Turbine housing question
#1
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Turbine housing question
Okay my new manifold is T3 based so my next turbo will have a T3 turbine housing, but in selecting turbine A/R, I had a question, hoping that someone out there has some input based on experience rather than just theoretical numbers as it is next to impossible to find a turbine map for a GT wheel inside a T3 housing. Info to follow:
I will be using a GT2871 turbo for my next setup, BUT I will be getting the T3 turbine housing option. So considering that the T3 turbine inlet is 136% greater than the T2 inlet (38mm x 49.3mm vs. 44.7mm x 57.2mm from Garrett catalog) and considering that the turbine wheel is the same regardless of selected housing, I was wondering if anyone had any comparisons between the different A/Rs T2 vs T3 housings.
For example, I know that on Brad's ~1.7L his T25 0.64A/R turbine housing spools to ~15psi at 4400rpm based on his MS datalogs (with a boost leak no less) so I was wondering will the 0.48 A/R T3 housing be comparable or too small/restrictive or will the 0.63/0.64 T3 housing be about the same.
FWIW, I'm shooting for ~325-350rwhp and would like the broadest powerband possible (aka early spool, relatively speaking) so if the 0.48A/R T3 housing would still make it to 350 and provide earlier spool, I'd opt for that, but if it's going to choke off the top end then I'd go bigger.
Sure, I could just go with the 0.64A/R, but if the 0.48A/R can get me to my goal AND give me an extra 500+/- rpm of spool, then even better. Granted this may be mentally masturbating over a very small detail, but it's all about selecting the "right" turbo for your goals and the devil is in the details.
I will be using a GT2871 turbo for my next setup, BUT I will be getting the T3 turbine housing option. So considering that the T3 turbine inlet is 136% greater than the T2 inlet (38mm x 49.3mm vs. 44.7mm x 57.2mm from Garrett catalog) and considering that the turbine wheel is the same regardless of selected housing, I was wondering if anyone had any comparisons between the different A/Rs T2 vs T3 housings.
For example, I know that on Brad's ~1.7L his T25 0.64A/R turbine housing spools to ~15psi at 4400rpm based on his MS datalogs (with a boost leak no less) so I was wondering will the 0.48 A/R T3 housing be comparable or too small/restrictive or will the 0.63/0.64 T3 housing be about the same.
FWIW, I'm shooting for ~325-350rwhp and would like the broadest powerband possible (aka early spool, relatively speaking) so if the 0.48A/R T3 housing would still make it to 350 and provide earlier spool, I'd opt for that, but if it's going to choke off the top end then I'd go bigger.
Sure, I could just go with the 0.64A/R, but if the 0.48A/R can get me to my goal AND give me an extra 500+/- rpm of spool, then even better. Granted this may be mentally masturbating over a very small detail, but it's all about selecting the "right" turbo for your goals and the devil is in the details.
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Also forgot to mention, that the 0.48A/R option only comes on the 4-bolt T3 housing whereas the 0.64A/R option comes on both the 4/5 bolt housings. Not a big deal, but the 5-bolt leaves the T3/T4 replacement/upgrade/options open in terms of changing turbos later.
#5
I got your PM, and I don't have any hard data for you. My gut says to go with the larger housing, unless you are using an external wastegate, in which case a 40mm wastegate and the smaller housing could make it viable to make plenty of power while not constricting flow terribly. This is where a larger external wastegate and bring some balance to the equation.
Mark
PS - the 38 mm external wastegate may flow enough as well.
Mark
PS - the 38 mm external wastegate may flow enough as well.
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from what i can determine, the .86 a/r t25 housing is comparable to the .63 a/r t3 housing. both have max efficiency at 21 lb/min. that being assumed, the .63 a/r t25 housing and .48 a/r t/3 housings should be comparable as well at 16 lb/min. doing the math with a 1630cc motor and 8500k, that puts you at 14-15 lb/min of exhaust flow.....
