190.78bhp is a crude assumption of airlfow per bhp providing every other engine interaction is ideal. Plus in a running engine this flow is not consistant as in a flow bench, being pulsed sometimes backward up the manifold runner...So a target with unknown error, validated on chassis machines subject to error... For a start we do not know how much engine air during dyno testing, is actually being consumed by both engines. That is very important if the two are compared plus the mesurement devices have vastly different procedures ( Gurds tested in 4th on 450DS, PAB in 5th on CST type dyno, different engine loads etc) thus masking transparancy between results. So not a fair comparison in the context of the question unless there is a common reference to "walk" back to any errors on both sides. On the GS dyno, this level is where the highest plateau has been seen on stock hardware. When you come near this level options to go further become very limited. The torque is related to how much air the engine will inhale. The "bhp" peak is the point where the torque gradient falls off faster then the rpm gradient is increasing. So it is really not as important as achieving a broad torque range. Target to get torque as high as possible and worry about the BHP after. If the torque cannot be elevated higher then you have to attempt to extend the torque to higher engine speeds without loosing the lower rpm response. The other option is to spend thousands to chase numbers and potentially have the torque leading ( or decaying) to that "glorious" number compromised. To harness all this effectively you will have to look at gearsets, FD, tyres, suspension etc...
Thanks Brooky good info to know, as the revs rise it works out that the best inlet track should be less than the one I roughly quoted for 7000RPM. Good to know a performing engine such as Bargate's is not to far off - assuming it revs more than stock
Not really got anything I can put my finger on as one key element, just read up a lot on here before building and took the best bits the budget would allow for.... Having said that the OMEX200 mappable ignition and coil pack made a hugh difference. The engine must have more in it with head work and a change to TBs. The reason for such a strong bottom end was two fold... 1. A proper bottom end will be strong enough for future mods. 2. I ran out of budget when I got to the top . Sure is, this motor must have more potential in it. I've no idea, its not up to 300/350mm. Spot on Brooky, its not pretty or flowed/matched to the head. My Run at Noble was in fourth gear and the run at Chipwizards was in fifth gear. Noble plot.
PAB, You don't know what it's making at the wheels, do you? Your figures are only a kick in the ar$e away from mine, so just wondering. I seem to loose a lot through the 'box/geometry when measuring coastdown - which is to be expected I suppose based on the settings.
Both tests were done on a Maha machine which is good. I can see the DIN correction for Glen but not for PAB. Correlation still needed to match facilities. Looking at your testing and the one PAB has displayed here PABs car did achieve max torque of ~159.6lbft@5900rpm similar to your 159@6000rpm, but it is a different story with the rest of the profile. I have put the combined the two in Excel. Ess Three yours was very difficult to read, but got it in there in the end. PAB has more low down torque ~140lbft+ from 3700rpm vs ~130lbft +. from there the torque delta becomes even greater with a carb'd engine at ~159lbft@4700rpm vs 141lbft for the plenum'd ABF. After that Ess Three's engine starts to peak the torque and match PABs at ~5900rpm at 159lbft. PABs torque does drop off as fast as a regular plenum engine after 6000rpm, but saying that it neither would have Ess Three if the limiter did not kick in at 6800rpm. Pehaps after 6800rpm there may have been a penalty on torque gradient with the plenum'd car. Overall PABs car seems to be benefiting from the use of the cams, side drafts and 4-1 exhaust. I would not have expected a dip in torque from Ess Three's car sub 5800 rpm though. Back to base engine and a similar phenomena as PABs, in terms of torque profile was seen on infinity's when his std engine with specialised dress kit was tested. His richer than normal fuel mixture would have caused a torque reduction. Here the ITBs and custom exhaust seemed to have an effect of hanging on to torque ( improved engine filling) at higher rpm than seen in the vw_singh MK1. I could only imagine PABs car to broaden the torque range with ITBs, fix the dip at 5.2K and reduce and smoothen the torque decline after 5800rpm in turn putting your power number up. Torque may not go much higher though and may plateau at 163ish lbft. Changes such as these can only become transparant if the original conditions are recreated i.e the vehicle is tested on the same the dyno rebaselined then tuned or the difference in result from the recent NW CGTI day is properly understood and the conditons on the Maha can be recreated. The profiles seen above from the two fairly modified 2.0 16v engines, have benefited the higher engine speed range with engine breathing enhancements. Even though it could be argued that there is possible further work improvemewnt that can be done to both, these modified engines have superior high rev torque profiles to a std but highly optimised engine. Earlier testing on OE ABF long engine for infinity and vw_singh are combined illustrated below:- Without correlation the numbers between facilities are neither absolute nor comparable. With correlation we could have a very large database of useful information and show more scientfically that may be possible to use an unmodified head, achieve high torque and 200+PS, all other things equal. Very interesting though.
