FD:OC Dyno Day Results and Comparisons (04 Nov 18)

[cib24]

Hey all,

I am pleased to finally attach the dyno results from the FD:OC dyno day. First, let's begin with the raw results in order and reported modifications as we knew on the day. Note that the dyno speed setting was incorrect and in the next post for the comparisons I have attempted to correct the results accordingly as the dyno was off by about 250-300 RPM on average throughout the rev range for each run - so, your results should be shifted to the left and your power will drop off sooner than your printout shows by said amount.

1. Martin17: Bridgeport, EFR9174 IWG @ 1.0-1.3 bar, 3" exhaust, AEM coils, 850/1680 injectors, V Mount, water injection, Link ECU
Boost fluctuations due to exhaust system being too small
501hp / 376lb-ft

2. Advocult: Street port, lightened and balanced, Owen Developments (GT35 Copy) @ 1.1 bar, 3.5" exhaust, AEM coils, 850/1600 injectors, V Mount, water Injection, Adaptronic M2000
444hp / 333lb-ft

3. TougeMonster: Street port, Turbonetics T72 @ 1.0 bar, 3" exhaust, associated fuel and intercooling
413hp / 314lb-ft

4. Luke: Street port, Turbonetics T61 @ 0.95 bar, 3" Exhaust with 2" back box, AEM coils, 850/1680 injectors, FMIC, Apexi Power FC
2" back box choking spool.
401hp / 307lb-ft

5. jdmr_neil: Exhaust porting, Porsche K27 @ 1.2 bar, 3" exhaust, associated fueling, FMIC, water injection, Apexi Power FC
381hp / 323lb-ft

6. MKZ7212: Street port, BNR sequential twins @ 0.9 bar, 3" exhaust, AEM coils, 550/1680 injectors, FMIC, Apexi Power FC
362hp / 263lb-ft

7. rxt: Extended street port, sequential twins @ 1.0 bar, 3" exhaust, associated fueling, V Mount, Apexi Power FC
349hp / 263lb-ft

8. MightyCondor: Street port, EFR 8374 @ 1.0 bar, 3" exhaust, associated fueling, FMIC, Apexi Power FC
Exhaust manifold leak causing low power
342hp / 272lb-ft

9. NoisyNelly: Extended street port, non-sequential twins @ 0.8 bar, 3" exhaust, stock fuel, Apexi Power FC
329hp / 256lb-ft

10. cib24: Stock ports, sequential twins @ 0.95 bar, 3" exhaust, HKS Twin Power, stock fuel (hotwired pump), SMIC, Apexi Power FC
Major heatsoak on runs. > 65 C air temps caused reduced boost.
328hp / 268lb-ft

11. Liamc111: Stock ports, T04Z @ 0.9 bar, 3" exhaust, stock fuel, Apexi Power FC
313hp / 240 lb-ft

12. initialDean: Stock ports, 99-spec twins @ 0.8 bar, downpipe, cat-back, Apexi intake filters, Apexi Power FC
290hp / 249lb-ft

13. Ceylon: Stock ports, 99-spec twins @ 0.75 bar, cat-back, Stock ECU
289hp / 245lb-ft

 

[cib24]

Those numbers are all nice and good but how do they stack up when we compare them to each other? Let's start with the cars on twins using Ceylon's car as a base since it is on the stock ECU and is unmodified minus the 3" TGS twin tube cat-back exhaust.

Note, the graphs from here onwards are corrected as I mentioned in the first post. This means that the crossover point is a bit earlier than 5252 in order to show the correct ramp up in torque and drop off in power at the high end. For example, on Ceylon's car the dyno was showing that his car was spooling to peak torque on the primary turbo around 2850 RPM but with the correction it is closer to 2625 RPM.

The error on the runs was noted looking at my own chart where my car rev'd out to 8400 RPM, but my car can't rev past 8100 RPM without hitting fuel cut, and when comparing it to my chart from 1 year ago, it was obvious that something was off. The dyno operator on the day confirmed that the speed setting was incorrect so below are the adjustments.

 

[cib24]

Here is how Ceylon's car compares to initialDean's which is only slightly more modified with a downpipe, Apexi filters and a Power FC tuned for 0.8 bar.
Not a lot in it. Ceylon's car reaches peak torque on the primary very slightly sooner than initialDean's car, but Dean's car experiences greater torque on the primary and evens out with Ceylon's car on the secondary after the transition. The more free flowing exhaust and intake on Dean's car contribute to a less drastic drop off in power at the very top.

