posts: 6233
Location: Tarkington, TX
Post Re: worth modding a 2008 GT?
Your average motor that spins 4750 and below is more than sufficient with stock connecting rods. Headwork consists of Decking(milling/shaving), porting, polishing, new valves, 3 angle valve job, shimmed valve springs, cut valve spring pockets so all valves have the same pressure, deshroud the valve seat area, and new valve stem seals.
I have my own cam grind that works very well and I can adjust the timing to dial in the power band. The carb is usually pretty close with stock jetting, but can be rejected if need be. I also adust governor to be about 250 rpm above what the boat will run under load to keep the governor from surging and holding the engine back.
Exhausts are your preference. Stock surprisingly works decent with a modded motor, then the BPS Q is a little more flow and not much louder, then you have a stainless works Good flow and moderately loud, then the Voodoo is the most flowing exhaust. With that comes power and noise.

If you'd like pricing on anything give me a PM or call, 337-351-0362

_________________
Bayou Surface Drive
337-351-0362
Tarkington, TX 77327


Tue Jun 06, 2017 12:35 pm
Profile
MMT 1000 Club

Joined: Sun Dec 14, 2014 2:21 pm
Posts: 3214
Post Re: worth modding a 2008 GT?
I modded an 08 engine with 501 hours on it and got decent power improvements and it's still running fine


Sent from my iPhone using Tapatalk


Tue Jun 06, 2017 4:37 pm
Profile
MMT 1000 Club
User avatar

Joined: Wed Oct 07, 2009 8:18 pm
Posts: 4310
Post Re: worth modding a 2008 GT?


Wed Jun 07, 2017 4:11 am
Profile
MMT Elite Member
User avatar

Joined: Wed Jan 14, 2009 7:23 am
Posts: 6233
Location: Tarkington, TX
Post Re: worth modding a 2008 GT?
On average I have .045 removed. But you can safely go to .065 depending. My last EFI was .065 decking and it has 175 PSI cranking. I know its not a huge indicator, But its an idea. A rod/piston motor will have 200 PSI cranking ish....

_________________
Bayou Surface Drive
337-351-0362
Tarkington, TX 77327


Wed Jun 07, 2017 5:04 am
Profile
MMT 1000 Club
User avatar

Joined: Tue Jan 13, 2009 6:42 pm
Posts: 2377
Location: West Coast Wisconsin
Post Re: worth modding a 2008 GT?
MaXXis, nailed it.


Wed Jun 07, 2017 6:45 am
Profile
MMT Addict
User avatar

Joined: Sat May 10, 2014 5:50 pm
Posts: 660
Location: Arkansas
Post Re: worth modding a 2008 GT?
Some of the old hands correct me if i'm wrong. There were at least two different styles of stock rods through the years. The current ones are good for at least 4700 rpm unless of course there is a casting defect.(which is never heard of with anything briggs :roll: ) but the old styles werent so good. I belive these rods may have been black? With an 08 I doubt he will have the motor with the updated rods and definitely will not have anything but the gov to keep him from spinning way too many rpm. Except those old valve springs. Probably start to float around 4400 lol

_________________
15x36 Go Devil Duck Skiff with a Go Devil Longtail.


Thu Jun 08, 2017 11:02 am
Profile
MMT 1000 Club
User avatar

Joined: Wed Oct 07, 2009 8:18 pm
Posts: 4310
Post Re: worth modding a 2008 GT?
I had an 07 36 on my PD and it would spin 5000 plus with stock internals before I swapped to the Kawasaki for less case leaks.


Thu Jun 08, 2017 11:58 am
Profile
MMT Elite Member
User avatar

Joined: Wed Jan 14, 2009 7:23 am
Posts: 6233
Location: Tarkington, TX
Post Re: worth modding a 2008 GT?
Anything above 5k is iffy on a stock rod. Gray or black rods I'm. It afraid to spin 4750 all day.


