BB or not to BB

[MaxBoost]

Im gonna be getting a new turbo and need advice from someone. Im looking at AGP's LR2 BB with a Mitsubishi exhaust housing and internal gate or AGP's complete T3/T4 external gate setup with the works.

This:
http://www.agpturbo.com/kitonmotor.jpg


I just want some opinions on the differences in spool up, and what would work the best for my setup.

660's, 190lph
MAFT, AFC, Pocketlogger
Large Sidemount
Still strong stock block and head(ouch! Maybe LR1 instead of LR2?)

Am I dreamin?

 

[larryd]

First off the turbos are L2R and L1R, not LR2 and LR1.

Next I hope you dont expect to run any of these turbos on a large diemount ic as it will heatsoak fast.

Finally what trim T3/T4 and what are your goals for the car?

 

[MaxBoost]

I don't know too much about trim ratings. Pretty sure they have to do with the size of the turbine housing. Is this right? I was thinkin 50trim, but I kinda like like the L1R. The full garrett setup is about the same price as L1R My intercooler is a Dejon Tool large sidemount and I cant afford both the turbo and a FMIC.

The goals:

-To get solidly in the 12 second range on pump gas with a Fwd
-Full boost no later than 4000 rpm
-Tunable with an AFC, MAF Translator, pocketlogger

I really need to get to both a dyno and the track to see where I stand.

 

[JayHass]

BB ='s quicker spool (Generally about 500rpm or equal to one turbine A/R size down in response when speaking Garrett speak.) more efficient, greater side load strength.

Downside? More $

 

[hostile]

So if you got the .48 AR 50 trim you could spool even with a .63 ar 50 trim BB turbo?

Also is there an l2r full garret turbo? And what is the cost on the kit with ball bearing?

 

[MaxBoost]

Ok, but doesnt having the Custom Manifold, External Gate, Bigge O2, etc. close that gap a little? Or am I still lookin at 500rmp difference approximate.

 

[JayHass]

Originally posted by hostile
So if you got the .48 AR 50 trim you could spool even with a .63 ar 50 trim BB turbo?

Also is there an l2r full garret turbo? And what is the cost on the kit with ball bearing?

I can't speak for .48's. IMO they are too small for hybrid applications and give a weird unrealistic boost curve.

A .82 with all else being the same aside from BB will spool like a .63 for the most part. I'm speaking from first hand information with two identical cars with the same turbo's one BB one not. They spool identical but I made 80whp more by going to a .82 housing with no other changes.

Maxboost BB is in addition to whatever you can do.

 

[MaxBoost]

Somebody give me a website so I can get used to all these numbers and what they describe

 

[TurboAWD92GSX]

www.agpturbo.com

 

[TurboAWD92GSX]

also your going to need a front mout. a large sidemount will work but will not produce very high hp numbers.

 

[Unreal]

Local guy has a .48 50 trim and loves it. Full boost by 3600, awesome response, and ran 11s 1st time out with it, with a blown HG and slipping factory clutch. Doesn't get much better than that.

 

[allwheelTSI]

Originally posted by hostile
So if you got the .48 AR 50 trim you could spool even with a .63 ar 50 trim BB turbo?

Also is there an l2r full garret turbo? And what is the cost on the kit with ball bearing?

yes there is, you can see it at www.agpturbo.com it starts at $2100.

 

[Violater101]

In a FWD car, I personally wouldn't go BB on a FWD. Even though you are FWD, there are plenty of proven turbo's on the market that can reach your goals and would be cheaper on the pocketbook. Like they said, BB will only increase your spoolup time which in turn equals wheel spin that much sooner. On a side note, they do sound cool when you turn the car off

 

[KRAZYKOREAN]

Dood go BB all the way...

 

[larryd]

Originally posted by Violater101
In a FWD car, I personally wouldn't go BB on a FWD. Even though you are FWD, there are plenty of proven turbo's on the market that can reach your goals and would be cheaper on the pocketbook. Like they said, BB will only increase your spoolup time which in turn equals wheel spin that much sooner. On a side note, they do sound cool when you turn the car off

Agreed, being FWD you want lag.. lag is your friend. 50trim in a .63AR housing would spool up full boost around 3800 and is good to put you into the 12s solidly on FWD assuming you can drive.

 

[JayHass]

More than just lag you want a smooth boost curve. You can get GREAT transient response and efficiency with a BB turbo but create a "smooth" boost curve with a larger A/R housing.

For instance a .48 goes like this SPIKE, hold, drop off.

An .63 is kinda like mild spike, hold steady to redline.

