Wow, been quite a while since I updated this thread. Since the 2084cc motor is done and in use (link in sig), time to get back here and start updating the build.
I have so many updates I don't really even know where to start...I guess the most recent update would have been the new fuel system. The new motor has been run exclusively on E85, so all parts are purchased with that in mind. That might change as I continue to drive it and ultimately get it back to daily driver status in the warmer months, but currently, it’s just a racecar. Back story: As I was getting a few pulls on the new motor the other week, I noticed that it would rev up a bit and before I would ever get to the max RPM range, it would just start cutting out. Went home, pulled up the logs, and noticed my full pressure was going down down down every time I went into boost. I was Autotuning at the time, and the VE table was getting bigger and bigger, trying to dump more and more fuel into the system to hit my AFR targets. Needless to say, it eventually went lean and hit my AFR safety stop, hence the cutting out in the upper RPM range. My injector duty cycle was something dumb like 98%, and I just thought there was no way the 82lbs injectors weren't able to keep up...looking further at the log, my fuel pressure went down to something like 24psi. Yikes. The next day I tested the FPR with a bike pump and ran a log. I put 20psi of air on the regulator and sure enough the pressure rose from ~40psi (motor off, pump on) to ~60psi. So the fuel pressure regulator was functioning appropriately (1:1 rate as advertised), so that means my pump or filter was acting up. So time to replace those and redo my fuel routing a little bit. Previously I had the filter before the pump. Per a couple articles I read, pumps are better at pushing fuel, and not pulling it, so that logically made me think the pump should be pushing fuel through the filter, and not sucking it through. Anyway, I got a new Bosch 200 (which now supersedes the ever popular 044), and a new 10 micron SS fuel filter pre injectors to be used for the E85 I am running. This new set up replaced my Airtex amazon pump (was good for me until it wasn’t), and some off the shelf filter from Autozone (again, it worked until it didn’t). Being the procrastinator that I am, the new parts were delivered just a couple days before the most recent drag race day. So I was left with a few days to find the appropriate fittings and hoses required to plumb it all up. It was a mad scramble the day before the races to get all the fittings and hose fitted, fix a single leak, and then get a few minutes of tuning in before I had to put the Beetle on the trailer for the races the next day. Jim came through big for me as usual, and hooked me up with the banjo fitting that goes on the 044/200 pump feed side, and also tap the propriety weird ass adapter fitting that goes on the inlet side to allow me use of an NTP 1/8 fitting.
With the new system in place, Dad played co-pilot and manned the laptop while we did some quick autotuning and got a couple pulls to see if the new pump and filter did the trick. Sure enough they did, and fuel pressure was rising accordingly with boost…but I couldn’t quite tune the top end because my AFR safety system was kicking in again, but this time because the AFR was pig rich running on the table with huge VE values. Oh well…I’ll fix it at the track.
Next morning, got to the track, unloaded it and got the first run in. Ran a 15.69 @ 95mph, autotune set on “Easy”. Still hit a safety system, and I thought it was the AFR safety, but it wasn’t till my 4th run of the day that I found out I had a Boost cut off on at 225KPA. Silly me. Either way, my goal of every race day (this was my third event) has always been to “do better than last time”. So needless to say, cutting off almost 2 seconds from my run with the 1776T a year prior was better…goal met.
Now it was time to figure out a little more with this new motor, and see if I could actually improve my runs from the previous 30 or so minutes of total tuning that I had done. Like I mentioned, the VE table that I ran for some of the day were super fat, and as I tried to lean it out from 9:1 all the way to 11.5:1, it ran fastest at the ~10.8:1 tune. With this tune, I ran a 14.1 @100 mph, which has been my best run to date (I’m VW66 in the pic below). Post race day, I have come to find out after hours of reading recently that E85 is a completely different beast, and I think it has much more to give me. I’m not going to go into too much detail until I have had some time to get some miles on the car and test my new theories, but I plan to tune the entire boost areas a little richer (10.8:1), and with a little more progressive timing further into RPM (low 30’s or until it doesn’t give me diminishing returns).
All of this information has to be precursored with the fact that I wasn’t using any launch control, and I was pretty much rolling off the line so I didn’t bust up my stock transaxle. Once I get my two-step sorted and can consistently launch at the same RPM, I will be able to compare my timing and VE tunes to one another.
So with all that said, it was a fantastic race day, nothing broke, and I met my goal of doing better than last time (by 3 seconds!). I know I have a TON of work to do to get this car in line, and upgrading the transaxle is pretty much holding the motor back from hitting much lower than a 13 second run. All in due time though. New motor is awesome, and I’m having a pretty good time messing around with it. Cant wait till September for the next drag day!
FYI, Green bug in the picture there ran 10.5’s all day. Gonna be a little bit before I can catch up to him.
Painful