 

[cib24]

How does the base car compare to my car which is a stock port car on older twins running 0.95 bar (on the day) and a freer flowing exhaust?
Ceylon's car achieves peak torque about 250 RPM sooner with his 99-spec twins than my car. Despite my high AITs holding back my peak boost level of 1.05 bar, and instead limiting me to 0.95 bar and some pulled ignition timing, the extra boost and larger exhaust setup show clear gains throughout the entire RPM range, and a more progressive drop off at the top end. Peak torque is on average 20lb-ft greater across the primary and secondary.

How does it compare to a street ported car at 1.0 bar on twins?
The street ported car achieves peak torque on the primary about 650 RPM later than Ceylon's car. Torque is in line with Ceylon's car showing the improvements that the 99's bring in factory form, but this is also due to the way this car was mapped. After the transition the street ported car walks away and pulls for another 750-850 RPM at the top compared to Ceylon's car before power starts to drop off materially.

How does the stock car compare to a non-sequential setup with a street port at 0.8 bar?
The street ported non-sequential car comes online like a single turbo. It loses to Ceylon's car in torque and bhp until about 3800 RPM and it finally achieves peak torque around 4000 RPM. After 4000 RPM it begins to slowly widen the gap from Ceylon's car despite running nearly the same level of boost at 0.8 bar to Ceylon's 0.75 bar, and at the top end it acts like the other street ported car on twins and pulls for another 750 RPM or so before power starts to fall.

And how does it compare to a street ported car running BNRs at 0.9 bar?
The BNR's are setup sequential but due to being larger turbos they are laggier than the stock twins. Similar to the non-sequential car, the BNR's play catch up all the way until about 3900 RPM where the power and torque passes Ceylon's car. However, the transition is quite slow and the torque dip is pronounced, and as a result the BNR's do not surpass the stock car's hp and torque again until 5700 RPM. After this point the BNR's take off and achieve the highest peak horsepower of the day for twins near the top of the car's rev range. No doubt the surge once the secondary kicks in is immense but the primary and transition performance leaves a lot to be desired. Perhaps tuning refinements can wake up the setup further.

 

[MKZ7212]

Some great info Roy thanks for putting the work into this, I was going to mention I did find an issue on mine (BnR twins) the primary turbo has a take off tube for vac on the cold side, this whole piece had come out and wasn’t inserted into the housing so could cause some lag (hard to say how much) but has since been resolved. Hoping to get a remap to resolve some over fueling, increase boost and fine tune new AEM coils so will post back results

 

[Robbo80]

Interesting results, top man for taking the time to put all this together

 

[jdmr_neil]

Again top work Roy, i can imagine this was quite a time consuming task. Very happy with my power and torque especially how it feels up through the gears.

320lbs by 4.5k I'm very happy with that!

 

[cib24]

How does my car's stock port twins compare to street port twins in terms of power delivery?
Had I not had air temp issues I think my hp result would have been similar to this car with a final result around or above 350hp instead of being limited to 328. The street port hits peak torque about 300 RPM later than my car on the primary turbo as you would expect given a ported car shifts the power band to the right. My car drives the primary harder than the street port hence the greater torque and power delivery. Without knowing the mapping detail for the street ported car, it could be simply that my primary boost level is set higher than my secondary boost level and the street ported car is set for the same level of boost on the primary and secondary. Boosting the primary harder is a trick by tuners to flatten the torque curve and try to smoothen out the transition. If my car had more fuel the transition in theory should be a lot less pronounced as the primary could be pushed even further but my injector duty is already over 95% in cold weather so there isn't room to try. In any case, the street ported car breathes significantly better on the top end without the restriction of the stock air box and a high flow cat like my car, and it makes good power all the way to about 7500 RPM whereas my car starts to fall off dramatically after 6750 RPM.

How does my car compare to the BNRs?
Very favourably. Power and torque are better everywhere until about 6200 RPM where the BNR and the extra breathing capability of the street port take off. In fact, at 2800-2900 RPM my car is making 260lb-ft whereas the BNR car is making 140lb-ft. I think the BNRs have more in them under the curve and the tune could be further optimised to bring that primary on harder and increase torque significantly over the course of the rev range. The transition is likely to stay slow compared to stock twins as that is the nature of these turbos given the larger housings.

Finally, how does my car compare to the street ported non-sequential car?
This car placed 9th at the Dyno day as it beat my car by 1hp. It actually has an impressive result for only 0.8 bar in terms of overall power but the proof is in the pudding that non-sequential simply can't match the sequential setup when you have it working properly. Still, run the non-sequential car harder in terms of boost and optimise the map and you can expect results comfortably beyond 350hp and likely a 200-300 RPM quicker response.

 

[cib24]

Now, it's time to transition to looking at the stock car vs. single turbo setups.

