I cant decide which turbo would be the best fit for my lsvtec the .82 a/r gt2871r or the smaller .63... Im hoping to get 375-400hp, a decent amount of tq and quick spool (dont mind losing a couple hundred rpms if it makes up for it in the top end). My setup is the following. 81.5mm B18b1 block w/ stock sleeves, eagle h beam rods, 9.0:1 cp pistons, acl main bearings, balanced crank, stock b16a head, gsr cams, 1000cc injectors, 255lph walbro, neukin mini ram, 44mm tial wastegate, hks ssq bov, full race backdoor intercooler, 2.5" charge piping, 3" bumper dump, skunk2 intake manifold, omni 68mm tb. This is my first complete build so let me know if i should change anything or add anything.

 

Is it safe to say this vehicle will be street driven? If that's the case .63, also did you run a size calculation for your power goal which lead you to this turbo, just curious?

Also, if street driven, why 1000 cc injectors for that power target, are you considering ID's?

Lastly, why only 9:1? I'd start at atleast 10:1 with consideration to tuning, fuel, etc....

 

The .63 will be better for a road car. Also, if you can, increase the compression into the 10:1 range.

 

Yes, street driven. Not a dd but not a track car. I chose the 1000cc injectors cause i can pick them up for a steal. Will running too big of injectors hurt? I always thought they could just be tuned down. & To get to my goal hp, im going to have to run high psi. So i figured the 9:1 pistons would be safest. 10:1 will be just as safe?

 

.82 ar
as the difference in turbo response will not be noticable on that tiny turbo.
the most i've seen on that turbo was 430whp on 84x87 bvtec and it pretty much being maxed out.


I would go 10.1 cr even on 92-93octane you can accomplish 400whp.
if your going ID1000 i'm assuming you will be on e85.

Stock TB is fine. save money and buy a new tps if your old one is questionable.


Skip he FR fmic and just get cxraing talon backdoor intercooler.


~ Core Size: 25" x 8" x 2.75"
~ Overall length: 34"
I can't imagine any shelf backdoor FMIC fitting any better.

 

Oh and i chose the turbo because it spools amazingly fast and makes great power all the way to redline instead of dropping off like the smaller gt28rs.

 

Thank you! Ill go up to 10:1. Im definitely leaning towards the .82. The .63 maxes out at 390 And i dont really wanna push it to its absolute max.

 

.63 is the best size for that turbine wheel.. the .63 t3 housing flows like a .84 t25 housing just to give you an idea. the 82 housing will do nothing but slow down initial response time with no gains.

given that the 2871r uses a 53.9mm turbine wheel going up to a .82 won't benefit you at all, you won't get any more mass flow over the .63 housing.. you'll run out of turbine wheel flow before you hit the flow limit of the turbine housing.

it also worth noting that with the gt2871r wheel combination you won't make much more than 420-430whp due to turbine wheel flow... the size of the wheel is physically limiting power production in this case.

it will probably take roughly 20psi to accomplish your power goals, however, given that you're approaching the mass flow limit of the turbine wheel you might see a slight tapering off of pressure at high rpm/high load but it shouldn't be anything too substantial

 

Looking at the turbo on ATP & it offers a couple options. Would any of these options be necessary or beneficial to my setup?
" -Larger T04E Compressor Housing Upgrade With 4Inch Inlet No Wastegate Actuator
- Larger T04E Compressor Housing Upgrade With 2.75 Inch Inlet No Wastegate Actuator
- Larger T04S Compressor Housing Upgrade With 4" inlet and 2.50" outlet. No Wastegate Actuator
2.385" Inlet 2" Outlet (smallframe T3 used on some factory applications) "

 

Bump

 

Don't bump threads on the first page, this isn't the classifieds..

and no a bigger compressor housing won't help you, like I said it's the turbine wheel that limits this turbo. only way to get around that is get a bigger turbo.

the standard t04b housing is more than adequate for the 71mm compressor wheel. the gt2871r flows roughly 45-46lb/min which doesn't require a larger compressor cover... people are using wheels that flow almost and over 60lb/min in a t04b compressor cover without issue or restriction.

if the wheel called for a larger compressor cover Garrett would have used one.

do you know which 2871r you have? there are 3 different models all with different sized compressor wheel inducers and thus different flow rates.

There's a 48 trim, 52 trim, and a 56 trim.

