I'm going to be running a gt4294 with an external wastegate as a single. Question is what a/r best suits me? They offer 1.15/1.28/1.44 I don't tow much but would like to be able to.
Gt4294 which a/r????
- Thread starter dmaxbowtie
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If you're running an external gate get the smallest AR available. I think 1.01 like mentioned above is it.
I am purchasing a modified model from forced performance which is why the a/r's differ. I believe they may even use a different turbine wheel all together.
Well my power goal is 800whp(ish) on fuel only and the 4294 seemed to be promising with "quick" spool up while still reaching my hp goals. I want a street able setup not a strictly drag truck.
You looking journal bearing, or just too lazy to type the full name? Or maybe forced performance just uses the same cartridge and that's it?
I've been researching the GTX 4294, but so far I've only found a few cummins 6.7 guys and supposedly there's a shop with a duramax GTX4294 tow truck but I can't remember which one off the top of my head.
Everyone was running the 1.01 A/R and said the spool up was very linear and controllable compared to the s400s, but I've never experienced it myself.
If you're looking at a journal bearing though all that's sort of out the window and you may be money ahead with an S467/87/.9
I've been researching the GTX 4294, but so far I've only found a few cummins 6.7 guys and supposedly there's a shop with a duramax GTX4294 tow truck but I can't remember which one off the top of my head.
Everyone was running the 1.01 A/R and said the spool up was very linear and controllable compared to the s400s, but I've never experienced it myself.
If you're looking at a journal bearing though all that's sort of out the window and you may be money ahead with an S467/87/.9
I've driven a gt4294R on a mildly built Lbz (dmaxfireman)'s old truck. It had the 1.15 housing and spooled very quick in my opinion. He made over 700hp with his own tuning, using 30% over injector tips from George Alexander. I've heard a lot of people on this forum say bad things about this charger, but not from experience. I liked it on his truck.:thumb:
Considering Garrett/honeywell's recent move to ax the 4094, I'd be willing to bet we will see more of the 4294r line up.
I have thought this turbo would be a sweet single for some time now in a 1.01A/R, and every time I mention the damn thing I get told to just run the 4202 cuz the maps are darn near identical albeit favoring the 4202, the 4202 has greater potential bla bla...all true.
Still doesn't mean the 4294 can't make good power #'s and be a good street and tow charger, and if you got a good deal on it what can it really hurt to try, with tuning constantly evolving someone should be able to get this charger to work well for you
Go for it and let us know :thumb:
I have thought this turbo would be a sweet single for some time now in a 1.01A/R, and every time I mention the damn thing I get told to just run the 4202 cuz the maps are darn near identical albeit favoring the 4202, the 4202 has greater potential bla bla...all true.
Still doesn't mean the 4294 can't make good power #'s and be a good street and tow charger, and if you got a good deal on it what can it really hurt to try, with tuning constantly evolving someone should be able to get this charger to work well for you
Go for it and let us know :thumb:
I wish: it were that simple.....money grew on trees......and LBZ's came with forged pistons and rods....
:rofl:
I have a question relating to a/r ratios. I need an expert to answer the question and didn't want to start a new thread.
Why don't people run a tight a/r ratio on the turbine (say 1.01 or .90) and then just put two large gates over it, so once it reaches max boost it will bypass it, and then feed the primary charger if it has twins. Just something I've been thinking about that I feel is worth thinking about.
Why don't people run a tight a/r ratio on the turbine (say 1.01 or .90) and then just put two large gates over it, so once it reaches max boost it will bypass it, and then feed the primary charger if it has twins. Just something I've been thinking about that I feel is worth thinking about.
Do a search here for wastegate setup or "gate setup" or "drive pressure" or anything related. There has been dozens of conversations about the use of gates on the duramax and how-to's and why-not's. Also, you will find some good tech info on how a gate works and it's limitations.
After speaking with Robert at forced performance, I'm going with their slightly larger gt4299 journal bearing. I'm going to try the 1.15 a/r and see how it does. The gt4294 they sell claims 90lb/min and they convinced me that I may fall short of my 800(ish) whp goal. The turbo I'm going with has their own billet 72mm compressor wheel and I believe their own comp cover with the regular garrett turbine wheel rated at 103 lbs/minute. Prices were also the same.. Any input on my decision is always appreciated. I spoke with dan@ppe about the gtx4294 and it would be an awesome turbo!! The price at the moment is what stops me from buying one.
I will, I hope It behaves well on the street. I think the tighter a/r is going to keep it streetable.
the garrett turbines are naturally restrictive for their size, I wouldn't worry about it honestly. It's a pretty small turbo for a built motor truck with head work, injectors and dual fuelers.
We'll depending on the cost why not go with the S467.7? May tow better with smaller and lighter comp wheel and still has a peak flow rated at 94lbs/min.
Kory Willis has one on a stock block LML with bolt ons if you wanted to ask about it.
It also seems to be the king of journal bearing turbos on the 6.7 cummins too for what that's worth.
Kory Willis has one on a stock block LML with bolt ons if you wanted to ask about it.
It also seems to be the king of journal bearing turbos on the 6.7 cummins too for what that's worth.