It is currently Mon Jul 14, 2025 4:51 am




Reply to topic  [ 34 posts ] 
 GTR 37 EFI RPM Question 
Author Message
MMT Member

Joined: Fri Oct 01, 2010 2:11 pm
Posts: 15
Location: SE Louisiana
Post GTR 37 EFI RPM Question
Just a quick question for you guys...I just picked up my new GTR rig with 37 EFI engine running the three blade prop. Whats the normal RPMs this thing should be running on top end? If I run it trimmed out like my old GTR, this thing is screaming at 4700 RPM. If I bump the trim down one notch it runs around 43-4400.
Just want your guys' opinions.

Thanks!


Mon Oct 12, 2015 1:40 pm
Profile
MMT 1000 Club
User avatar

Joined: Wed Jul 13, 2011 6:23 pm
Posts: 4898
Location: Bourg LA
Post Re: GTR 37 EFI RPM Question
Mines ran well at 4100/4200


Mon Oct 12, 2015 2:01 pm
Profile
MMT 1000 Club
User avatar

Joined: Wed Jan 02, 2013 12:59 pm
Posts: 1793
Location: Clear Lake, Tx
Post Re: GTR 37 EFI RPM Question
Best I've seen is 4140, but I haven't ran it empty and it only has 10hrs

Sent from my SM-G900V using Tapatalk


Mon Oct 12, 2015 2:25 pm
Profile WWW
MMT Pro Member

Joined: Tue Nov 19, 2013 7:15 pm
Posts: 59
Location: Baton rouge area
Post Re: GTR 37 EFI RPM Question
You need the 11p prop. Mine was all over the rev limiter at 4780 w the 10 pitch, drpped to 41-4300 trimmed out now w the 11

_________________
19x48 rickey aucoin bateau
37efi gtr


Mon Oct 12, 2015 2:47 pm
Profile
MMT Member

Joined: Fri Oct 01, 2010 2:11 pm
Posts: 15
Location: SE Louisiana
Post Re: GTR 37 EFI RPM Question
Thanks for the info! Greatly appreciated


Mon Oct 12, 2015 3:42 pm
Profile
MMT F.E.
User avatar

Joined: Tue Feb 05, 2013 8:39 pm
Posts: 764
Post Re: GTR 37 EFI RPM Question
I gain speed all the way to ~4250rpm with the 11p 3-blade; after that it's picking up rpms but losing speed.


Mon Oct 12, 2015 8:14 pm
Profile
MMT 1000 Club

Joined: Sat Dec 15, 2012 9:43 pm
Posts: 2225
Location: Baytown, Tejas
Post Re: GTR 37 EFI RPM Question
I don't peak speed till 4600-4700. Try to keep it around 4500 but I drop 2-3 mph. Having my prop rebuilt right now with a little more added to it to hopefully bring my rpm down


Tue Oct 13, 2015 9:22 am
Profile
MMT 1000 Club
User avatar

Joined: Wed Jan 02, 2013 12:59 pm
Posts: 1793
Location: Clear Lake, Tx
Post Re: GTR 37 EFI RPM Question
Is yours 20 or 11 pitch jordan

Sent from my SM-G900V using Tapatalk


Tue Oct 13, 2015 10:49 am
Profile WWW
MMT 1000 Club

Joined: Sat Dec 15, 2012 9:43 pm
Posts: 2225
Location: Baytown, Tejas
Post Re: GTR 37 EFI RPM Question
11 I think is whats stamped on it. Not positive though. Baumam will have it finished tomorrow, said he would re work it to get my rpms down without loosening speed so we shall see


Tue Oct 13, 2015 11:16 am
Profile
MMT 1000 Club
User avatar

Joined: Thu Aug 27, 2009 3:17 pm
Posts: 2624
Location: League City, Texas. It's where I play.
Post Re: GTR 37 EFI RPM Question

_________________

Kool-Aid Brigade


www.southernfowler.com


Tue Oct 13, 2015 11:51 am
Profile
MMT Elite Member
User avatar

Joined: Wed Jan 14, 2009 7:23 am
Posts: 6233
Location: Tarkington, TX
Post Re: GTR 37 EFI RPM Question

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


Tue Oct 13, 2015 12:21 pm
Profile
MMT 1000 Club

Joined: Sat Dec 15, 2012 9:43 pm
Posts: 2225
Location: Baytown, Tejas
Post Re: GTR 37 EFI RPM Question
$120 is what he does mine for. The ones he's done in the past for me turned out good, the last one was a bit to big and I couldn't spin it and he rebuilt it again for free so it was right. He's normally pretty quick to, I dropped it off yesterday and it will be ready tomorrow

I was going to get a GT 2 blade but they were out of stock and I needed it by this week.


