Thread: Had the 3.9 RRC dyno'd today

Originally Posted by PhilipA

It cost AHEM $450 Gulp., but I guess if IF( that's a BIG IF) I gain 2l per 100Km, then over $300 will be recouped over 10KKm.
Don't tell SWMBO.
Regard sPhilip A

Excellent result, hope the gains prove worthwhile

As for the $300.00 saving.... It wont happen...

You spent it on the Dyno Tune chasing the $300.00 saving

Sounds very good Phillip, its amazing the difference a tune can make to a car performance. Whats sort of dyno does Spiro run?

I had my rangine on the dyno at united fuel injection here in perth. I was fortunate enough to be able to tune it myself. I didnt push the total hp figure up but the difference in mid range torque we managed to squeeze was very good.

I wont hijack your thread with details of my car though

What are you cruise and WOT afr's? How far did you go with timing advance?

Is 68kw's fairly normal for a 3.9? my old wolf 3.9 made 83kw (if i recall correctly) but this was on a 2 wheel dyno so that probably pushed the figure up.
The 4.6ltr made 138.5kw peak and around 350nm's but this was on a different brand (a bosch 4 wheel dyno) to the normal dyno dynamics so its not really apples for apples.

Any chance you could post up your graph just for interests sake?

cheers
Luke

Originally Posted by Tombie2

....As for the $300.00 saving.... It wont happen...

You spent it on the Dyno Tune chasing the $300.00 saving

I wouldn't be surprised if the savings were more.

Depending on route the trip up to Darwin will be over 10K Km and with fuel prices en-route over $200/litre it may be well $300.00 and even close to the $450.00 cost. Any fuel savings after that will be bonuses.

E.G. if the fuel improvement IS 2 litres less per 100 Km (18 -> 16/L/100Km) and the average fuel cost is $1.90 per litre on a trip of say 15,000 Km (Sydney - Darwin via Qld - Darwin - Sydney via Pt Augusta from Whereis) then the savings will be $540 dollars - The Dyno was worth it.

However if the fuel savings is less than 2 Litres/100K then you only save about $135 for every half litre/100 Km in reduced fuel use.

Diana

Whats sort of dyno does Spiro run?

Dyno Dynamics

I didn't really see the ratios as the computer screen only shows the pluses and minuses.
I am a little confused as seeing it has closed loop it should be 14.7:1 at cruise. When I asked him he said about 14:1. Buggered if I know.

With regard to the timing he plussed 10 degrees on light throttle tapering to 3 degrees at high TPS values. Again I do not think he pushed it very far, as I believe vacuum is 15 degrees and there is no vacuum . So at 2000 RPM I would expect 8 degrees static plus 10-14 degrees centrifugal= 22 degrees plus 10 degrees would be only 32 degrees.
I read that a Buick liked 40 degrees at light throttle and 3000RPM!!! . On second thought that would be about 40 at 3000RPM.
Dyno read out
Attachment 9719
Regards Philip A

Lucus , just a few other comments.
The Thor gives away 10% peak power for 50% gain at 1500RPM to about 2500RPM. I know what I like.
I understand that a 14CUX does not deliver additional fuel after about 4800RPM. So a Wolf/Haltech will always give much better peak power on a dyno .
The 68KW is (I assume by the speeds) in third gear. The numbers are higher in second. According to Graeme Coopers dyno about 80Kw.
So if i gained 20% then around 90 or so.

I have to be careful here because I added the closed loop after the last Cooper tune. I may have lost some with weaker mixtures.

According to Spiro the slump in the midrange is an artifact of the torque converter slip . It doesn't happen with a stock manifold as the Thor makes so much more power down low the TC is much looser.
Regards Philip A

Thats interesting that you say that Phillip,
I can cruise along with the cruise control set and slowlty wind the timing upto and past 40deg and the TPOS decreases until about 45deg after that is starts to increase so obviously the torque drops off past that point. Im currently running aprox 38deg max timing and the difference that made was astouding.

I've actually gone away from close loop for the time being as i found i could control my cruise afrs's better with out it. i can set my cruise afr's to 15.5 and get them to the point i get less the .2 change at cruise

I recently went down south for the weekend and cover 330km's on 55ltrs.
This average out to 16.6ltrs per 100. I probably did 2hr of beach driving (including full throttle runs up sand dunes) so im pretty happy with the result.

Phillip, i didnt get to read you second reply about the thor manifold before i posted my reply. I totally agree with what you say about developing a large power spread over a peaky top end rush. My car makes peak a 4500rpm. I will post up my dyno chart tonight so we can have a look at the difference in power delivery between the thor and old school plenum.

Im defiantly interested in swapping to a thor manifold. where did you source yours?

My 5.0L stroker running a Thor manifold and Haltech full ECU did the run to Melbourne and back (albeit just the vehicle - loaded for a holiday) using 13.6L/100km running 35's and 4.11's

Around town light footed it used 17-18l/100km

Heavy footed was a whole new story