Here is a summary of the ABF 16v results that were generated on Thursday 18th back to back. The vehicle's used in this summary were; Ben S, MK2 MS with optimised calibration and Ben S custom inlet manifold. w/ 8v exahust system. rubjonny, MK2 chipped ABF digifant 3.2. w/o cat and with 2.5 inch cat back exhuast NatsABF, MK3 16v digi 3.0 on nominal hardware w/o cat. Here is a plot summary of the vehicles on their best display. Ben S achieved 157lbft@4500rpm (~150 lbft from 3500 to 5700rpm) and 162bhp@5900rpm rubjonny achieved 149lbft@4600rpm and 166bhp@6200rpm (145lbft@4.3K and 160bhp@6.3K on OE ECU) NatsABF achieved 136lbft@4300 and 147bhp@6300rpm In these results it is observed that Ben S custom mapped ABF with a custom inlet manifold had the most torque up to 5700rpm. After this point rubjonny's E-gay chipped Digifant seemed to hold on to more than 140lbft for a bit longer and even after, the torque decayed away at a reduced rate to the rev limit. . NatsABF car was on nominal hardware and shows relative difference between the VW reference and the MK2 vehicles that had various improvements. It is believed that rubjonny's cat back 2.5 inch exhaust system was helping the engine to flow more air at higher rpm where as Ben S' post downpipe 8v exhaust system is choking the engine when the air is approaching 160bhp of flow. This assumption for now, is backed up by the peaks of 5900rpm, a bit short for this type of engine at even these levels. This same peak is also achieved on the ABF K jet shown in another comparison also on a small bore post downpipe system. Ben, Natalie and John's vehicles can all be made to run very similar if, a) using Ben car as an example, the torque profile is spun counter clockwise with 4300 rpm as the pivot and 7200rpm as the handle. This will occur if the hardware restriction is located and updated and the calibration and custom hardware continue to work with the rest of the engine. b) John's and Natalie's vehicles are custom mapped using the Digi 3.2/3.0 ecu using lessons learnt from the vehicle above. This is what the theoretic plot for all the vehicles should look like all things being equal - please look at "Theoretic Ben MS Mani" profiles Can you 'easily' achieve 200 bhp from an ABF engine? To date my answer is no, not easily. Can you tune your OE ABF engine to be have strong pulling characteristics? My answer is yes. What are these "strong pulling" characteristics? Using the data generated at Garage Streamline and assuming all vehicles are in a good state of health, this is from a torque level of 150lbft and preferably spread over a wide rpm range of 3500 rpm to 6000rpm. This makes a quick and aggressive pulling car on factory gearbox ratios and inertia weight. Change gearbox ratios sensibly with a shorter FD and you have even more wheel force to amplify engine torque. Lose weight and gain some driving talent ( plus the rest) and you can challenge very expensive vehicles on a track! Regards Toyotec.
Basically the angry MS controlled 2.0 16v ABF is being choked by the exhaust system intended for a 1.8 8v I did want a Jetex but couldn't justify the purchase without proven benefits / requirement.
Saxon motorsport do a very good 'standard' replacement downpipe for the Gti championship boys.. that along with a decent full system?! Great development work gents, slowly putting all the information out there for everone.. Muchoes respect..
Dyno Development Toyotec, Many thanks to you and fellow contributors for this expose - - Ben S, I've unsuccessfully searched for information on your modified intake system - - post # please? re exhaust systems, has anyone used a manometer to check back pressure at the potential choke points of whatever system they're using? re early 6A/9A vs ABF heads, further albeit subtle flow improvements to the latter may be due to the eccentric, shallow "ditch cuts" machined into the combustion chamber on the spark plug side adjacent to the intake valve seats
Another good comparison thread. Would be great to tie in all the optimised digifant and k jet fuelled cars with megasquirt or stock spark control options into 1 place. Looking forward to seeing what figures my homebrew 2L swap might liberate when optimised. From my understanding the k jet system can still give excellent results with careful tweaks. Certainly equivalent to oem digifant in terms of peak power/torque?
