GEN2 LS

iTrader: (3)

I have a high compression b16 block (11:9.1) in my car now, considering pulling it out and replacing it with a semi-stock b18c1 block (nippon pistons 9:3.1 stock rods). I'm aware b16's are a tad bit on the laggy side, would I notice any BIG difference on how the car responds on the street from just switching shortblocks? The b16 is on E85 at the moment and I would be going back to pump gas if I put the GSR block in the car. I would like full boost around 4k. With the current setup the b16 is hitting full boost a hair after 5k, with a Precision 6031 .63 hotside, 59mm compressor wheel. Don't care about big power numbers i'd be content with 350whp, just a simple street car I just prefer more "USABLE" power for street use/power under the curve so to speak.

92frostwhtdb2

Simple answer, yes. You can wait for other elaborated replies if it makes you feel better.

GEN2 LS

iTrader: (3)

lol, thanks! although if you took the time to post you might as well have elaborated a bit, all my turbo setups have been b16's, so I dunno what torque and full boost before 5k is:p

92frostwhtdb2

I could've but I'm on my phone just browsing the forums, its too much off a mission to write a technical reply so I instead answered exactly what you asked lol...the compression ratio in this case is irrelevant below 9:1 maybe ..I doubt you'll be disappointed in anyway

GEN2 LS

iTrader: (3)

yeah i'm sure going from a 81x77 to a 81.5x87.2 regardless of CR should make a noticeable difference just wanted some feedback/elaborated answers. Thanks though, yeah that's a mission replying from a phone lol.

nealnanoHX

Personally I would just stick with the B16 built block, if it is sleeved and this is coming for a 1.8L all the way guy. If not then go for the GSR block, sell the B16 block and get some rods for it. The GSR block has more over the B16 than just being larger. Peak boost will be minimal compared to the 2 blocks the B16 is higher compression so it will be more responsive but the B18 is slightly larger and will make more low end tq and has a longer stoke. The B18 may spool up the turbo a few hundered rpms sooner. If you only are shooting for around 350whp a change in turbos will get you the lower peak boost and still get you the 350whp with room.

crvtectim

Man, if you really want to improve your powerband, consider a big ***, quality final drive like mfactory. What transmission are you running?

GEN2 LS

iTrader: (3)

sorry I didn't clarify, the b16 is a stock motor other than CTR pistons.

GEN2 LS

iTrader: (3)

a cable J1 b16 trans, not sure i'd be to happy to run a 4.7 or even a 4.9 FD set on boost, and I doubt they even make them for the older cable transmissions.

Spawne32

iTrader: (3)

1.6 liters are torqueless wonders because of the 81x77 rod/stroke

crvtectim

Ah ****, nevermind, your gears are short enough with the 4.4 FD.

FlewByU352

But dem revs! More displacement is better for spooling turbos as well which is why the 1.8L is a better choice. More air physically filling the cylinders, more exhaust to spool the turbo quicker. It is a win/win situation.

nealnanoHX

Then yeah for sure swap to the GSR block, sell the B16 and get some rods for the GSR to beef it up a little more. The bigger GSR motor will make more power and has some tq. The B18B1 is even better, it has a slightly longer stroke than the GSR but is a bit weaker.

Bseriescivic5

Personally, I dont think your going to see a real significant difference.... The most significant advantage I see here is that you will have a larger knock threshold by switching to the GSR block.... (are you going to continue to use E85 with the GSR?); Even if you decide to go to pump gas with the GSR, its still nice to have soom comfort room with the lowered compression. The tune has to be spot on for High compression turbo engines, but Im sure you already know this.

Bottom line, expect a ~500rpm sooner spool with the larger block, and a larger knock threshold as well, assuming you are sticking with e85, although I would imagine it would still be plenty safe on pump 93

crvtectim

I'm thinkin' a new turbo will be best. Plenty of choices that will spool faster and hit 350.

nealnanoHX

The GSR will also be better when out of boost, the B16 is a snail down low. Keeping the GSR a stock 10:1 will make is peepy when not in boost and spool up the turbo nicely with the high compression and longer stroke. I know the B16 the OP has is 11.9:1 and the GSR he is looking at is 9.3:1. At 9.3:1 it will still be decent down low, 10:1 will be funner though.

GEN2 LS

iTrader: (3)

if I went with the GSR block I would go back to pump gas, only reason I am using E85 is because of the CR of the b16 motor, my only gripe about E85 is the availability in my area isn't the greatest so I find my self going out of my way alot to get gas. I even carry two 5 gallons jugs in the hatch for reserve tanks in case I get caught way out from the nearest E85 station. If all I will see is prob a 500 rpm sooner spool I don't think it will be worth all the work. I'm prob gonna just go get the car retuned on a higher boost pressure, maybe once the turbo is in it's efficiency range it might help the spool and wake up. 9psi isn't hardly anything on this turbo, I think once I turn it up to at least 13psi then I should be happy.

nealnanoHX

You can run the B16 on 93 or even 91 pump gas it all in the tune. You really just need to decide if you want a more potential motor for more peak power or just better turbo response. If you are unhappy with the laggy turbo you have then a here are a few to look at that will do 350-425hp and spool around 3500-4000rpms. This is when I want boost for my DD so these are all turbos I look at and considered.
Garrett T3T4 50 trim
Garrett T3T4 57 trim AR stg 3
Garrett T3T4 60 trim
Garrett GT3255B
All will meat your needs and are $800 or less. These are all pretty common turbos for a B series street car.

Tony the Tiger

350 WHP and spool around 4K RPM? It has to be a 1.8L

GEN2 LS

iTrader: (3)

a smaller turbo would solve my problem, but my current turbo is maybe a year old with maybe 5,000 miles on it, if that.

92frostwhtdb2

you should really consider the want 1.8 swap.The main reason your looking to go this route is to have a better powerband, not having to wait as long for the power to come on correct?(you only want 350whp). Stock for stock driving a b16 vs b18c is no comparison.Don't just look at a number in terms of spool time remember with the increased displacement your adding torque and more of it lower in the rpm range versus the 1.6 that combined with forced induction is going to increase your all around output compared to the b16. If you see were im coming from dont look at it like just, me spooled at x amount of rpm is only what im looking for, you wouldnt have the need for an increased time in spool if your midrange and off boost powerband were more to your liking.

nealnanoHX

^ There is a reason I went LS Vtec for a turbo build.

H22AFerio

X2

GEN2 LS

iTrader: (3)

I see exactly where you are coming from.