trying to decide on street / tow twins

kawi600

kawi600

got Coal for Christmas
Ive got a 2nd gen with a phatshaft 62 on it and since it spends a lot of time in the city my beef is the off-idle smoke and lag.
Looking at putting twins on the truck and either I go the cheap route and slap a S475 on it like most people do and probably lose a little more low end spool in the process, or I sell the 62 and do something like a K27 / sxe369 thats supposed to have really decent low end and enough air on top for 600hp or so.
Has anyone tried a small twins set on a 5.9 and did it improve the low end enough to be worth the sacrifice of top end potential?
 
I have a 62/65/14 over 475/96/1.10 and westons 6x13s. It spools great, plenty of top end and tows great. I think it's a great setup, for me atleast. Even with cheap dap 7x10s they ran great.dynoed at 624/1240 but I was 20 pounds low on boost, I usually make a hair over 70 on the street and only made 50 on the dyno.
 
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the other thing is the 62 i got is from 2009 industrial says it prob doesnt have a 360 thrust on it so Im not sure how well it would hold up over time.
 
I bought mine used off of here, spent 60k miles in a compound setup and I have put another 30k on it on top of that. I'd run it until you notice to much shaft play
 
I was just thinking about this the other day, I have a 63/68 and it gets annoying in stop and go traffic. My thoughts were an hy35 and a 372 or a 471 with a 1.1 housing. K27 would be a nice setup but can’t find one reasonably. Hy guys basically give away lol
 
Garrett GTA4202, same physical size as an S400, same flange dimensions, and internally wastegated. Has a 75/82mm turbine, and typically can be had for under $900.
 
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Smokem said:
Garrett GTA4202, same physical size as an S400, same flange dimensions, and internally wastegated. Has a 75/82mm turbine, and typically can be had for under $900.
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Isn't the GTA the version that was supplied to CAT? I have one I need to do something with.

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I run a 62 over a 475/96/132 IIRC, with 7x10s and little pump work. Spools good,not to smoky, with the 5 speed you can kinda control it decent. But the set up works good, I use my truck for everything from DD to pulling tractors and skid loaders. Has enough air to make power and keeps egts in check pretty easy
 
yeah I get that the S475 and the GT4202 are cheap, but thats not a small tow twins setup its more like a small street hooligan setup, lol.
I dont need the extra top end I need the quick spool for towing heavy and getting around in the city without smoking people out.
high stall converter and cam helps but not enough for towing smoke free.
 
kawi600 said:
yeah I get that the S475 and the GT4202 are cheap, but thats not a small tow twins setup its more like a small street hooligan setup, lol.
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The standard S475 turbine is 88/96mm, the GTA4202 is 75/82mm which is nominally larger than the 73/80mm S300 turbine.
 
kawi600 said:
yeah I get that the S475 and the GT4202 are cheap, but thats not a small tow twins setup its more like a small street hooligan setup, lol.
I dont need the extra top end I need the quick spool for towing heavy and getting around in the city without smoking people out.
high stall converter and cam helps but not enough for towing smoke free.
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It's your secondary that controls that early on leaving a stop light.

I've ran a truck with the BD towing twin setup, which is a S300G that I think is 58/65 over a box 366 with the open turbine housing. I couldn't imagine going smaller than those, was almost instant psi.
 
How much spool do you lose putting another turbo under a single? I talked to a tech at industrial who said that turbo would 'run better as a single'.

I was looking at the BD twins too. even smaller than the PDD towing twin setup. Wish I had some butt-dyno data for comparison before I buy something.
 
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kawi600 said:
How much spool do you lose putting another turbo under a single? I talked to a tech at industrial who said that turbo would 'run better as a single'.

I was looking at the BD twins too. even smaller than the PDD towing twin setup. Wish I had some butt-dyno data for comparison before I buy something.
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If off idle is your biggest concern I'd put an HE351 on the manifold and throw something under it. Compounding generally does make the manifold charger respond a little slower but it wasn't a huge difference both times I did it. Before doing anything I'd spend a little more time dialing in your AFC, with a 62/65 smoke should be plenty controllable.
 
Can you guys think of anyone that makes a half-marmon flange downpipe for twins in the lower position in stainless steel?
I could probably find DIY kit somewhere but will be hard to find that flange in the same material.

What does changing the size of the primary turbo do, if the secondary is where your spool up is?
 
Didn't look, but the parts I needed when I put the HE351CW on my 24v came from stainless diesel (cold pipe to the intercooler), and Keating machine (flange for exhaust). Maybe they could help?

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What's up with that injection timing. 14 is damn near stock. I'd want that around 18 degrees.
I can't see how a 62mm is that smoky even with the automatic transmission. ??
I would adjust your AFC with the intent of taking away low air fuel, and bump that timing up. If you want compounds, the Garrett Batman mentioned is the way to go, but pre boost smoke won't change.
 
Injection timing is what I settled on after talking to weston years ago about the probs I was having trying to keep the smoke down driving in the city with a slightly larger than stock turbo and fuel. Settled on low timing and 155* injectors. seems to help a bit.
when I bump timing the lag is much worse on the bottom and the smoke is there until I remove it with the AFC. when I do that its really difficult to drive in the city especially when Im towing. What happens is if you dont accelerate instantly like the little cars do they zip around you and cut you off. most of the time they dont care if you can stop in time or not. Thats what Im dealing with and till I move out of this sh*thole thats what I got.
Would be easier to slap a S475 under what I got but it would be more difficult to drive it here.
 
For what it is worth I pulled my compounds off and kept the htt 62/13 as a single. Much snappier and easier to get on top the fuel than the compounds ever were. I can easily drive my dtt auto with zero smoke. To each their own. The he351 is something I always wish I would have tried other than the top chargers i tried, hx35, 35/40, 62/13.
 
I dont have any way to really know whats going to work other than other peoples input and dyno runs. Im hoping going a little smaller on the secondary is enough to make this perform better as a stop and go tow vehicle as well as on the highway. Doesnt have to be super fast.

didnt mean to sound snippy in the last post. my insurance rates are going up because of all the accidents and where I live, its just crazy. gotta do something.
 
Change your stall. My local converter shop doesn't like doing anything under stock, too many complaints at 4-5k altitude.
 
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