Vortec L31 MARINE MANIFOLD project! Q&A

Performance modifications, tips & tricks

Moderators: Eric@PPE, James B., flyingpolarbear, Dev

99turbo
Posts: 31
Joined: Tue Nov 27, 2012 12:05 am

MAF

Post by 99turbo »

A James B. were you running enough boost that you had to upgrade the MAF to get more Hz?
If so could you tell me what you upgraded to, and if I need to worry pinnouts/rewiring and such.....

OR how bout one from a 2001-02 chevy 2500 6LTR?

Any help is greatly appropriated,
Thanks.

davkenrem
Posts: 16
Joined: Sun Aug 13, 2006 7:55 pm

Post by davkenrem »

Formyboat wrote:Could somebody tell me the part number of this marine manifold preferably the lower section or where to get one and what term to use I have had no luck at all new or 2 nd hand
Thanks James
http://www.michiganmotorz.com/indmar-al ... 11195.html

rmoschilli
Posts: 1
Joined: Mon Apr 01, 2019 1:47 pm
Location: Kempner, Texas

Vortec Marine Manifold Post.

Post by rmoschilli »

I am currently caught between a rock and
Hard place.

Need to talk to someone who was involved in this project.

Can somebody help me out??

Thanks,

Rick

James B.
Moderator
Posts: 2823
Joined: Thu Apr 03, 1997 4:00 pm
Location: '98GMT400, '98GMT410, '99GMT420, '00GMT420

Re: Vortec Marine Manifold Post.

Post by James B. »

rmoschilli wrote:I am currently caught between a rock and
Hard place.

Need to talk to someone who was involved in this project.

Can somebody help me out??

Thanks,

Rick
Hello Rick, what would you like to know?

Aaron383
Posts: 1
Joined: Sat Jun 01, 2019 4:55 pm
Location: Hot springs

MArine intake

Post by Aaron383 »

HEY I was wondering if i could run my thermostat bypass to the already tapped hole in the intake water jacket by the egr port.

I would think it wouldn’t matter but would like a little input from the guys that have done this swap.
Also would like to know if anyone has had luck with blackbear tuning with this swap?

I’ve about got every thing finished to put the new stroker in my 99 2door Tahoe.

P.s. thank you guys for the detailed write up, has made this a pretty easy swap, I learned about the intake from a guy that must have read this forum.

I know it’s an old post, sorry for bringing it back 13 years later, prolly should have done ls swap

BrandonE
Posts: 2
Joined: Tue Apr 21, 2020 3:53 pm
Location: Northern Michigan

Post by BrandonE »

Well, I’m new here but used a lot of this thread to build a 406 small block with the marine intake and Black Bear Tune. Should have it going this weekend. Last couple guys had questions I could probably help with if you’re still out there. Stay tuned...

Hog
Posts: 5037
Joined: Tue Dec 11, 2001 4:00 pm
Location: 1997 Chev ECSB L31 350 1997 GMC Sierra SLE RCSB, Ontario

Re: Vortec L31 MARINE MANIFOLD project! Q&A

Post by Hog »

BrandonE wrote:
Tue Apr 21, 2020 3:59 pm
Well, I’m new here but used a lot of this thread to build a 406 small block with the marine intake and Black Bear Tune. Should have it going this weekend. Last couple guys had questions I could probably help with if you’re still out there. Stay tuned...
How'd it turn out?

peace
Hog

Thelochnessmonstah
Posts: 1
Joined: Fri Sep 25, 2020 7:09 pm

Bosch TMAP plug/adapter

Post by Thelochnessmonstah »

Am in the process of installing a marine intake, here, and found a small piece of information that might make it easier for anyone else who's out there still messing with these things.

The MAP sensor that comes on these intakes is a Bosch 4 wire TMAP sensor which uses a Bosch Kompakt 1.1m connector. The problem with using it is finding a pigtail for it. Turns out that Polaris uses a lot of these Bosch TMAPs, and Amazon has repair pigtails that fit it. Just got mine in today and I can confirm that it does fit.

https://www.amazon.com/dp/B07KY9X3ZT

The attached file has the TMAP pinout on it which will allow you to either come up with an adapter to your GM 3 wire Metri Pack 150 MAP or to cut and splice directly into your harness.