Tue Oct 13, 2015 4:47 pm
Profile
MMT 1000 Club

Joined: Sat Dec 15, 2012 9:43 pm
Posts: 2225
Location: Baytown, Tejas
Post Re: GTR 37 EFI RPM Question


Tue Oct 13, 2015 4:51 pm
Profile
MMT F.E.
User avatar

Joined: Tue Feb 05, 2013 8:39 pm
Posts: 764
Post Re: GTR 37 EFI RPM Question


Tue Oct 13, 2015 6:35 pm
Profile
MMT 1000 Club
User avatar

Joined: Wed Jan 02, 2013 12:59 pm
Posts: 1793
Location: Clear Lake, Tx
Post Re: GTR 37 EFI RPM Question
He's got a gtr

Sent from my SM-G900V using Tapatalk


Tue Oct 13, 2015 7:23 pm
Profile WWW
MMT F.E.
User avatar

Joined: Tue Feb 05, 2013 8:39 pm
Posts: 764
Post Re: GTR 37 EFI RPM Question
Oh. . .um, yeah.

Aside from me being an idiot. . .my post should still hold true. I think he's seeing a lot of "false" rpms and slippage.


Tue Oct 13, 2015 8:17 pm
Profile
MMT 1000 Club

Joined: Sat Dec 15, 2012 9:43 pm
Posts: 2225
Location: Baytown, Tejas
Post Re: GTR 37 EFI RPM Question
No idea what any of that means. I think it was an 11 pitch, not 100% positive though. Then again I'm not very sure what's a high or low pitch prop either... Lol
My best speeds always came with the shaft being almost ecactly half way out, where the prop gets that good "hum" . ive tried running at the 4200 range but i still have alittle over a quarter throttle left and the engine dont even sound close to opened up good. Overall I'm more than happy with the way it runs though. Before I took my prop to be rebuilt I could hit 29mph completly empty but that was at 4700 rpm..that sucker was pretty worn out too. New one on I can do 31ish at about 4600 but that's still way high. I can't complain though, I don't know of many other boats as big as mine that can break 30 stock, and I know I got a few pretty bad hooks too.


Wed Oct 14, 2015 2:35 am
Profile
MMT Elite Member
User avatar

Joined: Wed Jan 14, 2009 7:23 am
Posts: 6233
Location: Tarkington, TX
Post Re: GTR 37 EFI RPM Question
Quack I highly doubt you have an 11P prop spinning that fast. as for max RPM. How many people you see in outboards worried about RPM? It is all about speed. 4700 RPM is not a bad thing.. Back in 2009-2010 ish people thought stock engines that spin over 4500 were going to explode so the propped them so much where they kept them at 4k-4200 ish. Well that year many engines came apart from being lugged from too much prop.... Let that sucker sing.. Over propping is the same concept as trying to run 38's on a stock geared Z-71.

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


Wed Oct 14, 2015 5:11 am
Profile
MMT 1000 Club
User avatar

Joined: Wed Jan 02, 2013 12:59 pm
Posts: 1793
Location: Clear Lake, Tx
Post Re: GTR 37 EFI RPM Question
Agreed, you got a 10p

Sent from my SM-G900V using Tapatalk


Wed Oct 14, 2015 6:42 am
Profile WWW
MMT 1000 Club

Joined: Sat Dec 15, 2012 9:43 pm
Posts: 2225
Location: Baytown, Tejas
Post Re: GTR 37 EFI RPM Question
I'll look at it and double check when I get it back. Should be done today. No idea what it is I know nothing about props lol I just took a guess at it being 11.


Wed Oct 14, 2015 2:00 pm
Profile
MMT 1000 Club
User avatar

Joined: Wed Jan 02, 2013 12:59 pm
Posts: 1793
Location: Clear Lake, Tx
Post Re: GTR 37 EFI RPM Question
I'll look at mine and text you what it's stamped, it's for sure 11p

Sent from my SM-G900V using Tapatalk


Wed Oct 14, 2015 2:14 pm
Profile WWW
MMT 1000 Club
User avatar

Joined: Thu Aug 27, 2009 3:17 pm
Posts: 2624
Location: League City, Texas. It's where I play.
Post Re: GTR 37 EFI RPM Question
Whats the consensus.

10p = Not stamped
11p = Stamped 11p

???????????

_________________

Kool-Aid Brigade


www.southernfowler.com


Wed Oct 14, 2015 2:23 pm
Profile
MMT 1000 Club

Joined: Mon Dec 31, 2012 11:07 pm
Posts: 4820
Location: West Monroe, LA
Post Re: GTR 37 EFI RPM Question
The 11p usually doesn't have any marks. The 10p has it marked.