 

Oh. Sorry lol ive never posted on here. Havent figured out how everything works on here yet. And the one im looking at is a .56 trim.

 

This is correct. Although 420whp is being VERY generous in possible power capability. The 53.9mm turbine wheel reaches less than 20lbs/min even in the larger .82A/R, and you'd be over 25psi or more to reach that point.

The .63A/R is the much better option, and stick to the standard T04B compressor housing. The compressor / exhaust wheel are the same on all three models. The turbine wheel option doesn't start to change until you get to the GT3071R

 

Okay thank you! Ill go with the .63 & 10:1 pistons. Anything else i should add or change to get the most potential out of this setup?

 

Really, the rest is going to be on you. Boost control, the correct internal wastegate (one is 9psi the other is 12psi) and again, purpose of the car helps with the potential of the car.

The turbo is only the First step in making a balanced car. The GT2871R typically comes as a T25 flanged system, you have to find the correct people to make sure that a GT28 T3 flanged turbine housing is being used when you purchase.

I'll be honest, a 44mm wastegate is a bit overkill for this sized turbo in which it could bleed a LOT of boost and negatively affect boost recovery.

 

Good to know. i have a 38mm turbonetics evolution wastegate from my last car, ill use that instead. purpose of the car, take it to the track every once in awhile, but mainly just a fun street car. Stop light to stop light type of power is what i like most.

 

I also agree about not needed a Full-Race intercooler to get what you need , but I honestly have to say the CX Racing is the last company I'd use for an intercooler, be it back door, side door, or standard configuration. I've seen as much as a 9psi drop because of the design of these intercoolers vs. a good Garrett. Hell, even a Mishimoto, Vibrant, or Treadstone would have better efficiency than the CX Racing.

Company and type of Intercooler DO MATTER.. Here's the write up on the differences.
https://honda-tech.com/forums/showth...3074553&page=3

 

I chose the full race because i like the bov on the hot side concept, the back door cuts a lot of piping out of the equation (quicker spool), & lastly because its a whole hell of a lot easier to install on a crx with a traction bar setup lol.

 

any good fabricator can do the same thing with any intercooler...

personally I prefer PWR units, with Garrett and Bell a close 2nd

 

Okie dokie... Not completely correct, but okie dokie.
(Using a backdoor for need of less piping, yes... quicker spool, hehe, no... not when air is being compressed and moved at over 3 times the speed of sound. Won't matter.)

Full-Race is about quick piping, cool drag race setups, more money in their pocket. to match that with a crap intercooler, all the backdoors in the world won't help.

 

I read your writeup. Which intercooler would you recommend if im gonna be pushing 430 max? Preferably something under $400. I checked out a couple of the brands you listed but still left me clueless on which size to run. Just so many options, hard to choose.

 

Sorry im asking so many questions. Just wanna do everything right the first time.

 

Like with everything else, its a balance. Its not just about power "MAX" that you have to worry about in relation to size, but whether or not you're planning to eliminate the front radiator support beam, if you plan to go higher later, etc.

The problem you're going to come into like Charlie Moua will eventually is that size, fin type, and configuration will all take its toll when you go for slightly lower price: The lower you go in price, the higher the probability that you're going to start heat soaking the intercooler, or lose efficiency if you're not willing to cut the bumper support beam, and go to a larger size.

As soon as you start wanting extras like "backdoor" endtanks and side-mounted blow-off valves, the price goes up. Not just in the price of the intercooler core, which may stay reasonable, but now you're getting into fabrication, which is labor... which drives the price up.

So, Honestly, stay simple with the Universal endtank configurations, don't worry about the backdoor stuff, and look again to that intercooler link and read again about the lower cost ones that stay efficient over since these are typically rated at the crankshaft.. (Vibrant, Mishimoto, Treadstone.)

I've PM'd you a suggestion or two.

 

I never got the the pm. Might be cause im still a trial user?

 

Acutally, I didn't have any IAT issues the cxracing FMIC.

I would have kept my FMIC, but it wouldn't work/fit with my FF manifold setup, not because of cooling efficeny. Certerinaly there are "more" efficent cores on the market but cxracing unit was good enough for me at that power level (400-450whp).

OP, currently I have a garrett core with custom entanks.
The reason i went with garrett was because it came highly recommended & other comapnies ETS, treadstone did not have a core in similar size i needed.

GL