#7
Yeah, I thought about that as well and new housings are ~$150-175 + shipping and then ceramic coating it is another ~$50 or so. Granted that's always an option but it's also an extra expense and effort that I'd prefer not to go thru.
Also forgot to mention, that the 0.48A/R option only comes on the 4-bolt T3 housing whereas the 0.64A/R option comes on both the 4/5 bolt housings. Not a big deal, but the 5-bolt leaves the T3/T4 replacement/upgrade/options open in terms of changing turbos later.
Also forgot to mention, that the 0.48A/R option only comes on the 4-bolt T3 housing whereas the 0.64A/R option comes on both the 4/5 bolt housings. Not a big deal, but the 5-bolt leaves the T3/T4 replacement/upgrade/options open in terms of changing turbos later.
#10
Are you going to track this car? If you are, go with the larger turbine because it should help reduce underhood temps a bit.
I intended to buy a t3s60 with the .63 turbine but the company I bought from was out of the .63 turbines so I had to go with the .48. I plan to "upgrade" to the .63 some day.
I intended to buy a t3s60 with the .63 turbine but the company I bought from was out of the .63 turbines so I had to go with the .48. I plan to "upgrade" to the .63 some day.
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If Tom can run his turbine at max efficiency without choking out, more power to him (figuratively speaking).
I run a .48 myself. My engine produced 13 lb/min of airflow volume out my exhaust at 7000RPM. no reason to rock turbine designed for max 21 lb/min when the .48 is maxed at 16 lb/min.....
it's one of those compromises, while the .63 will probably produce more power per psi, it will spool slower coupled with his tubular manifold and produce a torque curve he doesn't want. If the .48 can satisfy his power goals and reduce the spool 500rpm, then again more power to him.
I run a .48 myself. My engine produced 13 lb/min of airflow volume out my exhaust at 7000RPM. no reason to rock turbine designed for max 21 lb/min when the .48 is maxed at 16 lb/min.....
it's one of those compromises, while the .63 will probably produce more power per psi, it will spool slower coupled with his tubular manifold and produce a torque curve he doesn't want. If the .48 can satisfy his power goals and reduce the spool 500rpm, then again more power to him.
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Thanks for the offers and info. As for the 0.48 A/R only being offered in the 4 bolt T3 housing, that's the only way ATP offers that A/R for the 2871.
If I had a 1.8L, then without hesitation, I'd rock the 0.63/0.64 but considering the 200cc less displacement + longer runner tubular manifold + turbine flow estimates based on other T3 turbos, I think that the 0.48 will be better matched for my goals. From further research, I'm pretty sure a 0.48 A/R T3 turbine housing should flow very similar to the 0.64 A/R T28 turbine housing. So if Brad got 15psi at 4400rpm with the 0.64A/R T28 housing then I should be in a similar ballpark. Sure max power can be fun but so is spool/max boost before 5k rpm, regardless of redline. Granted if I was shooting for 375-400, then I would go larger, but my power goals are more modest.
If I had a 1.8L, then without hesitation, I'd rock the 0.63/0.64 but considering the 200cc less displacement + longer runner tubular manifold + turbine flow estimates based on other T3 turbos, I think that the 0.48 will be better matched for my goals. From further research, I'm pretty sure a 0.48 A/R T3 turbine housing should flow very similar to the 0.64 A/R T28 turbine housing. So if Brad got 15psi at 4400rpm with the 0.64A/R T28 housing then I should be in a similar ballpark. Sure max power can be fun but so is spool/max boost before 5k rpm, regardless of redline. Granted if I was shooting for 375-400, then I would go larger, but my power goals are more modest.
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If you are getting a mani made from scratch, to me it seems easier to get a standard T2 turbine, that way you know what the flow rates are or at least it would be less of a guess. Why go to a T3? If a .48 T3 flows like a .64 T2, they why not use the T2 and simplify things?
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If you are getting a mani made from scratch, to me it seems easier to get a standard T2 turbine, that way you know what the flow rates are or at least it would be less of a guess. Why go to a T3? If a .48 T3 flows like a .64 T2, they why not use the T2 and simplify things?