An .82 is like ssssllowwwbbbbBBBBBBOOOOOOSTT, HANG ON till redline. It comes on much smoother and has wicked top end. The BB center section brings back the civility of the turbo.

Those are my experience with BB and non BB Garrett T3-T4's with various housings.

 

[candela]

Agreed, being FWD you want lag.. lag is your friend. 50trim in a .63AR housing would spool up full boost around 3800 and is good to put you into the 12s solidly on FWD assuming you can drive.

awww come on Larry... Lag is nobodies friend. Solid 12's will be pretty hard without some massive traction up front anyhow. Who serisouly wants a laggy turbo cause they are FWD but wants to go really fast (et wise) at the same time? If you want to go fast dont get a laggier turbo just cause your FWD. THats my advice, you can always make up for wheel spin on the street with your foot, all these new boost controllers coming out or even just think about how much gas is and you wont want to get on it =)
My favorite thing is shift response. Even with a bad driver who completely lets off the gas in between shifts and doesnt keep the turbo spooled Ive noticed the BB turbo's will come to life much quicker than a conventional in between shifts. Once its spinning a good bit it just takes a tap of the gas to get full boost back!

 

[Unreal]

Friend in NM ran 12.7 on a br20g, stock head, stock cams, stock intake, stock motor 98 gst. Full exhaust, fuel system, IRC fmic, and br20g. Any of the above turbos should be easy 12 second turbos, even on a fwd.

 

[MaxBoost]

Thanks for all the advice. Keep it comin.

 

[candela]

friend did a 12.8 on a big16g, 3" back 550/afc/logger/255lph and like 22psi on nitto nt555r's

 

[doug]

I've been hearing a bit lately about the questionable reliability of the BB turbos-- what's the deal with that?

And do any of the above suggestions change if you have an A/T car, since we kinda have built-in lag to begin with?

 

[MaxBoost]

Well my car feels realy strong and even more now that I have a logger for my afc/maft. It might be able dip below 13.00. The only problem is the that I get mad wheel hop/torque steer. Is AGP the best option for a BB turbocharger? The L1R looks like can make some good power.

 

[larryd]

Originally posted by candela


awww come on Larry... Lag is nobodies friend. Solid 12's will be pretty hard without some massive traction up front anyhow. Who serisouly wants a laggy turbo cause they are FWD but wants to go really fast (et wise) at the same time? If you want to go fast dont get a laggier turbo just cause your FWD. THats my advice, you can always make up for wheel spin on the street with your foot, all these new boost controllers coming out or even just think about how much gas is and you wont want to get on it =)
My favorite thing is shift response. Even with a bad driver who completely lets off the gas in between shifts and doesnt keep the turbo spooled Ive noticed the BB turbo's will come to life much quicker than a conventional in between shifts. Once its spinning a good bit it just takes a tap of the gas to get full boost back!

I have a heavy foot. It would not matter if I was running 5lbs or 50lbs of boost I would always manage to find a way to spin tires through 1st and 2nd

 

[JayHass]

Originally posted by doug
I've been hearing a bit lately about the questionable reliability of the BB turbos-- what's the deal with that?

And do any of the above suggestions change if you have an A/T car, since we kinda have built-in lag to begin with?

I don't know who you have been listening too but that's the whole PURPOSE of a BB turbo. They can take MUCH higher side loads. The GT series turbo's were developed for the multi-million dollar race teams first and now Garrett tossed us some crumbs.

Once its spinning a good bit it just takes a tap of the gas to get full boost back!

Exactly! I loved my BB for this very thing. Excellent transient response. The turbo is always "on" and ready to go.

 

[BlitzMR2]

Originally posted by JayHass
More than just lag you want a smooth boost curve. You can get GREAT transient response and efficiency with a BB turbo but create a "smooth" boost curve with a larger A/R housing.

For instance a .48 goes like this SPIKE, hold, drop off.

An .63 is kinda like mild spike, hold steady to redline.

An .82 is like ssssllowwwbbbbBBBBBBOOOOOOSTT, HANG ON till redline. It comes on much smoother and has wicked top end. The BB center section brings back the civility of the turbo.

Those are my experience with BB and non BB Garrett T3-T4's with various housings.

With what kind of wheels? I have a (T3/T4) .48 with a Stage 5 wheel, 50 trim T04E, ITS Dual BB. I drove a non BB version and it spooled quickly, hit slightly less hard than my 20G and pulled solid to redline, no spiking and then dropping off. My BB version will be on Tuesday, so I'll let you know how it feels, but the inherent beauty of hybrid turbos is that you can change your mind; if it feels like butt, I can swap out to a 63 or even 82 housing. Sweet.