Smudge's ITB'd 190PS (almost) in further ABF 16v dyno development. 03-06-11

In another instalment of ABF NASP 2.0 16v optimisation, Tom's Mk2 Golf with an ABF powerplant on a std bottom end, flowed head, motorcycle itbs and 4-1 header is reverted to ABF OE 051 camshafts. Once the engine is optimised, a live test, using a G meter is performed to relate real world performance with the engine's capability.

Background

Originally this exercise was planned to investigate any performance advantages that would occur by finding the best fixed piont from Piper 264 camshafts on this specific engine, using the externally adjustable cam gear and a recently purchased group buy - the internal cam gear.
As the original internal gear was already removed from the piper cams and refitting the adjustable unit proved to be a bit invovled for the owner, it was decided to reinstall the original "051 101/102" camshafts and use the pre-developed test plan to investigate what WOT performance could be achieved on almost a std head and block with addition bolt ons.

Test procedure

Testing began by baselining the vehicle as received.
Once baselined, adjustments to the external cam gear were made 2 at a time and tested, optimising the engine calbration until this best cam position was found.
Initially the test started with the cam at 4 Adv. This was then adjusted to 6 Adv ->
2 Adv->0 -> 2 Ret-> 4 Ret->6.5 Ret and finally back again at 0

For some tests, adjustments were done to the engine calibration to optimise each step.

Smudge slacking the cam gear getting ready for the next test stage.




Cam gear set at 2 Ret



Cam gear set at 0 after sweeping through advance cam positions.



Cam gear set at 6.5 Ret , the maximum retarded cam position for the exercise



Cam gear set again at 0




Results
It should be noted that not all test results are shown. Shown are the results for baselining, to outer test limits and the final optimised cam position.


Baseline cam at 4 Adv after fuel mixture tweaks

Test	Power bhp@rpm	Torque lbft@rpm	Comments
Baseline 4 Adv	174.9@6800	157@5250	calibration matched

In the baseline the AFR was optimised to achieve LBT at WOT to the redline.

Cam advanced 6.

Test	Power bhp@rpm	Torque lbft@rpm	Comments
Baseline 4 Adv	174.9@6800	157@5250
6 Adv	171.6@6900	156.9@5290

At this setting the engine started to become very vocal at high rpm and struggled to 7200rpm. AFR at high rpm also became richer than the baseline and sightly leaner at low rpm. There no real loss in low speed engine torque.

Cam retarded 6

Test	Power bhp@rpm	Torque lbft@rpm	Comments
Baseline 4 Adv	174.9@6800	157@5250
6 Ret	179.3@7000	148lbft@5100

At this setting the engine sounded very vocal from lower revs. Response was very sluggish but it did rev to the redline of 7700rpm. There was significant loss of torque sub 6500 rpm. Fuel mixture remained at LBT at high speed but was much richer than LBT from low rpm.

Cam set at 0

Test	Power bhp@rpm	Torque lbft@rpm	Comments
Baseline 4	174.9@6800	157@5250
0	186.9@7200	159.8@5200	*Airfliter removed

For this last test the airfilter was removed and this resulted in a small change in high end torque, allowing the vehicle to achieve 187bhp (189PS) @7200 rpm. Previously in the test sweeps, when the vehicle was first tested at 0 cam setting and the peak result was 185.9bhp@7100rpm with the airfliter on. It is debatable if this small measurement delta via w/o airfilter, would be felt in real life. At the zero setting the mixture, when compared to the baseline had to be en-leaned at high rpm due to improved pumping efficiency. LBT was achieved for all speeds at WOT. Spark timing advance adjustment made no significant difference to peak torque, but could do with refinement in areas where there were small dips in the torque trace.

Removal of airfilter.


ITB velstacks exposed to dyno fan




Comparing dyno meansurements with real vehicle acceleration.

Here, data from the G meter, obtained just after the successful dyno session, was used to compare and validate torque profiles from the dyno. This information can be used in choosing appropiate overall gearbox ratios providing the G meter trace correlates to dyno torque profile.


Gs in 2.11 020 Second gear with 3.67FD.

We can see that vehicle acceleration in gear (2nd) matches very closely what was measured on the dyno, in terms of profile with maximum Gs occurring at ~5200rpm. On road the cars suspension is working harder and does affect the smoothness of the G meter data but generally the shape from engine torque is represented.
As the peaks are in the correct place this information can be put into a gearbox spreadsheet to determine where the optimum acceleration range will be as the vehicle is driven to WOT on a track.

How does it drive.

Without the reader being present it is difficult to be objective. However the easiest way to represent the way this vehicle drives can illustrated by using G readings from typical std correlation 16v vehicles that have been used in the "typical 16v dyno plot" thread.

