gt2871r build , asking codyace, idahotuner, kentuckey slider....all the gurus

[gixxerbob]

I would like to start this thread by saying that I only want to hear from people who have pushed the gt2871r to its highest power capabilities, I only say this because there is too much riff raff on some threads and people giving opinions with no research or experience behind these statements. If you have never owned a gt2871r then you probably shouldn’t post but if you know your turbo talk please add to the thread

DO NOT (yea I used caps haha) don’t ask if I have ever driven a 2600lb car with 450whp, or say that I don’t need that much hp or any other stupid comments. Including “you should focus on spool or the entire dyno graph not just the peak” although that is not a stupid statement I realize this already but want to focus on a whp goal. Please give me some info behind your statement (don’t just say “no”….say “no, because the ….”.)

To those of you who are qualified to give advice i would like your insight on a few things i am unsure about, but feel free to comment on things that i have or plan to buy listed above.

I have followed almost every gt2871r build thread on nico, f/a, zilvia… it is obvious that this turbo has pushed 420+ hp with the .64 a/r turbine housing but I want to push it to 450, possibly upgrading to the .86 but not if the .64 is thought to handle 450.

I drift occasionally when I can get a group of 240 guys together but I really plan to bring the car to VIR and autocross days when I can this upcoming summer but 99% of the time the car will be a street monster off of red lights and making more expensive and newer cars look bad. haha My set-up These are the parts I already haves14 sr20det zenkiGreddy 1pc new style intake manifoldGreddy m-spec Koyo radiator F-A-L fans Samco hoses Nismo thermostat Nismo fpr Z32 fuel filter Z32 ignitor chip Power enterprise oil filter Motul 5w40 Spec stage 3 clutch Spec street flywheel Valve guide seals Megan down pipe Megan test pipe HKS hi power exhaust Innovate wideband B&M fuel press gauge megan boost/oil press/oil temp/water temp gauges megan manifold dei header wrap z32 transmission and lower harness shimmed z32 diff walbro 255 greddy rocker arm stoppers oem oil pump oem water pump ngk iridium #7 oem timing chain tensioner nismo radiator cap still have to buy power fc d-jetro with map sensor kit and boost controller mazworx transmission adapter aluminum drive shaft apexi head gasket Arp head studs Gasket set Brian crower springs Extrude hone turbine housing Mobil 1 transmission oil 3qts Turbo timer cp pistons/eagle rods/apr rod bolts acl main/rod bearings arp main studs bore, hone, tank, linebore, deckhead, deck block, polish, balance, mic crank, cut flywheel freddy oil pan oil filter relocator and cooler catch can turbo timer synapse bov greddy turbo elbow

I was thinking of going with the jgy gt2871r kit with 72lb inj and top feed rail but unsure of the injectors, who makes a 60lb mototron adapter kit for my greddy manifold any more since I could not find a HASS kit. Or what other options would I have for a higher impedance, lower lb injector that would fit my greddy manifold even if I use 4bar fuel pressure instead of 3bar and work towards a 450whp goal

i plan to boost the hell out of the motor, i was wondering where the maximum efficency of the gt2871r lies as far as psi and whp. ( .68 and .86) (going with the 56 comp trim)

9:1 or 8.5:1 since I will be doing high psi with a reasonable flow I have been planning/ researching/collecting parts for 6 months now. Recently a friend of mine has chosen to build a redtop gt3076 but I want to show everyone that more research behind a gt2871r build can be more efficient than a high dollar top-mount setup. (i really want to show him up and make him look bad haha)

what cams, I know codyace like the s3 cams but im going to shoot a little higher whp, I was going to buy s3 cams if I could find them used or brian crower 264's if I go new because the s3's are so much...would you recommend s4 or c1's hks bc toda…? . Thanks for reading and any valuable input that you post -rob

[two40splease]