Wed Oct 14, 2015 2:43 pm
Profile
MMT Elite Member
User avatar

Joined: Wed Jan 14, 2009 7:23 am
Posts: 6233
Location: Tarkington, TX
Post Re: GTR 37 EFI RPM Question
spin your prop 1 revolution.... the theoretical forward movement should be either 10 or 11" :lol:

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


Wed Oct 14, 2015 3:19 pm
Profile
MMT Addict

Joined: Tue Oct 08, 2013 12:25 am
Posts: 668
Location: Where the mud flats are
Post Re: GTR 37 EFI RPM Question
you have a 10p for sure. a 11p you would be at 4400 rpms at the most

_________________
18x48 extreme with 37 gtr
past boats
stage 2 37 gtr on 18x48 sportsman fab
Gen 3 36 prodrive on 18x48 sportsman fab
Gen 2 36 prodricr on cc 18x48 sportsman fab
07 gtr on 16x54 alweld


Wed Oct 14, 2015 3:47 pm
Profile
MMT Super Elite Member

Joined: Fri Dec 18, 2009 8:10 pm
Posts: 16915
Location: Rowlett, TX
Post Re: GTR 37 EFI RPM Question


Wed Oct 14, 2015 4:20 pm
Profile
MMT 1000 Club

Joined: Sat Dec 15, 2012 9:43 pm
Posts: 2225
Location: Baytown, Tejas
Post Re: GTR 37 EFI RPM Question
Couldn't find a stamp on it anywhere. I could a sworn I saw something on there before. Who knows though.

Sent from my SAMSUNG-SM-G870A using Tapatalk


Wed Oct 14, 2015 5:55 pm
Profile
MMT 1000 Club
User avatar

Joined: Wed Jan 02, 2013 12:59 pm
Posts: 1793
Location: Clear Lake, Tx
Post Re: GTR 37 EFI RPM Question
There both stamped there both a number in the 40s

Sent from my SM-G900V using Tapatalk


Wed Oct 14, 2015 6:08 pm
Profile WWW
MMT 1000 Club
User avatar

Joined: Wed Jan 02, 2013 12:59 pm
Posts: 1793
Location: Clear Lake, Tx
Post Re: GTR 37 EFI RPM Question


Mine has 41 on every blade. Gt said the 10p has 45 or 46 I don't remember. Maybe these are just on the new castings.

Sent from my SM-G900V using Tapatalk


Wed Oct 14, 2015 7:13 pm
Profile WWW
MMT 1000 Club
User avatar

Joined: Thu Aug 27, 2009 3:17 pm
Posts: 2624
Location: League City, Texas. It's where I play.
Post Re: GTR 37 EFI RPM Question
I have two 3blades that are completely blank... So yeah...
With a stage one motor I cruse about 4300rpm with a moderate load so I assume 11p

_________________

Kool-Aid Brigade


www.southernfowler.com


Wed Oct 14, 2015 7:24 pm
Profile
MMT 1000 Club

Joined: Sat Dec 15, 2012 9:43 pm
Posts: 2225
Location: Baytown, Tejas
Post Re: GTR 37 EFI RPM Question
Yeah mine doesn't have anything on it I've looked everywhere.


Wed Oct 14, 2015 7:27 pm
Profile
MMT 1000 Club
User avatar

Joined: Wed Jan 02, 2013 12:59 pm
Posts: 1793
Location: Clear Lake, Tx
Post Re: GTR 37 EFI RPM Question
I think yours are 10p james

Sent from my SM-G900V using Tapatalk


Wed Oct 14, 2015 8:07 pm
Profile WWW
MMT 1000 Club

Joined: Sat Dec 15, 2012 9:43 pm
Posts: 2225
Location: Baytown, Tejas
Post Re: GTR 37 EFI RPM Question
It is a 10. It was in some real "fine print" but I found it and it is a 10


Thu Oct 15, 2015 10:58 pm
Profile
MMT 1000 Club

Joined: Sat Dec 15, 2012 9:43 pm
Posts: 2225
Location: Baytown, Tejas
Post Re: GTR 37 EFI RPM Question
I ran that prop I got reworked today and its going to be perfect for hunting season. The rpms are a bit different but the hole shot on it is freaking crazy. It stayed right at 27mph on the rev limiter and steady 28.5-29mph in the 4500 range so what ever he did to the prop seems to be working. Now back to that hole shot though..I wasn't really prepared for what happened, when I got on it to hop and go it rocked me enough to loose my balance and have to stop so i could stand up straight and grab the grab bar and try again lol. That big heavy ass boat was on plane in 1 boat length.

I never really noticed it before with the old motor as it never broke 24mph but now that I got some speed behind me that tapered chine does not like to stay straight in even the slightest turn past 25mph even in deep water.


Sun Oct 18, 2015 9:34 pm
Profile
Display posts from previous:  Sort by  
Reply to topic   [ 34 posts ] 

Who is online

Users browsing this forum: Google [Bot] and 108 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:  
cron