Was a decent day i guess, i was rather disapointed with my numbers though....




Mustang Dyno;
227rwhp - 5900rpm
235rwtq - 3600rpm

@ 12psi

It will only hold 6psi after 5500rpm, i have absolutely no idea why....


Oh, and to top things off, i roasted my clutch and it's starting to slip like crazy....




P.S. How do my AFR's look?...

 

If thats on the stock turbo, you should be DAMN proud. On a Dynojet (read: an ACCURATE dyno, Mustang dyno's read HELLA low) you'd be at around 250rwhp and 265ft lb..


Wtf? Something must be wrong with the dyno. Theres no way you can be making more torque than horsepower.

AFR's look a *tad* lean to me..:-O



Edit: Our turbos are old, and undersized. They tend to, unless in new-condition, not hold anything over 8psi at redline.

 

He is making more torque than HP because he isnt holding boost.

And mustang Dynos report more realistic numbers than dynojets do, and they all you to pull 1/4 mile sims if you like.

In any case you made pretty good numbers there, dont be disappointed.


BC

 

Uh, he made the "high" torque around 3200RPM - LONG before his boost drops off, and right around the time when most stock turbos hit full boost. Your assumption is wrong...

 

so what would be your assumption?


BC

 

Probably the dyno was reading wrong, or something O.o


I don't know of ANY turbo rotaries making more torque than horsepower, expect by maybe 1 or 2 ft lbs. Never 8 ftlbs..

Tons of things could come into play, but I would think it was the dyno reading wrong. I mean, this torque is at 3000RPM!! Rotaries don't make torque in low RPM!

 

i've had the torque kick in that low on multiple dyno sessions, and this time i gained 45rwtq more then last and only 2hp more....

you said the AFR's look a little, lean?...

 

i have to admit that is weird

 

See, my assumption is that he peaked boost around the time of peak torque, then started loosing boost thereafter, seeing only 6 psi by 5500 rpms. This would explain the high torque down low, with the high hp being lower than tq. obviously if the turbo wasnt loosing boost the HP and tq numbres would look more classic on the graph.


No where did he say that he held 12 psi until 5500. He just said that at 5500 he was at 6 psi.


BC

 

do you guys think my AFR's look lean or...?

i thought around the 3500rpm-3900rpm it got a little lean so i added a tick more fuel in that range....

seam ok?...

 

What turbo are you running?

Warning out the *** talk - Doesn't the engine need the most ignition advance and I would assume fuel to prevent detonation at peak torque?

James

 

Oh idea on the boost drop off....

When you first start the dyno run your WG is staying shut and building the right boost....however as the engine starts flowing more exhaust....it is actually forcing the WG flapper open before it should be...and it is letting the exhaust bypass.

I would trying putting an extra spring on the WG arm to help hold it shut longer.

I guess you could trouble shoot this by wiring the WG shut...and CARFULLY doing a few runs to see how the boost behaves.

There are pictures of WG actuator rods with springs on them... search for BNR turbos.

James

 

i'm not sure what you mean, is my engine at risk or no?...

oh, and i'm running a stock S5 turbo with ported wastegate....

 

Meh, I still think your turbo might just be getting worn out. I only know of 2 or 3 people who can hold full boost to redline, and they might just be lucky. The sock turbo is wayyy small, not meant to be boosted high, in the high RPM..

But yeah, It "looks" a little lean at certain points. Especially on that big spike near the end.


I'd go to a different dyno, just for comparison sake.

 

that thing at the end is kinda weird, oh, and the turbo is off another jspec motor that had 42,000km's....

 

i should also note that when it's kolder out it spikes at about 14.3psi for a split second that i dont even notice but holds about 13.2-13.5psi throughout until it drops off in higher revvs....

i only know it spikes at 14.3psi because it records the highest boost hit....

do things seam alright?, AFR's and boost?...

 

* Bump *

 

What type of boost controller do you have?
I think a ball & spring type would help you hold more boost in the upper rpm's.

That is if you are using a bleed type currently.

 

never mind I see you have an EBC

 

nice
i had kinda same setup so check out mine
https://www.rx7club.com/time-slips-dyno-128/my-dyno-chart-stock-jdm-s5-556866/
boost drop off is normal... for stock turbo

 

just me but your fuel ratios seem rich. you had more power when your fuel ratios leaned out. look at the graph I would stay close to 12.0:1.

 

Where was the dyno reading the A/F's? If at the tail pipe dual or single exit?


I don't think your A/F's are to bad. Try to richen it a little at the transition for the secondaries and a little at that spike at around 5600.

 

wastegate ported too big? when it opens the actuator isn't strong enough to close the wastegate