How does that old Porsche K27 turbo compare to Ceylon's stock car?
The K27 is a mighty little turbo at 1.2 bar. By 3100 RPM it surpasses the torque of the stock car and throughout the rev range, and until its torque falls off it holds an 80-90lb-ft torque advantage over the stock car. It is quite a small turbo and by 5700 RPM torque starts to fall off in a material way and peak power takes a dive at about 6350 RPM. This is a great street turbo and if you manage heat on the circuit by shifting around 7000 RPM or just before it will be a great turbo on most tracks in the UK. Given how quickly peak torque arrives compared to the other singles on test it must be quite a tyre burner. The K27 is relatively unknown but judging by its dyno chart it reminds me of the elusive Apexi RX6. I wonder how the EFR 7670 would compare?

How does the K27 compare to my car?
It is a little closer but again we are looking at a 50-60lb-ft advantage once the K27 is on song until it's power starts to drop off about 500 RPM sooner than the twins car, but by then it would have walked away anyway given the torque and horsepower advantage.

 

[cib24]

Now to compare the rest of the single turbo cars to the stock 99-spec to see the differences. Please refer to the first post to understand the setups and where some cars had a few issues holding consistent boost or making the right kind of power. In any case, the curves still tell a lot even if the ultimate figures (such as the 8374) are not where they should be.

 

[cib24]

How do the singles compare to the winning car of the day, Martin's bridge ported EFR 9174?

EFR 9174 vs. GT35 Copy
The Owen Developments turbo (GT35 Copy) does quite well hitting peak boost only 400 RPM later than the EFR although it's torque as it is ramping up is materially less. Not bad for a journal bearing turbo. The EFR gives glimpses of where it's peak torque could be if the car could hold 1.3 bar...it is currently restricted by a 3" exhaust system which doesn't flow enough. With a freer flowing exhaust system I would expect the EFR 9174 to deliver in excess of 360lb-ft of torque from 4250 RPM and for the curve to look a lot more like a table top. Both cars are setup to breath up high and they make good power all the way to just over 7000 RPM before gradually falling off.

EFR 9174 vs. T72
The T72 has a progressive ramp up which means it might be less of a handful than you would think on a circuit, but peak torque doesn't arrive until about 5000 RPM. This car needs to be pushed harder in terms of boost but the owner didn't have water injection installed yet. As is the case with all of these singles except for the K27, run these turbos hard, i.e. beyond 1.3 bar and they will spit out really nice results. This T72 could easily exceed 450hp with more boost and refinments made to the map.

EFR 9174 vs. K27
The K27 runs the show until about 5000 RPM by which the EFR simply takes off. The K27 has done it's best shortly after 6000 RPM whereas the EFR pulls and makes great power beyond 7500 RPM. The top end of the EFR is savage and makes this not only a great track turbo choice given it's decent response of full boost by about 4250 RPM, but it is also well spec'd for a car that likes to try the larger tracks like Silverstone and Spa, and it would no doubt perform very well on a drag strip.

EFR 9174 vs. EFR 8374
Here we have two cars with the same compressor wheel but a different sized exhaust wheel. Whilst the EFR 8374 car had issues on the day, namely a blown manifold, the boost characteristics are still quite telling. The EFR 8374 hits peak torque at 3750 RPM compared to 4250 RPM (500 RPM later) achieved by the EFR 9174. The EFR 8374 is likely to have even better respone once it's exhaust leaks are sorted out and it may see peak torque up to 200 RPM sooner. In any case, the EFR 8374's exhaust seems well sized given the table top torque cruve attributed to it whereas the EFR 9174 needs at least a 3.5" system to breathe properly. Which turbo would you run? The EFR 8374 looks quite good and seems to have a top end that isn't all that compromised but the power potential of the EFR 9174 is quite impressive.

 

[cib24]

What are some of my takeaways after putting all of this data together?

Twins are quite impressive out of the box and are great for street performance whilst also managing to hold their own on the track. They deliver a very broad torque curve and allow you to rev the car out to at least 7000 RPM before you need to think about shifting. Adding in a street port to the twins does wonders as it sacrifices a little bit of low end grunt for an extra 750 RPM (or thereabouts) of power at the top end, a great feature to have for a track car or highway bruiser. From what I can see of the results my map is damn near spot on given it has been tweaked here and there quite a few times. However, I am keen to get my 99s back on the car, address my heatsoak issues, add some more water and fuel, and push the boost to 1.0-1.2 bar. Also, if my engine was not so healthy I would love to street port it and benefit from a greater top end.

When looking at the single setups it is obvious that they make more outright power, and particularly start to do so higher up in the rev range. They aren't as responsive as the twins very low down but most people running a single are interested in motorway pulls or track days where your time spent below 4000 RPM is limited. It seems apparent to me that building the right setup is quite difficult. It would seem that you need to decide on your turbo first and then try to build around it in order to get optimal results, in particular so that boost doesn't fluctuate so much. Still, going single gives you so many options from a punchy little turbo like the K27 to a larger turbo like the EFR 9174 which obviously has more than 550hp in it once that exhaust is sorted (and probably more than 600hp if the owner swallows some brave pills and decides to run 1.5 bar like the Americans).

