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-   -   Max Power Standard Cams dyno problems help needed (https://www.miataturbo.net/engine-performance-56/max-power-standard-cams-dyno-problems-help-needed-103021/)

Turbo2004 05-23-2020 05:34 AM

Max Power Standard Cams dyno problems help needed
 
Quick rundown on my setup in my 2004 msm
Full built motor forged wiescos aftermarket rods arp bolts etc
Ported head with upgrade fm valve springs.
VVT flat top manifold with larger throttle body < match ported to head
Log style manifold < match ported to head
3071r internal gated full 3 inch exhaust no cat 1 muffler
4 inch intake of turbo with large k&n filter
Usual size inter cooler piping and decent size inter cooler up front.
1000cc injectors and upgraded full fuel system
LS3 style coils

Pump 93 fuel
Seems like we hit a bottle neck on dyno car does not want to make anymore power no matter what boost or timing we put into it
21 psi 22deg of timing
24psi 18deg of timing car gains like 3-4hp at the back wheels ?

Besides the standard cams i cant think of what else could be causing it any idea ?
Car pulls strong to 7200rpm red line

psyber_0ptix 05-23-2020 08:49 AM

What intercooler piping size are you working with?

technicalninja 05-23-2020 10:01 AM

What power level are you at now?
What brand of turbo?
21-24 psi on a 3071r should be a shitload of power.
I'm using one of these (a real Garret) on a 91 MR2 turbo. At that boost level I'll be on E85 and making 450+ at rear wheels.
It would waste my completely forged bottom end on pump gas.
At 15 psi I'll be on 93 making 325 at rear wheels, which will be more than enough for street use.
Way more than a Mazda transmission can hold (even a six speed).
What is your turbine inlet pressure? (in exhaust manifold before the turbo)
A log style manifold may be far above its total flow capacity with that turbo at those boost pressures.
Size of everything in the system matters at these flow levels.

Turbo2004 05-23-2020 10:46 AM

psyber_optix i will have to check size but outlet of turbo is same size as piping maybe 2 inch or 2 1/4 inch
Other side of intercooler to throttle body is 2.5 inches i think

Technicalninja
Genuine garrett gt3071r But the t2 flange rear one but with the largest .86 rear housing. Not using the smaller .64

andyfloyd 05-23-2020 12:52 PM

Show us a Dyno chart and a log.

LeoNA 05-23-2020 02:17 PM

Max power and at what afr?

Turbo2004 05-23-2020 07:14 PM

Not a usa dyno so already lower didnt get copy of dyno sheet i was there whole time car was on dyno
was around 270 whp on 21 psi
24 psi was like 274whp
AFR was around 11.8 on boost on 21psi
Around 11.8 on 24 psi

Dyno area was around 65f room temperature so not hot and ecu was not hitting any kind of iat over temp etc timing reductions etc

18psi 05-23-2020 09:40 PM


Not a usa dyno so already lower
:laugh:

sixshooter 05-23-2020 10:10 PM


Originally Posted by 18psi (Post 1571791)
:laugh:

+1

Turbo2004 05-23-2020 10:41 PM

hehehehehe
better watch it il get banned soon :)

andyfloyd 05-23-2020 11:01 PM


Originally Posted by Turbo2004 (Post 1571783)
Not a usa dyno so already lower didnt get copy of dyno sheet i was there whole time car was on dyno
was around 270 whp on 21 psi
24 psi was like 274whp
AFR was around 11.8 on boost on 21psi
Around 11.8 on 24 psi

Dyno area was around 65f room temperature so not hot and ecu was not hitting any kind of iat over temp etc timing reductions etc

Yea for your boost level you are like 100 hp less than what it should be making. There has to be a reason why, my engine with a FM log manifold and GT2560 @17psi made 296whp/302ftlb I'm only running 18* timing at redline. You said you were running like 20* of timing at 21psi and it made 270... Something is amiss.

Have you checked the timing gears to make sure they are timed correctly? It's hard to explain where that power is going, is your clutch slipping, wheelspin on the Dyno? It just doesn't make sense

curly 05-23-2020 11:06 PM

Do you at least have a log of the dyno pull?

Turbo2004 05-24-2020 01:18 AM

Have checked timing and everything lines up as it should
No wheel spin on dyno as strapped car well
Dont have any logs

Turbo2004 05-24-2020 04:48 AM

So had a look at car today and thought something wasnt right. Got another timing light and base timing supposed to be 10 deg when locked in ecu
Flashing around 6 deg. Looks like old timing light i used has seen better days

GR124 05-25-2020 02:04 AM

Would the Log Manifold choke it? Cause too much engine back pressure? Is this the sort of mani you are running
https://www.enginebasics.com/Advance...omanifold3.jpg

Turbo2004 05-25-2020 09:48 AM

Yeah similar to your picture gr124

shuiend 05-25-2020 10:08 AM


Originally Posted by GR124 (Post 1571861)
Would the Log Manifold choke it? Cause too much engine back pressure? Is this the sort of mani you are running
https://www.enginebasics.com/Advance...omanifold3.jpg

I don't think so. I have customers with my log manifolds hitting north of 300whp with $200 chinachargers. They are in the 20-25psi range.

Turbo2004 05-25-2020 10:24 AM

Yeah i didnt think the log manifold would be holding me back that much
Thanks shuiend
At what point is it worth changing to say a 264 cam size or so on setup like mine and what kid of WHP gain would i expect ?

Ted75zcar 05-25-2020 11:11 AM

You need to state your goals. It is much more likely that a different turbo choice is the right way to go. A 3071 w 0.86 A/R will be a poor performer on a miata for all except a very select few applications.

SpartanSV 05-25-2020 11:16 AM


Originally Posted by Turbo2004 (Post 1571879)
At what point is it worth changing to say a 264 cam size or so on setup like mine

Probably sometime after you figure out what's wrong with your current setup. Has mechanical timing been verified?


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