64/71 vs 66/73

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feller

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How do these two turbos compare?

From the research I've done on CF it seems that the 66s are mostly hype and people say they hit hard because they have a lot of lag?

I would figure a turbo that has a bigger compressor/turbine/housing would support more HP especially since they are made by the same manufacturer but is this not the case?

I am ordering a turbo soon & a spool flange and wondering which of the two I should choose. Any help would be much appreciated
 
I have always been very impressed with the 64/71 turbos over the years. They have always been my choice.
 
feller said:
How do these two turbos compare?

From the research I've done on CF it seems that the 66s are mostly hype and people say they hit hard because they have a lot of lag?

I would figure a turbo that has a bigger compressor/turbine/housing would support more HP especially since they are made by the same manufacturer but is this not the case?

I am ordering a turbo soon & a spool flange and wondering which of the two I should choose. Any help would be much appreciated
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If you're going to run it with a spool flange get a 467 from T$. MadMikeIsMad runs that setup and I love it.
 
the 64mm is actually a 64.5mm the 64.5mm and 66mm both have the same sized base of the wheel aka exducer (91.3mm IIRC)
there are differences , but often overstated.

many aftermarket turbos have upgrades that are not in the box units. Instead of a spool valve why not do a cam or porting?
 
I run a 64/71/14. It's a great charger for DDing and the hitting the track on weekends. The 66/73 flows a few more lbs on the compressor and turbine but in my opinion, the only single I'd upgrade to would be the 67.7 FMW. Flows much much more than the 66.
 
I dont want to incease my timing anymore being that I'm already at 20*

The reason I want a 66 instead of a 467 is because I dont want to deal with surging when the valve opens up under 2/3rds throttle. Also dont want to spend the extra 1k on the turbo alone. Also there should be a pretty noticeable increase in lag between a 66 and a 467.7.

JKIDD the reason I am planning on the spool valve is because it's bolt on, MUCH cheaper and makes a bigger difference in spool than porting or a cam do. Keep in mind this is a street driven truck that gets driven offroad in sand dunes very fast frequently. The suspension is first priority and turbo lag is not something I can have very much of being that I need close to stock spool manor navigating terrain at these speeds offroad.

Also have been looking at the 472 but I'm not sure that would spool very well even with a spool valve and I read about someone having issues when the spool valve opened up with this turbo.

Keep in mind this isnt a truck that lives on the dragstrip, very rarely will it see full throttle for more than a few seconds
 
TheBigNasty said:
Since you already know everything, why don't you just do it then?
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At least he's done some homework.

OP, You're leaving out the AR of the turbine housing..? I ran a 66-74-.70AR (12cm) and that was one of my favorite single turbos. Although I haven't run any of the 64-71 versions I had better spool up compared to a friends truck with a super B special.
 
Maybe a larger A/R on the s467 than the typical 0.90, maybe go with the 1.10 with the spool valve.
 
BigNasty I dont know everything, I'm looking for people that have first hand experience with these 2 chargers to hear their input before I order. I'm not sure I would trust a salesman 100% for info if they didnt offer all of my options.

Young Guns I intentionally left out the AR ratios because I'm curious if the .83 would choke up on top or if the .91 even with a spool valve would still be laggy on bottum. I know a .83 + a spool valve would spool really fast but I dont want to have crazy drive pressure /egt problems
 
Ghostman would a 67/83/1.1 AR +a spool valve spool close to stock? Thats a pretty big jump in turbines going from a 66/73 to a 67/83.

Is the 467 available with a smaller turbine or would it defeat the purpose? Possibly create surging issues? Or is there no difference in lag?

I know I'm asking alot but I'm still learning about these spools valves
 
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My 467 FMW doesn't have any more lag than my box 366 did. I don't have a fair comparison tho, because I changed the cam and went to a higher stall converter....

Sent from my paperweight
 
If the 67 wasn't an extra 600 dollars I would definitely go that route but honestly its a little out of my budget. That's why I look at the 66. Just want to know if people avoid it or not for any reason.

Sent from my SCH-I535 using Tapatalk 4
 
I feel like all the suggestions that have been made were contradicted by the OP?

To be honest, if your willing to spend the money on a spool valve, why not do the non gated .83 T4 housing and spend the extra money you'd save not buying a $500 gated T3 housing, and not buy a spool valve and just run an external waste gate with the .83 T4 housing? You'll have good spool and twice the waste gating capabilities of an internally gated T3 housing. AND still be money ahead.
 
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Murphy if I were to do an external waste gate I would have to either buy a different manifold or run a spacer with a port for an external Watergate then I'd actually have to buy the external waste gate.

Sent from my SCH-I535 using Tapatalk 4
 
And even then its not guaranteed a 66/73/.83 would spool fast enough on its own, whereas a spool valve + either the .83 or .91 would spool fast enough

Sent from my SCH-I535 using Tapatalk 4
 
murphy41 said:
I feel like all the suggestions that have been made were contradicted by the OP?

To be honest, if your willing to spend the money on a spool valve, why not do the non gated .83 T4 housing and spend the extra money you'd save not buying a $500 gated T3 housing, and not buy a spool valve and just run an external waste gate with the .83 T4 housing? You'll have good spool and twice the waste gating capabilities of an internally gated T3 housing. AND still be money ahead.
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This is actually the best sounding idea. We always have a give and take when talking spool threshold, $, setup, etc. if you are wanting 600HP or more with a single you will need to just get use to lag(compared to twins or smaller turbos and less power). You might consider a 63/68/.91 T-4 and dial the power back to 500HP. This would spool better, DD better, and still make good power. Cheap too.

Headcase just went from twins to a s464(same turbine as 467), he could tell you his experience with lag.
 
I've had a 64/71 14, 66/73. 91 and a 72/83. 91. The 64/71 was the best, most fun turbo I had for my setup at the time. Quick spool with a nice hit. The 66 was too laggy and smoky for the hit it produced. When I got a tighter converter it helped it a whole bunch but still meh over 50 mph. Now the 72?... Whole different animal. Not much laggier than the 66 but a nice amount of power.

Edit for AR sizes
Sent from my SAMSUNG-SGH-I717 using Tapatalk 2
 
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