Long post lol but i guess it explains what you want... If anything minimum go with a .86 ar gt2871r and everything mod supporting for 450hp. I didn't read through your post thoroughly but if your doing more VIR racing where you'll be higher rpm's most the time= you def should consider topmount gt30. With any gt 2871 turbo you'll be pushing it to the edge of its efficiency range and putting considerably more strain on your setup to reach the powergoal than if you were to go with a gt30.

edit: JWT s4 cams at a minimum I have s3's for the street and it sounds like you want more aggressive than me for cams.

autocross you'll want quick boost response gt2871 would be better for that.

you said 99% street 450 to the wheels so go with . -

.86 gt2871rs4 camsgreddy intake 72#injectors 60's will work but more people go with and tune for msd'sjwt ecu or enthalpy, I like nistune you'll get a more precise tune in the endpush 18#'suse Codyaces idea for stock exhaust manifold

that should get you started
Modified by two40splease at 1:19 PM 2/4/2009

[supreamS14]

megan manifold = crack megan manifold+dei header wrap = CRACK CRACK CRACK

PLEASE DON'T!

Greddy, tomei or moroso oil pan. I would trust a knock-off intake manifold before a knock-off oil pan.

Sounds like it's gonna be a fun build! Good luck!

[gixxerbob]

megan manifold = crack megan manifold+dei header wrap = CRACK CRACK CRACK

yea, just like broadfield had his manifold crack..but they are only 130$ each....i might have a oem manifold extruded and swained like codyace when i have the turbine housing extruded, but i am sure i would bo a full-rac twinscroll gt30 before i buy a nice bottom mount manifold.

if your doing more VIR racing where you'll be higher rpm's most the time= you def should consider topmount gt30. With any gt 2871 turbo you'll be pushing it to the edge of its efficiency range and putting considerably more strain on your setup to reach the powergoal than if you were to go with a gt30. Modified by two40splease at 1:19 PM 2/4/2009

i'll probably turn down the boost quite a bit if i bring it to a track but that would be 2-4 days a year (i meant 1% of the time on a track and 99% on street)

thanks for both of your replies, keep the good stuff comming

[jr_ss]

If you want to extract every last hp out of the motor, I would send the head to mazworx and have them CNC the chamber. It gets rid of the quench areas, elminating the chance for detonation and increasing flow into and out of the head... A port and polish would also benefit you...

I've talked with Mark at Mazworx, he said to make horsepower with our little engines, you really need to rev the piss out of them. With that said, I'd do HKS/Tomei solid pivots and cams. Good luck on the build

[gixxerbob]

CNC the chamber. A port and polish would also benefit you...

I've talked with Mark at Mazworx, he said to make horsepower with our little engines, you really need to rev the piss out of them. With that said, I'd do HKS/Tomei solid pivots and cams. Good luck on the build

does anyone know how much hp would be gained from a port&polished head? i would imagine 10-15whp, good idea

as far as revving the hell out of the motor i dont know how much of a gain i would get from reving to 9000 rpm as opposed to the 8k i plan to rev to (ras, bc springs/retainers, 264), if any gain at all. also i would have to consider the bang for the buck factor, i really dont plan to sink tons of cash into the head if it wouldnt be a great benefit. Between the cams, bc springs/retainers,ras, deck, cut seats, seals, posible p&p...then all the cash for a solid lifter assy and all the other parts that go into reving to 9k i dont think money could be spent other places for better results. if i was running a larger turbo at a less than peak efficency i could see the 9k redline but i think i will hit peak well before 7krpm and the torque curve will begin to drop around 6k rpm.

thanks for the ideas, any thoughts on the whp a p&p would do

[freakyjason]

as far as revving the hell out of the motor i dont know how much of a gain i would get from reving to 9000 rpm as opposed to the 8k i plan to rev to (ras, bc springs/retainers, 264), if any gain at all.

With the GT2871r, revving to 9000 rpm's will be a little out of it's efficiency range and it will be blowing lots of hot air. At this point, gains would be minimal. With the right cam, i suppose you could slightly nullify these effects but we are still talking about minimal gains. Also, i would definitely go with the 72lb injector setup as you will probably be at around 80% duty cycle at 450hp with your setup which is pretty comfortable.

