Downsizing turbo

Reboosted

New member
I"m thinking of downsizing my turbo. The ty came with a pte51. It has an ultimate chip with stock everything else (injectors,stall,manifolds,cam,...). The thing can't build any boost off the line and is a dog. Its a daily driver and would rather downsize the turbo than put in a stall. I dont believe there is anything wrong with the turbo, just too big for the combo. Its fun on the freeway, but I'd like more oomph off the line. I'm considering the pte44 but noticed it still has the same stall rating on rpm site. I was looking for this one because it should bolt right up. I don't have a bunch of money for this and would prefer to reuse the (4 bolt) downpipe and other stuff already on the truck. Would the 44 spool any better than the 51? Are there any other turbos to consider? This is an oil only turbo and would like to keep it that way.
 

sy#2716

SyTy 4 Life
Re: Downsizing turbo

Instead of getting a new turbo just get the conveter restalled or a new converter.
 

TYTILIDIE

METH HEAD
Re: Downsizing turbo

I agree with the above but if you are totally bent on getting a smaller turbo, Ild say go with Wallers 57 20g. You can get you a stock DP cheap. I know you could buy Abes 20g with stock DP for about 4-500. Let me know.
 

Jimmy

Banned
Re: Downsizing turbo

sy#2716 said:
Instead of getting a new turbo just get the conveter restalled or a new converter.
That turbo is a great one for a stock motor. Instead of going backwards,you should restall the convertor like everyone said.
 

Reboosted

New member
Re: Downsizing turbo

I think it would be cheaper/easier to get a smaller turbo. I can resale the turbo I have now to partially offset the cost of the new one. I can do a turbo in a weekend, not a converter. I dont want to screw with a good working trans. I can't afford to pay someone to do it. I don't want to put the trans through any extra stress. I don't want to sound like I'm trying to race everyone at every redlight. I rarely boost launch the thing. I have never had a car with higher than stock converter, so I may be overreacting to the idea of putting one in. If I didnt have to change the downpipe I would have the original turbo rebuilt and put it back in.
 

sharkbait

New member
Re: Downsizing turbo

what state you in? i'd trade you for my stock turbo/downpipe with the waterlines plus some cash. let me know.
 

NecroWolf

lost marbles member
Re: Downsizing turbo

i happen to have a set of bare poncho heads for sale and looking for a turbo
 

Reboosted

New member
Re: Downsizing turbo

Yeah I was poking at ya. Where in texas are you? Houstonish? Just found out i'm getting a 20% raise! I'll check with you in 3 weeks about the heads, cash.
 

JSM

Active member
Re: Downsizing turbo

I bet the spool could be improved with a proper tune for your truck. As could a lot of other things. No matter the turbo I would suggest a tailored tune for your truck.
 

NecroWolf

lost marbles member
Re: Downsizing turbo

Reboosted said:
Yeah I was poking at ya. Where in texas are you? Houstonish? Just found out i'm getting a 20% raise! I'll check with you in 3 weeks about the heads, cash.


i'm north of austin in killeen. figured you might be. i doubt they're going any where. i need to work with you, uncle sam's pay check blows. sad part is i got offon a tangent on my engine rebuild and some how this has come to include an in dash dvd player, a kicker l7 15 and other non speed goodies
 

dgoodhue

BuSTeD 4.3
Re: Downsizing turbo

I think a PTE44 should spool up faster. It has the same sized compressor wheel with a smaller exhuast wheel. A better tune would help spool up. Atleast when they were availble for SyTy, the though was the PTE44 was good for the stock stall converter and the PTE51 was borderline. If its really sluggish, my guess is you have out of tune issue going on as wel.
 

Raist103

Engine Killer, iPhone Killer, Lawnmower Killer
Re: Downsizing turbo

if all else fails i have a waller 57 and stock dp and a small amount of cash i could do in trade for your setup.
 

TYTILIDIE

METH HEAD
Re: Downsizing turbo

TwinTurboV8Ty said:
I bet the spool could be improved with a proper tune for your truck. As could a lot of other things. No matter the turbo I would suggest a tailored tune for your truck.

X2, I had this problem and it just needed a little bit more fuel to get it going.
 

turbodig

Active member
Re: Downsizing turbo

dgoodhue said:
I think a PTE44 should spool up faster. It has the same sized compressor wheel with a smaller exhuast wheel. A better tune would help spool up. Atleast when they were availble for SyTy, the though was the PTE44 was good for the stock stall converter and the PTE51 was borderline. If its really sluggish, my guess is you have out of tune issue going on as wel.

Got a local with a Ty with the tighter stock converter and a TE-44. While it doesn't spool up like a stocker, it can still break the tires loose on a boost launch.

In a perfect world, it should have a ~ 2600 converter, but it's ok without.

I don't see a 51 being that much worse. My guess is that there's something else wrong with your truck.
 

Tooky

Serious about performance
Re: Downsizing turbo

Hey Reboosted, I think you're on the right track for sure!! Downsizing the turbo makes perfect sense, depending on a few things.

In my experience, the reality is a bigger turbo won't make your stock motor ANY faster, unless you also run high octane fuel and raise the boost (with a chip). So it comes down to a question - do you plan on running high octane fuel? Turning it up at the track with race gas? Modifying it down the road?

If you do, then the PT51 is a great turbo for that purpose. I even got mine to run 11.79 @ 114 with a PT51, stock motor, and stock torque converter. (I was able to tune it to get the tires to spin off the line: check the videos and see a complete list of my old build on my website: www.PowerTunePlus.com)

Before I tuned mine, my PT51 with the stock converter, was a total dog as well and I also couldn't build any boost at the line, like you.

Putting a high stall in a stock transmission is a terrible idea IMO. What typically happens is it throws the entire stock transmission calibration out the window, resulting in WOT shiftpoints at too high an RPM (where the stock heads/cam are totally choked). It also can produce too-early part throttle shifts, ruining driveability. You are wise to be suspicious about putting a converter in your stock trans.

If you are tight on money but want to race down the road - you could do a stock turbo (or stock-style mild upgrade) for now and keep the PT51/downpipe on the shelf for later. The stock style turbos won't work with the PTE downpipe though, if that's what you have (I didnt know what you meant by "4 bolt downpipe").
 

Reboosted

New member
Re: Downsizing turbo

I do have a stock turbo and downpipe, but the turbo would have to be rebuilt. If its salvageable. I can pull the shaft out about half an inch. I dont care to race the truck but would like it to be more driveable for the street, which is why I was shying away from the higher stall converter. The 51 and its downpipe were on the truck when I got it. Now one thing I have noticed while poking around the stock turbo, there is a widget with an electrical connector and a couple vacuum connections on it. I'm guessing this is for the computer to cut boost when it senses knock? Its on the stock turbo, in my store room, not the turbo on the truck. Is the ultimate (radar style) programmable like the code 59 style or will it have to come out? I do have an adjustable fpr and there is a second o2 bung thats plugged right now, so I have a place to add a wideband. I have a scantool, but I'll have to see how much information it shows. I was just using it for diagnosing cel/abs codes, but it does show some live data (rpm-boost-coolant temp, not sure about kr, hafta see when I get home).
 
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