• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

My Twin Turbo 6.5 (GM4 & GM8)

DZZ71

DZZ71

"Living The 6.5 Dream"
Messages
458
Reaction score
0
Location
Alberta,Canada
My first engine i rebuilt completly myself. I decided to Mount a secondary turbo on the drivers side. The other mods i did on this engine are lower compression, over sized pre cups, Split intake and cross over pipe delete. The intake i built has a divider so each side of the engine is independently powering each turbo so there is no interference with boost if one turbo is lagging. For the cross over pipe being gone each turbo is going to each stack with 4 inch pipe from the down pipes. Just though i would share what i have been tinkering with. I still have a few things to finnish on it. If this set up works well my other engine is going to get a similer set up with a very beefed up bottem end.

http://youtu.be/CkGhv0_nbfA
 
Last edited by a moderator:
As soon as i get some guages for the turbos i well post what im getting for boost on each side.
 
Looks cool. What turbos are you running?

How long did it take for the build up?

Looks like you need to get some fresh are for those intakes.

Colby
 
Turbos are gm4 and gm8 took me about 3 months working on it here and there. I was working away most of the summer so i couldent do much.
 
turbonator said:
did you use 2 pass. side manifolds to do that? did you know that you can buy hole saws that are 5''?:hihi:
Click to expand...

Haha I used the existing manifold on the drivers side by flipping it around and for the passenger I capped the cross over pipe end and that was it. Fitting in the stacks was one of the most frustrating parts of the project besides getting the scanner to work. Building a 4 inch exhaust to wrap around the fule tank isent fun. I plan on mounting my batterys in between the stack so I can get better spot for
My drivers filter to sit. So the reason for the big hole is for cables to run through with out touching the exhaust :p
 
DZZ71 said:
The intake i built has a divider so each side of the engine is independently powering each turbo so there is no interference with boost if one turbo is lagging. .

]
Click to expand...
I'm a little confused with that.
How would the intake be powering the Turbo's ? Also if you split the intake so the r/s turbo is providing boost for the r/s and L/s l/s and you are running 2 different turbos that spool differntly I would think that would put alot of uneven pressure on the crank.
 
Having different boost levels would put some uneven pressure on the crank, but the fuel table isn't based on boost, its based on throttle position, so both halves would be getting the same fuel level, so I'd think the pressure would be close. The boost guarantees it to completely burn, and cooler too with more air moving through.

The side with more boost would probably have less restriction to make said boost, so It may even out? Confused myself.... hmm... :)

Can't wait to hear about some road trip data.
 
Acesneights1 said:
I'm a little confused with that.
How would the intake be powering the Turbo's ? Also if you split the intake so the r/s turbo is providing boost for the r/s and L/s l/s and you are running 2 different turbos that spool differntly I would think that would put alot of uneven pressure on the crank.
Click to expand...

Sorry if i dident quite explane it well, I have some photos so you can see what i did. As for the different turbos? there isent much difference between a 4 and a 8. I can see where your coming from when your talking about the uneven pressures on the crank but im not pushing this engine to the absolute limit. so if one spools a bit slower im sure it will be okay if not i guess you all will find out. never hurts to re-invent the wheel :) The bottem end on this truck is completly stock and has some pretty bad cracks. The olny reason i built it was strictly for testing. If i like the lower compression, over sized precups, Cold start ups, Spool up time with the twins,fule ecomomy and How the paint sticks to the engine. I want to be sure it's what i want when i build my racing engine. Caues its gonna cost alot more then what i put into this one and i wanna make sure its what i want in the long run.


turbo016.jpg

dec16006.jpg

dec16011.jpg
 
Acesneights1 said:
I'm a little confused with that.
How would the intake be powering the Turbo's ? Also if you split the intake so the r/s turbo is providing boost for the r/s and L/s l/s and you are running 2 different turbos that spool differntly I would think that would put alot of uneven pressure on the crank.
Click to expand...

Probably meant to say "powered by" instead of "powered".

I'm interested in what it looks like under the "upper plenum"....

edit:
Dang, posting while I was typing!
 
Matt Bachand said:
Having different boost levels would put some uneven pressure on the crank, but the fuel table isn't based on boost, its based on throttle position, so both halves would be getting the same fuel level, so I'd think the pressure would be close. The boost guarantees it to completely burn, and cooler too with more air moving through.

The side with more boost would probably have less restriction to make said boost, so It may even out? Confused myself.... hmm... :)

Can't wait to hear about some road trip data.
Click to expand...


I have been driving it but unfortunatly i think my injection pump is done for, It wont take a re learn it just dies and when i put it in drive it also dies with out giving it a bit of throttle. As for the drving part its slower spooling thats for sure but it pulls alot harder on the top end already then my hx35 did, Also there is next to nothing for smoke compared to the HX35. must be pushing more air to burn cleaner. Im gonna try mount the guages tomorrow so i know what im putting out for boost.
 
that is some nice fab work..... we are doing the same thing with the batts on our ''junior truck'' build, it gives plenty of room under the hood for locating goodies... we will build a 16'' wide box the width of the box for the batts, WMI system and resevior.... it will be 2 inches higher than the batts and located to the top of the box, like a tool box that sits on the top of the bed, just smaller.
 
Ok how much bigger are the pre cups and how much lower is the compression if you would like to share that information. The rest is real nice, and I would be interested in the data on the drive and pulling part when you get some time on the motor.
 
Why have independent turbos(If I'm reading that right)

Why not compounds? (smaller spool the larger)

then in your situation you wouldn't be putting the uneven pressure on opposite banks...
 
You must log in or register to reply here.
Back
Top