[gixxerbob]

With the GT2871r, revving to 9000 rpm's will be a little out of it's efficiency range and it will be blowing lots of hot air.

yea i thought so much

thanks for confirming my suspicions

[jr_ss]

Gixxer... If you're going to get a valve job on the head anyways, you'd def benefit from the CNC'd combustion chambers. It's only $210 and will allow the head to flow alot more, here's a link http://www.mazworx.com/index.p...=2752. I wasn't saying 9k rpm rev range on a DD but to each their own. I think a different exhaust housing will help with the flow of the 2871r as well. ATPturbo sells a very nice unit that I plan on running on my car, although I'm going BTM 3071R I believe, link here http://www.atpturbo.com/Mercha...e=GTH. It comes only in a .72 ar, but I think it's a nice blend between spool and top-end power.

As far as 9k rpms out of the efficiency range of the 2871r .64 then yes, but a larger housing and it should flow quite well up there. I'm alittle biased though because I only plan to rev to 7.5-8k depending on where I continue to make power. If power falls off at 7.8k then I'll set the rev limiter a few hundred rpms higher.

[gixxerbob]

Gixxer... If you're going to get a valve job on the head anyways, you'd def benefit from the CNC'd combustion chambers. It's only $210 and will allow the head to flow alot more

yea, i have decided in the past 2 days that i will get the head ported and polished since all the power is made in the head anyways.i will also get a na s14 throttle body (60mm) or the n15 throttle body and adapter (70mm) i am aslo considering getting the greddy intake manifold ported or gasket matched ports at the least. anfd still on the fence about the extruded oem exh manifold , but certain about the extruded turbine housing.

thanks for the link

[gixxerbob]

does anyone know the most psi a 2871r can push?

[freakyjason]

I've heard some people say that 25 psi is safe on that turbo. However, I consistently hear that 21-23 psi is a pretty safe range.

[rc1honda]

I have a similar build going on right now. s13 redtop 2871r .86 HKS 264in and exhaust Stock intake and exhuast manifolds msd 50lb injectors ( im thinking of getting bigger ones) BC valve springs and ret. Power FC L-jetro Well im having the the head built right now full p&p 3 angle valve and complete assembly. I wondering what kinda power im going to put down so i will check back in on this thread. And i wanna kinda keep the stock manifolds cuz im told it will help with the lower end power. The car is going to scream anyway. Any of your results and thouhgts would be cool but im not going for peak power. I just want good strong reliable power.

[gixxerbob]

i have seen a couple of guys push 555cc injectors to high 300's and one guy pushed them to damn near 400 but they were running at over 90%

[homeslicej2]

Look forward to following another build. The only real input I can make, since I still have a stock hairdryer..uh..T25, is that the Greddy M-spec FMIC will not support 450whp. Greddy, and most sites that sell it, state that 300whp is about the limit for that core. oh, and definitely not a knock-off oil pan.

[gixxerbob]

yea, since it is bar and plate it will not give me the performance gains of a tube/fin intercooler but my good personal friend is pushing 500 with a knockoff bar/plate intercooler, i just assume there is some psi drop and not as great cooling as a tube/fin. i plan to set up my intercooler like a v-mount anyways so hopefully it will stay cooler than the average. i will see how it works. i might sell it and get a tube/fin but i got this ine off of my parts car and have zero $ invested into the intercooler.

