Hi All, I've been asked to fit omex to an mk2 8v gti. I have not yet seen the car, I've been trying to read up on what problems I may face. Firstly I understand there will be no tps but a ford (dont know what one) can be made to fit? Secondly, there is no crank angle sensor, just a hall effect pickup in the dizzy? If this is the case can anyone point me in the direction of a cas that will fit or will I have to make a bracket and weld one up myself? The rest I hope I can deal with, as it should just be sensors etc. Any pointers would be great Thanks!
The prefered way to do the crank sensor (which I think you'll need to do with the Omex system) is a bracket on the end of the block just behind the crank pulley with a sensor mounted in it and a toothed wheel on the crank pulley. Some mount them on the front of the pulley without issues...some have. I personally mount them on the rear of the pulley to eliminate the potential issue of movement from the vibration damper...it's a bit fiddly but works for me. Is'nt there a digifant tps that can be used?...someone here will know....mike h, drunkenalan etc run stand alone with plenums. Must be a decent project to run on Omex...good system.
Thanks for the replies, I'm not going to hide this is for a customer I work with loads of ECUs just usually on Jap cars. Its a farily developed engine internally but with pretty standard ancillaries still due to the fact its on OEM ecu. I've had to weld brackets etc for cas sensors in the past but prefer not to if I can avoid it! And yes omex 600, will be using map based load for now and perhaps change to alpha-n later if TB's or anything go on (its a track car). Interested to know more about the TPS if anyone can help. Thanks again for the replies - appreciate it.
there are direct fit throttle bodies with TPS, but on the digi they tend to hit the fuel rail/fpr. here is trevs solution on a G60: http://www.clubgti.co.uk/forum/showthread.php?t=131523
Most throttle sensors 0-5v can work once you configure the range in the software for low and high. CAS can be hall or VR. There is a menu to configure the number of windows/teeth. I am not sure if there is a menu specifically for a dizzy's as most vehicle's I have worked with have either a 36-1 or 60-2 trgger wheel. Can check one of my projects and confirm though.
Sorry, thats not the problem. the Omex itself im totally familiar with, its the car I'm not. I was under the impression it doesn't have a TPS or crank sensor at all. but that seems the only things I need to work around.
No probs. Sounds like an interesting engine...maybe itb's are the way forward subject to budget. Couple of guys on here have done what yr looking for tho...I'll be doing it myself later this year...ask me in 6 months time!
It lives! Just fired up on the omex - currently running just the ignition in a rather crude setup - but it lives, and it means my new crank sensor is working. Very pleased about that, means I can now fit it properly, with fuel of course too
[YOUTUBE]ScNPGMPMMZw[/YOUTUBE] There we go, running as described above. Will be on the dyno tomorrow, made 118bhp before the ecu was fitted, which I thought was pretty poor considering its a built engine with cams. So hoping this will bring some decent gains.
Well power went from 111bhp to 124 bhp. Not as much as I was hoping, however its still on standard exhaust and inlet.
Not being a VW expert, this has cams flowed head, kent 270 cams etc etc, yet seems really down on what I'd usually expect from a similar setup on what I'm used too. How bad/good are the stock exhaust & inlet manifolds etc? Will upload pic later (probably tomorrow)
STD parts do have their limitations when the hardware is modified yes, but the we would have to determine how and if they are a limitation by viewing the WOT plots.
The stock manifolds will cope well above that power output, assuming those are flywheel figs. I'd think there's a little bit more potential in there, but only a handful of horses, in an 1800 8v. What's the exhaust on it? Any AFR readings. As per above, plots would be good. Where's the peak torque at?
As Mike said, not a problem on std manifolds..should make around 140 from an 1800 on that spec if all good bits, a bit more as a 2ltr. Peak power on that cam will be around mid 5k. The cone filter needs boxing in/splitting off from drawing warm air in...and check the cam timing...too much advance or retard will knock off 20hp with ease. You'll need to check lift @ tdc on inlet & exhaust to get a true cam position in relation to the true tdc point.
Hmm perhaps its cam timing then. AFR had little effect on max power so settled for mid to high 12's, I may have to see if the customer is willing to get it back on the dyno for me to play with. This stage was just get it going as-is as they want to take it racing later this week. Here's the graph anyway, lower lines are before ECU, higher after. Sure this will make sense if you have seen this before. 'Fusion' is me btw, didn't want to mention names as I don't wish to tread on toes of other traders etc, but I'm not too proud to ask for advice either with particular engines I'm not too familiar with. The cams are Kent GS2H. Power graph didn't particularly look odd in that respect, check the graph above and see what you think. It is curious however! Does seem to go quiet well considering its 'only' the power stated above, but definitely need to find more. I didn't look at the exhaust in detail. I'm told its a stock manifold into a powerflow system. Has a K&N filter power was no different with this on or not, so that's not causing a problem.
That is what I expect from the many engines that I have tested and shared with this forum at Garage Streamline that also have the same type of chassis rolls. In fact the peak 126lbft of torque @ 4800rpm aint to shabby and occurs much higher up compared the most STD engines. The curve is almost 16v like as a result. The torque is a bit 'wobbly' from 3500-4500 suggesting that you many have some room to smoothen out the PCM tables in these areas compared to your baseline. The torque ramp off many be difficult to improve if the engine is on best torque fuelling and the spark angle, already been adjusted to MBT and the cam has already been sweeped through a series of positions. The cam choice and setting has improved engine VE at upper rpm as on a stock engine I would expect ~ 80lft at 6400rpm where as on yours you have just under 90lbft@ 6800 rpm. This characteristic was there before the mapping as seen in your baseline test. A link to what we have typically seen on 8v engines can be viewed here and a test demonstrating a STD GTI engine on digifant is shown below. Assuming both dynos were at a similar level of compensation on the ATC2 setting, I would say not a bad effort for an 8v PS Not sure what effect the exhaust would have on an engine of this spec TBH.
