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-   -   what to expect (https://www.miataturbo.net/general-miata-chat-9/what-expect-23965/)

madmalc 07-24-2008 06:51 PM

what to expect
 
just bought a gt2876r ball bearing turbo (a propper garrett one for those who saw a previous post of mine)
it goin on my 1.6 with lightened, balanced and knife edged crank carillio rods and low comp weisco's had a little bit of work done on the head 3angled valves titanium springs cams and solid lifters
and bought a hydra nemsis ecu i plan to run about the 13-14psi mark what should i expect power wise a proper tuning company are mapping it and i wont be running a air flow meter

this is the spec of the turbo
Turbine
-Wheel: 53mm w/ 62 trim
-Housing: .64 A/R

Compressor
-Wheel: 76mm w/ 48 trim
-Housing: .70 A/R

i have a huge intercooler and is all hard piped with rolled ends
rc550cc injectors twin feed rail sard fuel pres reg etc etc

disturbedfan121 07-24-2008 06:58 PM

are you looking for a power level? like hp number guesstimation?

madmalc 07-24-2008 07:03 PM

yer power hp just an idea rli as iv seen one at 500bhp on youtube a blue one and that uses the same turbo i think

Fireindc 07-24-2008 07:44 PM

It should make ~300whp at that boost level. <--- guestimation

madmalc 07-24-2008 08:01 PM

ooooo im excited

cardriverx 07-25-2008 12:41 AM

Sounds like the motor can support a lot more than 13 psi, run more =)

samnavy 07-25-2008 10:28 AM

I'd say you're gonna be just shy of 300whp at that boost... especially on a slightly lower compression motor. I'm thinking more like 15-16psi depending on the rest of the setup. It's only a 1.6 after all. Most guys running the bigger turbo's and getting big numbers at low boost are running 1.9's on '99heads or even the VVT heads with Nemesis. A 3" exhaust would be minimum.

You're definitely going to make 300whp...maybe even 350ish in the 20-22psi range.

What rev limit are you going to use?
What manifold/DP are you going to use?
What exact model Sard fuel pressure regulator are you using?

madmalc 07-25-2008 10:44 AM


Originally Posted by samnavy (Post 287740)
What rev limit are you going to use?
What manifold/DP are you going to use?
What exact model Sard fuel pressure regulator are you using?


with the valves, springs and soilid lifters the guy that did the head work seem to think it would happily run round to 9k but ill prob limit it to 7500-7800
the manifold is a complete bespoke top mount that is still been made along with a 3" down pipe and then ill be making the 3"exhaust
not sure which sard reg was removed from a friends time attack car running 500bhp

y8s 07-25-2008 11:26 AM

run more boost. I bet you could close in on 20 psi without problems on a built, low compression motor. You'll need bigger injectors though. the 550s will max out before you get to 300 rwhp.

At 12:1 AFR, 7000 rpm, and just shy of 10 psi on a 2876R, RC550 injectors I'm at 68.5% DC on my car. max recommended duty cycle is usually 80%.

madmalc 07-25-2008 01:21 PM

would 600's be ok

Saml01 07-25-2008 02:22 PM

http://www.rceng.com/technical.aspx

y8s 07-25-2008 02:51 PM

short answer: barely.

long answer: from sam's link...

hp * BSFC / (4 * .80) = inj flow rate in lb/hr

300 * .6 / (4 * .8) = 56.25

56.25 lb/hr = 591 cc/min.

but then you got nothin when you need more power or headroom... get 720s and you can run 350 :D

paNX2K&SE-R 07-25-2008 03:57 PM

Any reason you went with a 2876 over a 2871?

y8s 07-25-2008 04:26 PM

there was no 2871 yet.

madmalc 07-25-2008 05:15 PM

ill order sum 720's then low ipidence or normal

er just fancied the 76r

y8s 07-25-2008 05:58 PM

hydra will run low impedance.

and low impedance is much easier to run lower pulsewidths.

and big injectors need low pulsewidths to idle.

and your spelling is ridonkulous.

cardriverx 07-25-2008 06:04 PM

Get some 760cc low impedence, run 22 psi, rev limit at 8000.

Thats how I would do it with that motor... just try not to break the trans =)

madmalc 07-25-2008 08:16 PM

its like 1 in the mornin my spelling is alowed to be bad lol

my gearbox is a quaife straight cut item :)

18psi 07-25-2008 10:25 PM

it may just be me, but I think its a waste to have a nice and built engine just to run 13psi
turn that sucker up....way up.....18 19 20 are all good numbers:)

samnavy 07-25-2008 10:31 PM

^Because if you build a motor to handle 400whp and only ever turn the boost up to make 300whp and then run 1000rpm less than what the valvetrain could handle... it will last forever.

It makes sense to me to set your power goal, "overbuild" the motor to achieve it, then have piece of mind that a boost spike or over-rev won't require a tow.


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