[idahotuner]

hey i havent read through this whole thing. but i read the whole OP.

i personaly think with race gas, built bottem end. 25-28 psi on the .64version would get you near 450 to the wheels. 264 cams and a good tune. upping the compression seems like it would help.

the whole wanting to show up your budy is slightly unrealistice. i am changing my build over from a gt2871 to a gt3076 ts or possible a gt35 twinscrol. but the gt3076 is good up to 525hp area.

i am going to be doing some research on upping the compression with forged pistons and then running a bigger turbo to see what the gains can be had.

as far as intercoolers work. i think there is to much sppeculation. seems like the more surface area the better cooling but saying that the m spec or ls greddy intercoolers wont support it are bogus.

i am running a greddy ls which is the replacement for the m spec. and it has treated me awesome. sure when i upgrade to a bigger topmount setup i kinda wanta bigger one. but at lower boost this one should work fine.

i got to get some home work done now. i hope this has help you

[jr_ss]

Idaho, some benefits you'll see out of uping the base comp ratio will be; better off boost response and making more power at lower levels.

Take for instance, you're running 15psi andmaking 300rwhp at 8.5:1. You put it to 9:1 and run 12psi and still make that 300rwhp. Longer turbo life, lower egt's yadda yadda.

My build has a 9.1:1 comp, which I'll be pushing a 3071r with this exhaust housing, http://www.atpturbo.com/Mercha...e=GTH

[idahotuner]

Idaho, some benefits you'll see out of uping the base comp ratio will be; better off boost response and making more power at lower levels.

Take for instance, you're running 15psi andmaking 300rwhp at 8.5:1. You put it to 9:1 and run 12psi and still make that 300rwhp. Longer turbo life, lower egt's yadda yadda.

My build has a 9.1:1 comp, which I'll be pushing a 3071r with this exhaust housing, http://www.atpturbo.com/Mercha...e=GTH

nice. i think i am going to go for some crazy midrange power. 3500-7000 possible 8 but using a TS gt3076r

so 9.1 to 1 can be crazy. but i am going to call mazworx and see if i cna get 8 to1 in a .5mm over bore.

that will help spool up but give me less chance at nocking.of course a methanol injection will help out

[jr_ss]

I'm going for crazy mid range with a decent top-end. I don't need nor want to rev to the moon. Once it stops making power, I'll set the rpm limiter at or slightly after that mark, whether that is 7k or 8k or somewhere inbetween.

I wouldn't go 8:1 with the SR. If anything stick with the 8.5:1 and get a thicker head gasket. No sense in getting custom pistons made. Making the head gasket thicker will lower your comp as well. There are formula's to do this but you need alot of information from your engine. 8:1 ratio, won't help with spool up, you want to raise the comp to flow more air when you're in negative boost. You can advance timing to help with spool, but you'll lose top end power.

Higher octane or water/meth injection would be something I'd look into if I were you. I want to be able to run 93, but have a race gas tune that I can load. I'll be using a Haltech E8 w/ MAP conversion.

[gixxerbob]

well, im getting 1500 on my tax return and have to sell my other s14 shell and a couple thousand in parts that i wont be using anymore, i will then start a new thread for the actual build starting off with my crazy suspension build and having the block built at the machine shop. i have to get quotes on the p&p and other extensive head work, the bottom end is going to cost approx $700 to machine

[idahotuner]

I'm going for crazy mid range with a decent top-end. I don't need nor want to rev to the moon. Once it stops making power, I'll set the rpm limiter at or slightly after that mark, whether that is 7k or 8k or somewhere inbetween.

I wouldn't go 8:1 with the SR. If anything stick with the 8.5:1 and get a thicker head gasket. No sense in getting custom pistons made. Making the head gasket thicker will lower your comp as well. There are formula's to do this but you need alot of information from your engine. 8:1 ratio, won't help with spool up, you want to raise the comp to flow more air when you're in negative boost. You can advance timing to help with spool, but you'll lose top end power.

Higher octane or water/meth injection would be something I'd look into if I were you. I want to be able to run 93, but have a race gas tune that I can load. I'll be using a Haltech E8 w/ MAP conversion.

yeah i have had to change some stuff now. my block needs resleeved, so i can do a nice big over bore and keep the stock compression. but then focus on air flow for mid range power.

aem to tune it. and i will do a map for methanol or water injection.timeing is something i wantot keep close to stock as possible.