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Finally got my car onto a dyno for some quick power runs. Zero mapping - I just ran it as I've been running it on the road, mapped by me on the road.
The graph is a comparison of it turboed versus when it was NA. Calcs back to 235 hp @ wheels on Dyno Dynamics calc. The only bit that isn't right is the RPM sync. The car hit the soft limiter at 7100 and reved to 7170 odd but the dyno pull only goes to 6,500. We had a quick look at the sync and at 3050rpm ecu is was showing c.2960 on the dyno. The error at the top end if it is an error looks greater than this.
I also ran the car on wastegate only pressure which is 6psi dropping close to 4 psi at the top and at a flattish 6.8psi. Results below:
You can see the torque drop off as expected running a flat boost target. As the TD05 is large for my power - it appears to work quite well ramping up the boost at the top end to fill the area where torque usually drops.
The load on the dyno was a little low to achieve my exact boost targets - I was about 0.5 psi down 8.1psi rising to 12psi. I've since turned it up a tiny bit more on the road because of greed. I'll get this map tested at some point. Boost map is currently:
And log from a run through 4th last night:
Realise the photo above looks like it was taken on a potato - basically 2nd graph down in the shot, boost is on target on the road to the boost map shown above.
All good fun until she pops. Took 9% extra fuel to hit target AFR compared to the dyno run at 270hp. Hard to tell difference on the *** dyno as it simply accelerates to the limiter due to torque being held.
More people should use a TD05-16G on the miata its a really good turbo always has been and so much better than td04's which IMO suck *****.
I don't have experience on the TD04 to comment in detail. The selection of after market and DIY exhaust manifolds, piping sizes, intercoolers etc. used on miatas is so great that its hard to assess a turbo as a standalone unit easily.
In my case I have a relatively long manifold with large area runners compared to the Mazda exhaust ports and full twin scroll manifold, turbine housing and wastegate pennies. This makes it double tricky as a straight comparison as it should be a good manifold, well matched and twin scoll is expected to increase response and possibly efficiency. How much against a conventional TD05 - who knows without accurate back to back testing in this scenario. I have observed numerous people saying TD05s are too laggy in their experience of conventional TD05s bolted to existing TD04 manifolds.
You can see the response of my system on my last video above. That is the same map as run on the dyno. Other items that may help is using the matched Mitsubishi evo intercooler. I basically decided I would use Mitsubishi's R&D where I could to aim for a matched system as its been good enough for them in early Group A and lasted many generations winning in Group N rallying with slight tweaks. The system should be good for c.320hp wheel, c.370hp flywheel tops which would be more than enough to start with should I build an engine and hopefully not limited by VVT head.
I'm just happy with it as a system - just hit over 3,300 miles turboed and its never shaken a nut or bolt loose, not used coolant, not burning oil etc. Its probably up there ready to shake the rods loose.
Been through the logs etc. on the dyno runs. HP versus boost looks too good to be true IMO. Its making more than 100% performance per boost. At first I thought this was a mechanic around VE increasing compared to NA.
Now I'm not so convinced. I think the car has most likely risen off the rear roller and artificaially increased its ramp run hp by not having turning the interia of the second roller fully even though that inertia is used in the wheel power calculation. I believe this error can increase the figures on a DD rolling road if the car is not strapped carefully and we were in a mega rush. I was in the car at the time so did not watch it but also was not aware of an issue at the time.
I'm going to get the car back on this dyno, take more care and see what we get. I'll also try to get it on another eddy current dynojet. All in good time.
I'd estimate the car at c.250hp just now and this is probably why the rods are still in it as the mid range is conservative boost. I'm still very happy with perfromance.
Had another shot on the dyno this weekend. Spent my main tuning time optimising the cruise ignition timing. At the start of the session I did a few full boost pulls and played with the timing and boost to flatten the torque a little more.
Still seeing speed run out on the dyno recordings - it peaks at 7.1k on the ecu and pulls to 7k solid as per my boost target map then drops off for safety to the limiter.
Results are c.238hp @ wheels a 13.5psi top end as per first graph below which is fly calc and wheels recorded. Second graph is when it was NA versus where it is now. Car is driving really well.
I've done a few winter mods and still finalising items for this season.
Took the car out for a little blast last night and to see what VD pumps out. Graphs below for both Dynojet and Virtual Dyno correction factors. VD CF brings the figures much closer to what I recorded on the Dynodynamics Dyno so probably best comparison for me. Fingers crossed - she's still a runner.
I added a sprinkle of boost to the top end of the blue one - was targeting 14.5 at top but looks like I may finally be out of WG spring. Will spend a bit of time on it pumping up the duty but think it is already over 2x past WG only values.
I was a very naughty boy at the weekend. Added toluene to a tank of pump fuel for protection at the track. It appears to have soured the tank and my knock detection lit up like a christmas tree. The toluene was purchased over 12 months ago and appears to have a limited shelf life in the container it was in.
Being stupid - I put enjoyment on the day ahead of the engine and sent it for 16 runs up the hillclimb and left the ECU to pull timing through its closed loop knock control.
Car is still running fine but I'm convinced it is breathing blue smoke where it did not used to as I saw it on a friend's video - could be a different issue. Pulled plugs which were new ahead of the event - they are all fine. Cold compression test returned 188psi to 192psi across all 4 pots. Put a low quality camera in the chambers and a number of the pistons do look a mess on the top. Might get a better HD camera to confirm. I'll probably get a friend to leak down test it as a further check tomorrow to give hints of where it is at.
Either way - its most likely getting sent till death do us part. Poor little sod.
Leak down test results from the weekend: 4 to 7% leakage across all cylinders - exact same result as when tested before turboing the car. That is a mint result on my friend's tester on this size of engine.
I'll take it. I ran the fuel carefully out of the car, fresh tank of premium unleaded, messed around re-introducing timing and its all singing the right tune.
Happy that it verifies my knock detection can closed loop knock retard setup.
07-31-2021, 06:23 PM
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