Garret Gt4202R
#1
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Garret Gt4202R
Buddy picked up one of these for mega cheap, and I was just curious what kind of set up this could work on, or if anyone has had any experience ext.
Compressor Specs
Wheel Inducer Diameter: 75.8mm
Wheel Exducer Diameter: 102mm
Trim: 55
A/R: .60
Turbine Specs
Wheel Diameter: 82.0mm
Trim: 84
A/R: 1.25 or 1.47
Compressor Specs
Wheel Inducer Diameter: 75.8mm
Wheel Exducer Diameter: 102mm
Trim: 55
A/R: .60
Turbine Specs
Wheel Diameter: 82.0mm
Trim: 84
A/R: 1.25 or 1.47
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It has 2 hotsides with it. I'll look on the exducer idk. It would be on my 5.3 build possibly. But I was going to do a 78/75 on3 deal. For cheap it's a quality turbo though so just seeing if it would vibe with my build possibly
#6
Measure the exducer, I'm curious what it is. What is your altitude & what kind of positive manifold pressure are you planning on running?
I would run it first with the 1.01 & see how the converter responds.
Garret lists that as having a 74.7mm inducer.
Nice turbo, congrats!
I would run it first with the 1.01 & see how the converter responds.
Garret lists that as having a 74.7mm inducer.
Nice turbo, congrats!
Last edited by gtfoxy; 12-25-2015 at 12:48 PM.
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Still kinda new to the science behind picking a turbo. The hotside seems plenty big for a ls-style build. I'm curious about the compressor side? I'm ready to be schooled here...
Also my power goals are above 550whp at first, then bump up to 700ish as I go blowing motors up along the way. Just for reference
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#8
I've looked over that page already. That's why I asked you what kind of manifold pressure you are wanting to run. That, along with a base lb/min engine flow rate is needed to find where "theoretically" in the compressor map you will be.
I can drudge through it with you but on the Garret website go to the tech where it explains reading compressor maps. It will tech you about in/out pressure ratios. Once you figure out the pressure ratios you can map your MAP vs Flow on the map.
I prefer to size turbos so I start at the low side of the high-efficiency island & sweep through it in the mid-range of the RPM band, under high boost, & move into the lower efficiency islands at the top end.
You will find that compressor really wants to be ran in the 2-2.5 pressure ratios around 60-75lb/min, peak. Which is about 15-16/22-23psi on a 5.3 assuming a 30lb/min @ standard atmospheric pressure.
I can drudge through it with you but on the Garret website go to the tech where it explains reading compressor maps. It will tech you about in/out pressure ratios. Once you figure out the pressure ratios you can map your MAP vs Flow on the map.
I prefer to size turbos so I start at the low side of the high-efficiency island & sweep through it in the mid-range of the RPM band, under high boost, & move into the lower efficiency islands at the top end.
You will find that compressor really wants to be ran in the 2-2.5 pressure ratios around 60-75lb/min, peak. Which is about 15-16/22-23psi on a 5.3 assuming a 30lb/min @ standard atmospheric pressure.
Last edited by gtfoxy; 12-25-2015 at 03:15 PM.
#9
Add: on the exhaust side it gets a tad more complex as you need to calculate head flow, which is dynamically based off head balancing & cam timing, to find your available flow rate. Then you calculate enthalpy, based on EGT & flow rate, to pick the best turbine housing based on what kind of response you want to match the compressor side so you achieve a boost pressure based on your calculated flow rate through the engine. Then you can factor in wastegate flow required to bleed excess energy to prevent over/under boosting of the turbo.
At 74% max efficiency, that turbine wheel will work pretty well at using the available energy.
You need to know your atmospheric pressures you will be working with. It impacts compressor & turbine flow(with a free-flowing exhaust) so you know your calculated pressure ratios.
At 74% max efficiency, that turbine wheel will work pretty well at using the available energy.
You need to know your atmospheric pressures you will be working with. It impacts compressor & turbine flow(with a free-flowing exhaust) so you know your calculated pressure ratios.
Last edited by gtfoxy; 12-25-2015 at 03:43 PM.
#14
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How much are you getting it for is the question? If its around the pricing of the 78/75, and its a REAL Garrett BB unit, its stolen LOL or your buddy owes you money.
Its more than enough for your goals btw
Its more than enough for your goals btw