One 2.5 in MK2 system is available for loan and evaluation before making a firm purchase of similar or better system. Sounds interesting - Ben S take note. Replied to your email. Thanks to Ben S, NatsABF and rubjonny for test data on their vehicles. These members have more details that were not posted on here. Good point on the manometer in the exhaust at different points. Just that we would have to convert a system to on what would be an everyday road car to validate then remove. This would be more accurate in detecting which part of the exhaust would cause an issue. In addtion to the visual head differences, described on here by myself and others, mrhillclimber has been flow testing the latter in your post and is comparing to the 6A/9A 051/373 units. As per 3hirty8ight the Kjet can be adjusted to give consistant fuel mixture at least at WOT but you are still limited to 1.8, 10:1 KR spark tables. As seen in the ABF K Jet car a good working KJet engine can be up there but with a much narrow window of optimised operation. This plot illustrates the point. Chipped Digi vs Aftermarket Toyotec mapped ECU vs Toyotec fettled KJet. All ABF engines . The K-Jet engine though very strong pulling, would be expected to ramp torque out sooner even with a good exhaust. This would be due to the mechanical limitations for adjusting to optimum torque. Low speed transients and steady state conditons would also degrade driveablity. This would not be a problem for the engines controlled by electronic systems for mixture and ignition.
Manifold is modified in length, volume and internally but is in development so until final version is manufactured and tested, can't release more info. for now here is the stock item vs modified item tested back to back in the same evening and both tests feature mature calibration. These results are already interesting as clear gains are shown, but the exhaust issue needs addressing sharpish *EDIT* incase it wasn't clear on the thread, this is the same car / engine / ms1v3 setup. Differences are: intake manifold & calibration
I noticed that all these cars had no cat. Nats car is an ABF in a mk3 that would usually have to have a cat fitted for MOT purposes. Is there any data on the effect on the standard cat has on output? It's due to my car still having the standard cat fitted. Wondered how much it restricts exhaust flow. A bit like in the downpipe effect on BenS' car. Been thinking about how a sports cat would benefit it. Although it's FI it should still relate.
I would expect the factory cat to have more of performance penalty on a boosted vehicle as yours. How much I cannot say. In this company though, NatsABF's vehicle, on is orginal bore exhaust system sans cat was performing as any nominal ABF vehicle and is used as a reference. It was never reported that the downpipe is deemed to be an issue on Ben S' vehicle as yet. It is what we call the 'cold end' or post downpipe part of the exhaust path are where efforts will be focused. The K-Jet ABF vehicle seems to be suffering the same fate and that has a 16v downpipe but a small bore exhaust for the rest of the system.
Im more than happy to lend my car to the development program.. I will soon have differnt ECU's to try too, one standard, and one with the rev limit raised to 7,600rpm. The chip 'stretches' the ignition curve over the extra 400rpm from what I gather.. It will be interesting to see what it does back to back with teh std item, with the same base ignition setting. I will of course be divulging the infomation i get.. :-)
after this benchmark testing, do you have plans of producing a tBbay style chip for digi 3.x in mk2 chassis? ie stock motor and ex system minus cat. im sure if you calibrated them on Dav's car it would suit most applications. addage of exhaust or breather mods would just be a bonus? id certainly buy one and im sure it will fund further research Paul
I read that primary length is determined a lot by cam choice? would be interesting to investigate what the 'correct' tuned length would be for std cam specs..
Maybe the standard item is better for idling and very low rpm, but I can't see how it is better than the experimental item for standard cams or otherwise when performance is the goal
How did (think its ) gurds car get 175bhp then ben s's get 157bhp, surely not all down to the 8v exhaust system.? Or would it be engine condition aswell. I thought with that result you was going to say in around 80% tune.
You are watching the wrong measurement. Watch torque and and the other vehicles tested. Then you may begin to understand why there were certain conclusions. Ben's car has had a bit of delvelopment since then and now feels much stronger to the redline of 7300rpm even in 4th by the seat of the pants. That is however my subjective opinion. A series of dyno validating tests with explaination will be done soon, funds and time allowing.