At the end of the day, you can have fun with a stock car or a highly modified one but if you are going to modify you need to be very methodical about your setup to ensure you get the most out of it. I hope we can do another dyno day next year and I would love to see all of these owners back at that event with their niggles sorted out. Power will only go up from here (or down if any of you blow up your motors - haha!).

 

[MightyCondor]

Thanks for that Roy. All very interesting.

It's a shame there wasn't a dyno graph for my 342bhp run later in the day when the car wasn't heat soaked. The torque numbers were about 20lb ft better on that run too.

In any case, it's a shame that we don't get a straight comparison between working 9174 and 8374 set ups. I think your analysis of my issues is spot on. I'm only losing a small amount of initial response so I was surprised by how much I was losing at the top end on the day, but it's clear that my turbo isn't flowing enough to keep building a decent top end. Yet it still looks like a fairly typical dyno graph despite the issues, just a disappointing one.

I'll try and get it on the dyno again if I can get it working for long enough. All being well there should be more of a low end advantage for the 8374 vs the 9174 and the peak figures should be closer. It would be interesting to see where the 9174 pulls away under these conditions.

 

[Ceylon]

Great work Roy, dyno graphs tell a lot more than just numbers. I might try and bring both FD's next time, would be good to have an early 255PS stock car to throw into the mix for comparison.

 

[cib24]

Thanks for that Roy. All very interesting.

It's a shame there wasn't a dyno graph for my 342bhp run later in the day when the car wasn't heat soaked. The torque numbers were about 20lb ft better on that run too.

In any case, it's a shame that we don't get a straight comparison between working 9174 and 8374 set ups. I think your analysis of my issues is spot on. I'm only losing a small amount of initial response so I was surprised by how much I was losing at the top end on the day, but it's clear that my turbo isn't flowing enough to keep building a decent top end. Yet it still looks like a fairly typical dyno graph despite the issues, just a disappointing one.

I'll try and get it on the dyno again if I can get it working for long enough. All being well there should be more of a low end advantage for the 8374 vs the 9174 and the peak figures should be closer. It would be interesting to see where the 9174 pulls away under these conditions.

Yeah, I know but at least we can see the curves and by doing the comparison we can understand the response difference and also the power band difference which is key. With a healthy 8374 I am confident it is a 450-500hp turbo when run on a similar setup to the 9174, although I wager that 9174 top end could be worth 550-600hp.

It will be great to do it again next year and see how everyone's cars have improved.

 

[cib24]

Great work Roy, dyno graphs tell a lot more than just numbers. I might try and bring both FD's next time, would be good to have an early 255PS stock car to throw into the mix for comparison.

That would be great. Bring both on the same day because unfortunately you can't count on the fact that it is the same Dyno for it to spit out the same results on a different day. This is why this particular comparison among all of these cars is so useful, and let's be honest it is also really rare to have this luxury.

 

[Nas80]

Interesting to see another 8374 on the Dyno. Shame you had a boost leak really.

Here's mine, different Dyno but hopefully not way off.

Basic spec
EFR8374 IWG
Large oldone Street port
Id 1050x / I'd 1700x
3" exhaust with magnaflow midpipe and his silent power


I run just 1.0 bar I'm going to take it to 1.3 with water injection next year. I don't think 450rwhp is out of reach.

Yeah, I know but at least we can see the curves and by doing the comparison we can understand the response difference and also the power band difference which is key. With a healthy 8374 I am confident it is a 450-500hp turbo when run on a similar setup to the 9174, although I wager that 9174 top end could be worth 550-600hp.

It will be great to do it again next year and see how everyone's cars have improved.

 

[rob fd]

The 8374 is a savage turbo I made 454hp at under 1.2bar on stock ports

 

[shaunwil]

Awesome write up

 

[MightyCondor]

Interesting to see another 8374 on the Dyno. Shame you had a boost leak really.

Here's mine, different Dyno but hopefully not way off.

Basic spec
EFR8374 IWG
Large oldone Street port
Id 1050x / I'd 1700x
3" exhaust with magnaflow midpipe and his silent power


I run just 1.0 bar I'm going to take it to 1.3 with water injection next year. I don't think 450rwhp is out of reach.

View attachment 9063

The torque curve is interesting. Yours seems about 100 rpm ahead of mine in the initial steep climb, and then continues to build at a slower rate whereas mine goes completely flat. Both of your lines follow a similar shape to Martin's 9174 but with lower headline numbers