Excellent stuff as always Eddie. So, looking at Ess three's Plot over PABs and the similarity in torque plots, If Ess three's limiter was higher and the torque continued to follow PABs, then the Mk3 is already a potential 200bhp Gurds
Yes. But I do not know what would have happened post 6800rpm if the rev limited was set to say 7500rpm. Peharps Ess Three could enlighten why the stock rev limit was left in place. The torque drop out pre 5800rpm is interesting. I would have thought this area would be stronger.
Can anyone enlighten me on the compression of Ess Three's engine. Was it running stock internals here? Eddie great job, I can see Infinities torque curve and how it carries on, I have plotted mine onto an Excel spread sheet along with Gurd's and Infinities, my torque drop off is in between the two at the high RPM's. Every small increase in torque past 5200RPM seems to bump the BHP right up, for example an increase from 147LBFT to 156LBFT @ 6500RPM would possibly see 100BHP per Litre on my car.
Hey Tom. I believe the bottom end in Ess Three's motor to be factory comrpession, stoke, bore etc etc. Gurds
Wasn't there two rev limits on ABF ECUs? I thought one was at 6800ish and the other just over 7000? My limiter is set at around 7300 IIRC, slightly above standard, as I wasn't sure how many revs the valvetrain I'm using was good for (lightweight hydraulic lifters, standard twin springs, titanium retainers) so played safe. It seems OK for the cam choice so far. But, it'll need to go up for the 268/268, 276/276 or 276/268 combos I'll no doubt end up running once the ITBs go on. The ECU has never been 'properly' re-calibrated. With the Emerald ECU fitted and a mapping genius doing the work, I'm hopeful the dip can be worked out.
Yes, standard internals. The bottom end has never beed touched. The compression will be fractionally higher as the head has been mildly skimmed (don't know how much) and the head has had work. A higher CR is on the list...I've got a spare ABF to play with now, so one day...
I'd say somewhere in that ballpark yes, possibly even more. As an example, strong running comp spec 8v's making 190-200hp have inlet flow in the 93-103cfm, so a std head at 110cfm should be able to make power in that region. Bare in mind thats head flow... adding a std 16v plenum & airflow meter or metering head will knock off more flow than the open induction does on the 8v examples above, so that will balance the flow out. You then have to take into account the camshaft spec needed... std injection systems arnt keen a too radical a cam, so further knocking back the potential in std type injection form, but not such an issue on carbs or t/b injection. So on a plenum/std injection spec engine you are likely to need tame cam & head work to get to 200hp, on open induction, the head should support the power potential, but a decent cam spec will be needed, plus then poss forged pistons to cope with the extra c.r... so we're now back into what spec.... plenum/std type injection/tame cam/head work... or open induction/std head/radical cams/forged pistons.... cost v's power band etc... As usual... that word compromise comes up again.
It certainly does, thanks for all the imput so far, it is proving to be very informative. Does anyone know of other high powered 16v's using a standard unported head? If so what is their spec and how did they accomplish the power?
I recently sorted the issues with mine, power now at 188hp @ 7500 and 153 ftlbs @ 5750 on a TVU approved dyno
I think it would be go to have a full inventory of everybody's engines specs and power outputs for a central database for people to access. it would be interesting to see the specs + cost = power outputs yes i know some will be on different RR Lottery's etc but it would give us somthing to work with.