These vehicles owned by gad (Dav's ABF Digi correlation car) and Chris Eyre ( barn stored KR car) are very well known to forum and the Gs vs engine speed are shown in the plot below along with smudge's.
It should be noted that all vehicles are MK2 Golfs with 2Y 020 gearboxs (gad=AUG/1.94 2nd).
All vehicles accelerated in 2nd gear.
All vehicles run factory recommend wheels and tyres.
All vehicles ran full interoir and tested with 2 adults ( driver and passgener on board.



Smudge's car has a clear advantage in terms of straight line acceleration over all the other vehicles. None of the other vehicles are slow mind, but at 0.39 G@5200rpm, smudges MK2 has as much acceleration at mid to high engine speed as a Focus 2.5 I5 ST has from low revs in a similar gear. At 7000 rpm this vehicle also has as much torque ~140lbft as an OE ABF engine would have at its peak near 4500rpm.

Conclusion.

The best cam setting, w/o internal verniers on OE 051 units, is at 0.
Further engine improvement requires a step in compression and larger cams, along with a new engine map. However with and engine speed range this usable and broad it may be possible to extract significant vehicle performance with a final drive change for low overall gearing.
Overall an interesting experiement and and yet another example of what the OE ABF engine ( Head and Block) can achieve with careful tuning and bolt ons.

Regards
Toyotecwerke

 

Very nice analysis Eddie. Just goes to show that the torque curve can be extracted on the road with a simple G meter. Nice My Iphone has one in it.

Gurds

 

I think more people should use this application, if it is any good, to get a rough understanding of where the max acceleration is at WOT.

 

+1. Would like to see how the Dynolicious app compares.

Another good essay there. Must be going toward a B eng Hons in VW 16V engineering.

 

I've dabbled with Dynolicious too, and used it to improve the setup of my track car, back when it was on Kjet. It would be good to compare it to another device to see how accurate it is. The results seem to make sense though. I always worked on the principle that if I did 3 runs and took the average, it would even out the human error in gearchanges, wheelspin, etc.

I think you'll find it's valve-count agnostic though. The academic principles here will work just as well with 8v lumps

 

The principles will work on any engine even those with less ventilage

 

Ahh you will have to be very careful Mike. I tried it on the driver and next thing I knew, The G-Meter in the Iphone exploded in an array of sparks, probably from the extreme talks generated by my engine. . So now I test my car in 5th gear to calm the thunder.

Gurds

 

must be that cam!

 

Good work again! maybe you should the on the clubgti payroll!

Am I right in thinking that any adjustments will need the fuelling optimised to realise any gains?

I ask as my 8v has an adjustable sprocket currently set at 3 deg advance, I've thought about fiddling with this for a while but wasn't sure if its worth it without fuel adjustment. Its on digi and was set up at stealth with the current timing.

cheers

 

Also just to take the thread to its logical conclusion...VVT? Just putting it out there

 

Great write up, many thanks for putting all the time into this Toyotec, I know it is a lot of hard work and all out of you own time for the benefit of others

 

Great information.

Tom, you have PM re the `0 degrees` on the vernier.

 

I have been chatting to Nige P and he has pointed out something that may be of significance. My head has been skimmed on rebuild (no2 at least) this should reduce the head to block height and will affect the timing slightly. It is all dependent on the amount removed but Nige mentioned it could be as much as half a tooth or near 2 degrees...

For my application it will be advanced, by how much i do not know. Food for thought...

 

Did you not set the cams/crank to proper TDC using DTI's etc?
Half a tooth though, thought a tooth was approx 4mm wide? How much have you had taken off lol?

 

Not displayed were test results for 2 Adv and 2 Ret. The profile and peaks for these settings were similar but less than ideal at 0. In real life I would not have thought that the driver would notice the difference in feel for either of those optimised settings i.e. cam at 2 Adv or 2 Ret. However directionally the best fixed cam position was at 0.

 

Or donations to the club are always welcome to ensure the facillites and resource are covered

You are controlling a combustion process so all inputs will require matching, if you wish to achieve maximum torque for a speed load condition. For optimising an engine my finding is Digifant 2 is limited.

 

That is no problem.
The hardest part was extracting the information for dyno/G meter and formatting it so that others may benefit. This does take time to ensure the information has value.

 

Lol, that's the thing, the last skim was just a clean up, but I do not know the heads history... I imagine it was again just a light skim so probably very little. How much would a couple of light skims measure?

 

I've heard of people talking about 4 thou, as a light skim to clean up a head face.

 

Really nice write again
Well done eddie
And nice to see the smudgemobil evoluate
Romain