GT2871r Good enough for DD

[Y.O. Cop]

I recently bought a Speed 6 with engine troubles. I have bought a new block(actually used but have been inspected and honed). I am in the process of collecting all forged internals for the block. Now I have the following mods:
-CorkSport SRI/TBI
-Cobb AP
-AutoTech HPFP
-CorkSport FMIC
-M2 DP
-CorkSport CBE
-various mounts/suspension upgrades.

My question is, is a GT2871r a good turbo to use if I only want to achieve around 350-380 awhp or should I spend the few extra bucks to get the GTX3071 ? I have searched all over the forums but I haven't found any useful info about the GT2871. Can someone explain the difference. It seems both can produce about the same crank hp(according to streetunit.com). Any info regarding this would be helpful or any suggestions for additional mods would be great as well. Thanks

[atvfreek]

The 2871 is an excellent turbo for DD and with e85 or meth you can get 350-380awhp

[Y.O. Cop]

Can I achieve that on 93 octane? The closest place thay pump E85 is 2.5 hours away. Meth injection seems viable. I will research that. Has any alternate race fuel been tested outside of E85 that you know of? I believe there's a Q15? Or something being sold at the track by my house

[SarcasticOne]

Look into bnr s3, it's effectively a 2871, but cheaper
Also, don't buy from street unit

Sent from my Nexus 5 using Tapatalk

[Y.O. Cop]

I will. Does that use the same flanges as ATP turbos? Sorry for all these quetions, I haven't found a thread describing turbo options without going BT. Also folks keep saying don't buy from streetunit. What's wrong with streetunit? Asking out of curiosity

[SarcasticOne]

Originally Posted by Y.O. Cop I will. Does that use the same flanges as ATP turbos? Sorry for all these quetions, I haven't found a thread describing turbo options without going BT. Also folks keep saying don't buy from streetunit. What's wrong with streetunit? Asking out of curiosity

a BNR S3 is almost a straight bolt up... can re-use stock sized TIP etc
think you just need a new coolant line, or something...

street unit saga:
http://www.mazdaspeedforum.org/forum/foru...design-139503/

[ckMS3]

350whp will be hard to achieve on 93 only. You'll need meth for 350whp+. It is a great dd turbo though.

[Y.O. Cop]

Sweet, I appreciate the help guys. I know I asked a lot of questions but I wantto try and stay away from BT simply due to reliability of my new motor. Again thank you all and I'm alwaus open to suggestions and and questions about my build

[Mortose]

Don't buy from street unit because cullin eats penis's. Search the forum and you will find all the details as to why he, street unit, and sure are all knob gobblers.

Edit: proof linked above.

And I'm running the gtx2867r, and it's a fantastic DD turbo, and the 2871 is right next to it.

[ckMS3]

Bnr is a great cost effective turbo. On low boost and minor bolt ons I made the numbers in my sig wish a splash of e85.

[Y.O. Cop]

Wow. I had no idea streetunit was that bad lol. I'm definitely looking into BNR S3. Van I order the coolant line from them? Are you all running IWG's or EWG?

[Lex]

If you're only going to use 93 and want a bit more top end the GTX3071 will allow you more hp than a 2871 as the turbo will generate less heat/be more efficient and keep knock at bay a little better. A GTX39017 will have an easier time going over 350 than the BNR S3 and 2871 but the BNR is a great price and very easy to bolt on.

You will give up a little bit in terms of response but with the MS6 being AWD and heavier it should spool the snail to 20psi well below 3500 RPM.

[Roddiy]

Id vote for a BNR or GTX2867 if you want a DD with very quick spool but looking to stay under 400s on 93oct

[Y.O. Cop]

Would water meth help reduce knock?

[Mortose]

Yes, due to the cooling and the added fuel.

And I'm running IWG on mine. Fortunately, I don't suffer from boost creep, thanks to an awesome tune from @Lex;

[Y.O. Cop]

That'll most likely be the set up I will go with so I can get my car on the road faster. I gotta make space in my garage for my actual project haha. If I can find a station thay pumps e85 then I may sale my turbo set up for something bigger.

[Lex]

Originally Posted by Y.O. Cop That'll most likely be the set up I will go with so I can get my car on the road faster. I gotta make space in my garage for my actual project haha. If I can find a station thay pumps e85 then I may sale my turbo set up for something bigger.

A smaller turbo will need higher octane to hit the same numbers as a larger one.

Originally Posted by Mortose Yes, due to the cooling and the added fuel. And I'm running IWG on mine. Fortunately, I don't suffer from boost creep, thanks to an awesome tune from @Lex;

We need to finish that off since you have your clutch sorted now.

[JgamB]

Originally Posted by Lex A smaller turbo will need higher octane to hit the same numbers as a larger one. We need to finish that off since you have your clutch sorted now.

@Lex; you've made me curious if the speed6 experiences OEM clutch slip more readily due to added drive train resistance. Have you seen that trend in cars making ~340 AWHP vs ~360FWHP?

[speed3 britz]

The BNR S3 Is a great option for DD as many agree, I have mine waiting to be installed once once out of storage. Essentially it is a drop-in turbo since re-using the stock hotside, with exception of coolant line like stated above, which is an added few bucks. Everything else is bolt up and stock connections

[Lex]

Yes a car with more traction at the wheels will be harder on the clutch. Also it is often not the peak amount of torque but rather how quickly the torque ramps up. On smaller turbos they spool and ramp very quickly leading to more slip.