2860 to a bigger turbo...2871,3071?

[SNOMAN1174]

I was talking this weekend with some cat guys and they were running 2871 turbos on thier M8 RGT's. I have an 08 D8 Boondocker PGT. It has the 2860 turbo on it. I am extremely happy with it. My sled runs 8.6lbs all day on 100LL at 10k elevation. My questions would be....

1. What advantage or disadvantage would it be to upsize my turbo to a 2871 or 3071?
2. Should I expect more or less lag with the larger turbo?
3. Will I have to adjust the fuel numbers for the larger turbo?
4. Someone mentioned to me this weekend that if I get a low comp head and larger turbo it would be a better set up? Is this true? Or is this guy just talking out his cat litter hole?

Once again I am very happy with my sled but thought I would get some other opinions since I am sure this conversation will take place again this saturday.

 

[tree climber]

obviously a bigger turbo will have more lag. and with a low compression head it takes away some of your bottom end snap too. i would also like to know what there is to gain by running a bigger turbo. maybe lower egts because of better efficiency?

 

[Wheel House Motorsports]

go to the 2871... the 30 might be a hair big for what your doing and get more laggy.

as for bigger being more laggy.. 2871's kick *** at those levels, its almost the perfect turbo, spool is awsome. more power at the same boost levels compared to the 2860.. and 2 strokes love big comressors, its just there thing.

and if you have the updated POO head, then the thing is already so retartedly low compression i wouldnt worry about it.

 

[colbyj]

I've Got an 09 d800 with a 2860 and i just built an iqr conversion with same motor but with a 2871 I've got a power addiction head on the 2871 sled and a 2010 stock head on the dragon. The dragon is at 11 pounds of boost the iqr is at 9. The iqr by far has more power and comes on alot harder but definitly a noticable lag difference. I think the 2860 is definitly better if you are a boondockin type of guy but the 2871 is better for a point and shoot. So it depends alot on your ride style. But ireally like the 2871 power..

 

[SNOMAN1174]

I've Got an 09 d800 with a 2860 and i just built an iqr conversion with same motor but with a 2871 I've got a power addiction head on the 2871 sled and a 2010 stock head on the dragon. The dragon is at 11 pounds of boost the iqr is at 9. The iqr by far has more power and comes on alot harder but definitly a noticable lag difference. I think the 2860 is definitly better if you are a boondockin type of guy but the 2871 is better for a point and shoot. So it depends alot on your ride style. But ireally like the 2871 power..

Sinceyou have the same motor with the 2 different turbos are your fuel numbers different?

 

[brycter]

go to the 2871... the 30 might be a hair big for what your doing and get more laggy.

as for bigger being more laggy.. 2871's kick *** at those levels, its almost the perfect turbo, spool is awsome. more power at the same boost levels compared to the 2860.. and 2 strokes love big comressors, its just there thing.

and if you have the updated POO head, then the thing is already so retartedly low compression i wouldnt worry about it.

go with the 2871. You can run some lower boost number which is better for your motor. also charge temps will be a bit lower giving you better reed life. you shouldn't need to change any numbers. also that turbo works very well in the trees and boondocking. just all around better fit for you sled. 3071 is a bit big unless you are doing some engine work.

 

[knifedge]

----I believe Twisted M8 kits come with the 2876.

--You can check out the thread here

http://www.snowestonline.com/forum/showthread.php?t=269008

 

[SNOMAN1174]

Summer boredom is in full swing. There is a good thread in the ac turbo section about 2860-2871 comparisons. One poster mentioned that he was a fan of larger charge tubes. I think he said he runs a 2.5" tube instead of a 2". The result is better flow and better low end. So stupid question but this would also apply to the polaris turbo as well right? I am contemplating the switch to a 2876, would I benefit from the larger charge tube? Since my sled is in storage I don't even know that this its possible with the boondocker airbox(08 pg d8) so maybe I am asking for nothing. Anyway, the ac turbo thread got me thinking

 

[Wheel House Motorsports]

putting a bigger charge tube/airbox on anything is helpful.. an ac 800 and poo 800 both like better flow..

just going to the larger charge tube with the same small airbox will likely do nothing.. its a whole package deal and a BD doesnt exactly go big on there stuff.

 

[WyoBoy1000]

As you have seen on the ac thread ovs and twisted seem to be the ones more into the bigger turbos, I would call each of them and see what they think when comparing to a 2860, you should get some reasonable info to compare. The poo motor might react different than the ac motor so if you talk to them it might help.

 

[Wheel House Motorsports]

trust me the poo motors like it just as much. i have personally seen what stepping up from even a 2871 does and its amazing.

 

[knifedge]

--It has been discussed that the small turbos cause alot of fuel mapping issues trying to compensate for lack of air, high boost pressures, low volume, etc. Two strokes need to breathe off the bottom to the top end. Basically, anything less than a 2871 Hybrid(flows as good as a 2876 or better) or 2876 for an 800 two stroke is old school.

--The bigger turbos pull harder off the bottom than the M1000 when set up correctly(according to Twisted, OVS, and others)

--If you have a 2871, you can bolt on the parts yourself to make it a Hybrid for less than $500 I believe, you would also need a 2.5 inch charge tube and a 4 inch air filter