The nice thing about this is that you don't have to come up with a bracket for the stock MAP, and the Bosch TMAPs go out to 5 BAR if you're bonkers enough to need that sort of thing.
Attachments
Bosch-TMAP-Dimensions.png
Bosch-TMAP-Dimensions.png (15.65 KiB) Viewed 1234 times

JeremyNH
Posts: 2
Joined: Fri Oct 23, 2020 10:59 am

re: Bosch TMAP plug/adapter

Post by JeremyNH »

I'm also in the process of doing the swap and found a vendor that provides an adapter for converting the 4 wire Bosch TMAP to the 3 wire metripac. Basically they just provided a male TMAP to female MAP and ran the three wires necessary (+5V, 0, P signal) for a MAP and left the T signal unterminated turning the TMAP into a MAP. Seems the target audience is boosters since the TMAP can be found in 1, 2, 3, 3.5, and 4 bar variants with the same mounting and electrical interface making swapping to one with the desired P-to-V response for your level of boost easy. The Mercruiser manifold uses the 1 bar variant so use the adapter and the PCM will read the TMAP as if it were the stock MAP.

https://www.bmotorsports.com/shop/produ ... gIxyvD_BwE

CATaylor
Posts: 1
Joined: Wed Dec 09, 2020 9:19 am

Re: Vortec L31 MARINE MANIFOLD project! Q&A

Post by CATaylor »

Hey I am looking at doing the marine intake swap for my 2000 Escalade, does anyone know a good place to look for the marine intakes at a reasonable price?

Biggiecamp
Posts: 4
Joined: Mon Dec 21, 2020 9:19 am

Re: Vortec L31 MARINE MANIFOLD project! Q&A

Post by Biggiecamp »

Been lurking since 2005, finally signed up. Was gonna start this swap back in 2005, but life got in the way. I’ve acquired a manifold after a long delay, and am gonna embark on the swap. Former daily driver is now my toy, and I’m stubborn that I wanna do things a certain way with this truck. Therefore, it won’t be LS swapped. Glad to see this thread is still around, as it’s full of highly useful information. I will also be 411 swapping in the future. Just gotta get ahold of Lextech somehow, to my knowledge.

Biggiecamp
Posts: 4
Joined: Mon Dec 21, 2020 9:19 am

Re: Vortec L31 MARINE MANIFOLD project! Q&A

Post by Biggiecamp »

Question for those who have done this and are running boosted applications.
What effect, if any, does the boost pressure inside the plenum have on the FPR via its vacuum reference?
For the few running EGR in boosted applications, is there any side effects to EGR flow that you can distinguish?

Mjschneidy
Posts: 1
Joined: Thu Dec 31, 2020 1:46 pm

Re: Vortec L31 MARINE MANIFOLD project! Q&A

Post by Mjschneidy »

Are people still doing these conversions? I have a complete marine MPI setup with manifold, throttle body, fuel rails, injectors, all manifold mounted sensors, and harness that I’d be willing to sell. Thanks Mike

JeremyNH
Posts: 2
Joined: Fri Oct 23, 2020 10:59 am

Re: Vortec L31 MARINE MANIFOLD project! Q&A

Post by JeremyNH »

@Biggiecamp - You can likely get hold of Lextech on the GMT400 forum where he still seems to be active. I did the PCM411 swap a few months ago and he replied to my PM on that forum. He offers a pre-tuned PCM 411 (which I made use of) besides just the spreadsheet. About 3 hours work and unlike everything else I've done to the truck it actually made a noticeable difference (I haven't yet done the manifold swap - I have mine and it's ready but it's also winter in New England and I don't have a garage). Truck isn't more powerful but just runs noticeably better. Only hiccup is that when you do the swap and do the crank relearn you need to tell your local tuner that it is a 2002 Xvan else he won't be able to flash it after trying for a day. Also, don't use a dealership. They wanted $180 but the local non-chain shop did it for $58 so save some $$$.

Biggiecamp
Posts: 4
Joined: Mon Dec 21, 2020 9:19 am

Re: Vortec L31 MARINE MANIFOLD project! Q&A

Post by Biggiecamp »

Thanks. I have gotten in contact with Lextech, and got that sorted. My manifold isn’t in pristine condition, so it’s taking a few extra steps to get it ready.

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