mrx

Hallo,

here are our plans:

- street driveable car
- sleeved and build b16a engine
- whp goal are something about 450-550 WHP (more is even better)

and here is our problem:
we want to drive the car on hill races where we have many curves so we need that power
with less boost as possible and the turbo must spool as quick as possible because we don't have much time until the next curve where we have to lift of the throttle and so nearly never hit full boost, you understand the problem?! ;-)

We know that we have to go with a lot of compromises because we never could hold all of our plans. But now the question:

What turbo would be the best for such an application? important points are spool up rpm and good efficiency in the used boost area.

I searched allready and found a lot but the most answers are for highway use. So maybe we get some extra informations.
Hope to get some answers.
Thanks
Malte.

Boostfed

Garret GT35R, possibly a smaller one actually GT28RS Disco Potato!

drvfast

What compression are you going to run?

mrx

oh sorry i forgot to mention, we go with a 8.2:1 compression because we also want to be on the save side so that the engine defintiv hold the power.

Greets
Malte.

Boostedcivicsi

i am running the gt35r, good turbo with a quick spool, even on just my 1.6L.

95GSRTT

is it even possible to make more than 450 whp with a quick spool, as in before 5k?

Boostfed

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mrx &raquo;</TD></TR><TR><TD CLASS="quote">oh sorry i forgot to mention, we go with a 8.2:1 compression because we also want to be on the save side so that the engine defintiv hold the power.

Greets
Malte.</TD></TR></TABLE>

No ******* WAAAAY! The lowest on a B16A you want is 9:1 MINIMAL! 8.2 will have no spool up or torque!!!!!!

b16sedan

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boostfed &raquo;</TD></TR><TR><TD CLASS="quote">

No ******* WAAAAY! The lowest on a B16A you want is 9:1 MINIMAL! 8.2 will have no spool up or torque!!!!!! </TD></TR></TABLE>

NO WAAAAAY! I DRIVE 7.8:1 DAILY AND ITS FINE! Feels like it lost, at worst, 10 horsepower going from stock compression, and spool up is so similar it's hard to tell the difference, if there even is a difference.

m R g S r

7.8? What pistons are you using to get it that low? Damn

b16sedan

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by m R g S r &raquo;</TD></TR><TR><TD CLASS="quote">7.8? What pistons are you using to get it that low? Damn</TD></TR></TABLE>

They're a set of JE dished pistons, since the B16A is such a small displacement motor, the flat top pistons that are normally around 10:1 for a B18 become 9:1 pistons for a B16, they are normally sold as turbo pistons. With the dished pistons the compression is about 7.8:1. I bought them for extremely cheap off of a local guy and honestly if I didn't tell you it was under 8:1 compression you would think it is a 9:1 motor, the off boost response is perfectly acceptable.

Boostfed

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b16coupe &raquo;</TD></TR><TR><TD CLASS="quote">

They're a set of JE dished pistons, since the B16A is such a small displacement motor, the flat top pistons that are normally around 10:1 for a B18 become 9:1 pistons for a B16, they are normally sold as turbo pistons. With the dished pistons the compression is about 7.8:1. I bought them for extremely cheap off of a local guy and honestly if I didn't tell you it was under 8:1 compression you would think it is a 9:1 motor, the off boost response is perfectly acceptable.</TD></TR></TABLE>

The lower compression in a B16A is due the 77.4mm stroke, the same pistons in a B18C1 GSR with GSR heard with an 87.2mm stroke will be lower compression than and LS motor with a GSR head with an 89mm stroke!

Boostfed

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b16coupe &raquo;</TD></TR><TR><TD CLASS="quote">

NO WAAAAAY! I DRIVE 7.8:1 DAILY AND ITS FINE! Feels like it lost, at worst, 10 horsepower going from stock compression, and spool up is so similar it's hard to tell the difference, if there even is a difference.</TD></TR></TABLE>

What do you have for a turbo a 12G?

b16sedan

I'm running an SC61 with a TO4S housing, stage 3 exhaust wheel, and a .63 A/R exhaust housing.

Boostfed

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b16coupe &raquo;</TD></TR><TR><TD CLASS="quote">I'm running an SC61 with a TO4S housing, stage 3 exhaust wheel, and a .63 A/R exhaust housing.</TD></TR></TABLE>

HMMMM! Good to hear you are able to sppol it with that low of compression!

c jackson

disco potato cant make that much power can it?

95GSRTT

no, it cant...

SiRkid

what kind of spoolage?

as for the orginal guy.
gt35r or sc61 should be good enough

Boostage

I feel if low compression affects your spool time to an unaceptable level, you probably need head work and a bigger exhaust.. not necessarily higher compression and a smaller turbo.

Boostfed

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by c jackson &raquo;</TD></TR><TR><TD CLASS="quote">disco potato cant make that much power can it? </TD></TR></TABLE>

lol I mentioned Disco Potato just for spool that he was talking about, I forgot about his goal of 450-500whp OOPS! The GT35R would be perfect in my opinion BUT spool will still be good too with mad top end!

Tony the Tiger

For hill races where partial boost and smooth power deilvery is important, you have to get something ball bearing.

Anything non-BB (SC61, etc..) will not meet your demands.

GT35R is the turbo of choice

mrx

Hallo,

many thanks for your informations. i take a look at the compressor maps of both, the gt30r and the gt35r.

first i though about the amount of boost we can truely use on the street because of the time the turbo needs to produce this boost. I think aprox. 14 psi would be that boost that we can use in most cases. i think more boost will take too long to build up and so is only available in a very short rpm range just before redline. or am i wrong? (its only a theoretical guess because i have no experience with that - so if i'am wrong, correct me please)

ok, now we use 14psi boost in most cases in the mid range, then we have a flow of

11 lbs/min @ 4000rpm with 7psi
22 lbs/min @ 6000rpm with 14psi
35 lbs/min @ 8000rpm (now with 20psi of maximum boost)

if i take these values and place it in the compressor maps of both turbos then i'am in the:

72% efficiency range of the gt35r and
72% efficiency from 4000-6000rpm and at 8000rpm i have the full 78%

so should the gt30r a bit better? or is the amount of possible hp even better with the gt35r (bigger turbo) at the same eff.???

Thanks
Malte

Boostfed

GT30R is rated at 500hp and is dual BB, this turbo would suit you nice! And you are right, it may be a better choice.

92SleepyHB

Garrett GT35E or GT35R, the sc61 spool slower but damn when they hit it on....Who??? Mike Jones