Sent from my iPhone using Tapatalk

_________________
Bayou Surface Drive
337-351-0362
Tarkington, TX 77327


Thu Jun 08, 2017 1:17 pm
Profile
MMT Pro Member

Joined: Wed Sep 16, 2015 11:50 am
Posts: 284
Post Re: worth modding a 2008 GT?
I made the jump and am doing the mods. Decked heads and all valves etc that goes with it, cam and carb. I was planning on gutting the stock exhaust but am reading a lot of poor reviews. I know air flow is what makes an exhaust worth buying, but with all of the different brands out there and they ALL say hey are they best, I kinda get lost in what is what. I'm hoping to get a used one that won't rattle my ear drums but will still allow my motor to breathe. What should I be keeping my eye out for?


Wed Jul 12, 2017 6:59 pm
Profile
MMT Super Elite Member

Joined: Fri Dec 18, 2009 8:10 pm
Posts: 16915
Location: Rowlett, TX
Post Re: worth modding a 2008 GT?


Wed Jul 12, 2017 7:06 pm
Profile
MMT Elite Member
User avatar

Joined: Wed Jan 14, 2009 7:23 am
Posts: 6233
Location: Tarkington, TX
Post Re: worth modding a 2008 GT?
All of the exhausts get LOUD once the heads are ported, and you have a cam allowing more air in and out.

Quietest is the BPS Q...

_________________
Bayou Surface Drive
337-351-0362
Tarkington, TX 77327


Thu Jul 13, 2017 6:36 am
Profile
MMT F.E.
User avatar

Joined: Tue Aug 26, 2014 10:36 am
Posts: 822
Location: Jefferson TX
Post Re: worth modding a 2008 GT?
From being around all these Mud Motor crazies, and listening to and watching different situps. BPS Q is a good choice but a word of advice. Mine kept cracking in and around welds. When and if you bolt on a BPS Q, tighten bolts at head(exhaust flange) Then bolts on the brackets on the block. then brackets to muffler. Stopped my cracking problem when I did it this way because the holes didn't line up properly. One good drill bit later it all bolted up and did not have anything in a bind. And use the VW compression type exhaust gaskets. IMO

_________________
SEAARK FX 2472 CC Merc 150HP 4Stroke(CypressCadillac)
Uncle J Custom - 19x54 CC Skiff w/40XD GTR


Thu Jul 13, 2017 8:02 am
Profile
MMT Elite Member
User avatar

Joined: Wed Jan 14, 2009 7:23 am
Posts: 6233
Location: Tarkington, TX
Post Re: worth modding a 2008 GT?

_________________
Bayou Surface Drive
337-351-0362
Tarkington, TX 77327


Thu Jul 13, 2017 9:32 am
Profile
MMT Pro Member

Joined: Wed Sep 16, 2015 11:50 am
Posts: 284
Post Re: worth modding a 2008 GT?
another side question. Ive noticed that "dual" pipes out the back are a thing of the past. Only seems like motors prior to 2011 had them. Any reason for that? is it more for function or marketing by the custom shop guys?


Thu Jul 13, 2017 12:56 pm
Profile
MMT Super Elite Member

Joined: Fri Dec 18, 2009 8:10 pm
Posts: 16915
Location: Rowlett, TX
Post Re: worth modding a 2008 GT?
They were commonly installed on the factory modded mb's. Not sure if mb even offers them anymore, but there are quite a few more options on the market now too. The duals were loud as shit, and they were not seeing the same gains with them as some of the other options.


Thu Jul 13, 2017 1:13 pm
Profile
MMT F.E.
User avatar

Joined: Tue Aug 26, 2014 10:36 am
Posts: 822
Location: Jefferson TX
Post Re: worth modding a 2008 GT?
I got a set of duals that need a little welding-$120.00 that is including shipping, if you want them.

_________________
SEAARK FX 2472 CC Merc 150HP 4Stroke(CypressCadillac)
Uncle J Custom - 19x54 CC Skiff w/40XD GTR


Fri Jul 14, 2017 7:56 am
Profile
Display posts from previous:  Sort by  
Reply to topic   [ 23 posts ] 

Who is online

Users browsing this forum: No registered users and 341 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to: