ShortStack

Hey guys. I have some questions for people who have experienced some of these things im about to ask. If anyone can help that would be awesome..

Super 20g... I cant find a straight answer. Im doing the hahn level V kit, should i switch the turbo out? Im not worried about the power it can handle, im worried about its spool and reliability.

The other choices would be the Garrett turbos... either the 2871r or the 3071r..

Im kinda new to turbos...

I understand the 2871 will spool faster, but ive heard you should use the 3071 with a smaller exhaust housing to get a faster spool with higher power. Are there any other differences i should know about?

I am planning on hitting 400hp, and hopefully wanna do more once i can build up my motor. If the 2871 is just good to 400, it would be pointless then id have to get a new turbo to support higher power. the s20g is advertised to hold up to ~450-500hp, but hit full boost by 3500.

That would be fine by me, if that is really the case.

Any input would be awesome. Also, if you provide links, i will not hesitate to do more research myself.

Id like to add some thoughts. Some say the gt3071 would be sluggish, but what if i got it in ball bearing? Im sure that will make a ton of difference. Would also changing the size of the pipe on the exhaust housing (or is there something easier) to make it spool faster?

Has anyone used a D valve?
thanks!
Andy

ShortStack

boo boo kitty bump

06SS ALL DAY

bump for this dood. God Speed btw for the future of you and your car

ShortStack

haha.. thanks man

ShortStack

updated posts...

Anyone used a d-valve in the cobalt?

SilverSurferSS/SC

It all depends on what you want. Coming from the dsm world, the 20g is good for 500hp. It will take till at least 3200-3550rpm to spool up and get full boost. The ball bearing turbos (garrett) are great, but the 20g is indestructable. Ball bearing turbos could require more maintenence. I say stick with the 20g. If later you decide you want more, sell it and get something bigger.

vB00STw

I cant really give you any "techincal" information but all the guys over at VWVortex use the 3071r when they upgrade their stock one. Its always recommended when people ask about turbos and they seem to love it. It must spool pretty quickly because our engines are only 1.8L

ShortStack

3500 i dont think would be a problem... ive just heard of some dsm guys not getting anythign till 4500 - 5000 even sometimes.

So far i think i wanna stick wit the s20g.

vb00st, that is true about your engines.. Man i hate decisions.

SilverSurferSS/SC

I don't think so, besides there are other things to look at that could have affected that. On the Lsj, it will be fine, def. buy 3500-3600. If you want to know, ask Hungry-ccp (I think that's it.) he has the Hahn Level V set-up and could give you a better insight.

06black

if your shooting for the 400mark a 2876 would be clutch for response, but you'll have to run a higher PR to make the power, thus the 3071 comes into play.

however its got a larger rotating mass thus requiring more shaft inertia......soooooooo

its more your call, but i would always favor a DBB CHRA turbo, the transient response and over all response is better. however they are a picky bitch at times(oil supply / drain)

car_guy_09

Go with the 20g, Thats what i run on my talon (hahn s20g, T3 housing, Same as the lsj kit) and i hit full boost (15psi) at about 3200rpm and its a 2.0 so the lsj should be about the same. Plus mitsu turbos are bullet proof which is why hahn used them to begin with

ShortStack

No ****? Awesome, i think that was going to be my plan anyway.

Thanks for the input.. It seems like such a sick turbo.. i cant wait for this puppy.

ANy other pointers you can give me?

Area47

id go with what 06black suggested. i wouldn't do a 20g on it. if you were road racing and limited the car to 15 psi. id do that. however, they tend to **** themselves when pushed hard. we don't have the air flow stock for stock like a dsm head does. so trying to compare those two is irrelevant anyways.

ShortStack

Im only gonna run stock boost (maybe up to 18) untill i get it it tuned somehow.

But i do wanna push it past that... I think i read hungryhip was getting "boost flutter" or something like that.

Everyone seems to go ape pee over the ball bearing ones.. It makes sense why.

Have you heard of a D valve?

Area47

talking about a divertor valve?

it is no picnic at all to tune a turbo car. so a generalization on picking a boost level to run with doesn't come into play till later down the road.

ShortStack

I guess the numbers im putting out are goals...

I really wanna do the tuning myself, but hptuners is just to damn much to justify to my gf... I really need a wideband too.

if the spool is hard to get to s20g up to speed, wouldnt the gt3071 be just as hard? Or will the ball bearing take care of that.

If the ball bearing is just too expensive (some say its acutally a big pita), would the standard 3071 do?

car_guy_09

20g's dont even come alive until about 17-20 psi and have been pushed allot higher with good results.

And it depends on what DSM's your talking about when you mention heads, Mine is a 420a which has allot smaller ports than the 4G63.

ShortStack

The kit comes at 15 psi... i was gonna push it up to about 18 or so till i can tune it.

Were there any problems with oil fittings or such?

car_guy_09

On my car? No but my turbo is in a pretty open area so it will be allot different on a lsj

Area47

im talking a true dsm. 96 and older 4g car.

i hate the 420a engines with a passion. built 4 of them. i reserve that right

car_guy_09

"96 and older 4g car" I take it you have a big background in DSM's? Most people dont know about that

And yea i dont blame you, They aren't exactly easy to get power out of which i why i am selling mine, Race built cammed race head and still struggling for 350whp? No thanks

Area47

i had two of them in the past. worked on countless ones. i don't touch them anymore. so more or less yep. i know about em.

car_guy_09

The true DSM's are good track/weekend cars but not DD's lol

jefferyss

iTrader: (1)

this is by far 1 of the most interesting and useful threads i have read on here in a long time. good job to all of you and the information being shared

subscribed for more info

06black

my 2g has been perfect!

neener-neener bish!