shauer

I just checked over here and saw your post for the caravan. I'm not going to be able to join you this year. I'm heading out Wednesday taking 90, 71, and 75 down to Knoxville TN. Staying over night there and then driving 129 into NC Thursday morning. I'm staying at the Hawthorne so I'm sure I'll see you when you arrive. - Steve

You are correct but it's not that simple. VEAL does take EGO correction into account but it is far from perfect. There are time lags involved. VEAL is up on the PC and needs to get its data via the serial connection which introduces a time delay (although not a large one). On top of that, VEAL has a time lag table built in that tries to account for the delay in the EGO reading based on MAP and RPM. This means that VEAL is most likely looking at a different point in time than the EGO correction algorithm with regards to EGO data. As far as I know, EGO correction does not have a time compensation for the delay in sensor response. Now, the closed loop EGO control has different delays built into it with regards to sampling interval and integration time. This means that the EGO correction is normally in a state of transition as well. If the closed loop EGO correction is not dialed in correctly or the VE table is way off you will get very large EGO correction values that change very quickly. VEAL will take these corrections into account but if you are accelerating it is likely that VEAL and EGO correction are not going to be working on the same VE cell. This is why I recommend establishing a base tune using one algorithm at a time. What I have found is that VEAL and EGO correction trying to solve the same problem at the same time with different gains and response times causes poor results with VE table correction especially when RPM or load is changing relatively quickly. I apologize for getting the thread off track with talk about VEAL and EGO, it's just that I have experienced several folks getting confusing results because of this. - Steve

Actually, EGO correction and VEAL are completely different features and do not rely on each other. However, having poor VE table values, bad accel enrichment settings, and having closed loop EGO enabled as well as VEAL is a recipe for poor results all the way around. What I do is turn off EGO correction completely and get a baseline VE table using VEAL. If your wideband O2 gauge is accurate and providing good data then I have found that VEAL does not care what the target AFR is set to. I suspect that the recommendation around a 14.7:1 AFR target with VEAL has more to do with other factors such as incorrect accel enrichment and closed loop EGO control confusing things. I use VEAL to tune my car with a range of AFR targets from 12.5:1 to 16:1 and it does a great job. One consideration is to set up the tune so you understand where the correction is coming from and only use one form of correction at a time. I turn off closed loop EGO control and get my VE table roughed-in with VEAL. I do progressive drives with VEAL setting the change control on VEAL to "harder" settings so that it makes smaller and smaller corrections until I converge on a VE table that is within a few percent of ideal. Then I go back and get my accel enrichment dialed in so that I do not go over rich or over lean. Only then do I turn on closed loop EGO correction. You do no want closed loop EGO correction fighting with VEAL and both getting thrown off my bad accel enrichment settings. The different algorithms end up chasing their tails and you get confusing, contradictory results. In summary, this is what has worked best for me on several cars and tunes: 1. Turn off EGO correction 2. Use VEAL with progressively more conservative settings to get a good VE table 3. Use log data to tune accel enrichment correctly 4. Turn on EGO control. You should not need more than +/- 5% control authority on the EGO control if your VE table and accel enrichment are correct. - Steve

No problem. shauer at rochester dot rr dot com - Steve

Are you using tuner studio for your tuning application? It is entirely possible that the label on the Y axis for the VE table may not change wording when selecting AN mode. You can easily check if you have enabled AN mode by simply moving the throttle and seeing if the active bin on the VE table moves up and down with the throttle. Load the tune file that you think is set to AN, don't actually start the engine but turn it on so MS is up and running. The active VE bin should be the min-rpm column and move up and down with the throttle. On my MS3x setup with TS, the Y axis is always called "fuel load" which is a nice generic label that I think the developers selected to simplify needing to change labels with different settings. If I was in your situation, I would skip the blended tuning step and go directly to the ITB load tuning. ITB mode uses only 1 VE table and not 2 so it is simpler to tune. The VEAL feature of tuner studio is also compatible with ITB mode but not with blended since VEAL does not understand using 2 VE tables together for tuning. I would complete the data log analysis you are doing with your logs from your SD tune to characterize the throttles. I would then enter the throttle curve in the ITB mode setup and simply start with your SD VE table as an initial set of values for ITB mode. Your SD table should be good enough to get your engine started and idling. I would then use the VE analyze live (VEAL) feature on tuner studio and have TS auto-tune the remainder of you VE table. I have done this several times where I get the engine warm and idling and then run the engine through the RPM range in the garage using VEAL to rough-out the VE table. I then start driving the car carefully, starting with low-load and low-RPM and let VEAL do its thing to establish the VE table. I then carefully increase load and RPM while driving until I have most of the VE table roughed out using VEAL. I normally do this across several test drives with a little manual editing of the VE table in between runs. I can have a VE table within about +/- 10% this way with a few test drives using VEAL to do the majority of the work. This is really not possible with the dual table blended tune. Sorry I missed your email. I'm sure i got it but it most likely got lost in my preparations for the Vintage at Saratoga. I'll go back and look for it. - Steve

What MS firmware are you currently running and what tuning application? AN should have TPS on the Y axis and RPM on the X axis of the VE table. The Y axis should be TPS (either as 0-255 or in % depending on version of MS) You need to set the primary control algorithm to AN but the exact wording of that option and the location of where to do it varies depending upon the version/generation of MS as well as the tuning application used. You say you are planning on transitioning to blended tuning, which method are you planning on using for your primary table (SD or AN)? I have done both and both work well, it really comes down to personal preference or what you have started with. It is possible to transition from SD to blended SD/AN without the need to come up with a full AN table first if you already have a good SD table. http://77e21.info/mstuning_blendedansd.htm - Steve

I am looking for a driver's side seat back adjuster for a late style E21 Recaro seat. My seat is from a '83 but I think the adjuster from a '81-'83 may fit. Here are a couple pictures of the adjuster I am talking about. I need the actual adjuster mechanism, not the plastic covers. Must be in good working condition. - Steve

The E30 unit is not a bad idea, I'll look into it as a possible option. I agree with the invasive comment. I need to mount it under the dash to pull on the gas pedal lever since I cannot ever have slack in my main throttle cable. Everything will be under the dash and can be pulled if it does not work out. No extra holes through firewall. My entire engine and Megasquirt harness is hand-made custom anyways, adding a few new wires to it is not a big deal to me. Thanks for the E30 idea. - Steve

Before next year's drive down to NC for "The Vintage" in May, I want to add cruise control. I have been looking at this unit from Rostra: http://www.rostra.com/products/unive...by-rostra.html Does anyone have some first-hand experience with this unit or another fully electronic cruise control unit? Any information would be helpful. I need fully electronic since I basically have no engine vacuum due to my ITBs... I have seen of few of your cars at The Vintage that had cruise so I'm hoping I can get some information. Thanks! - Steve

I'm not quite sure if I understand the question but I'll give it a shot. I cannot quantify the difference partly because I have never personally used the e-21 intake for EFI. I went from k-jet to dual Weber DCOE to EFI with ITBs. The e-21 intake is not really the best choice for EFI anyways. The simplest solution is the E30 318i intake complete with injectors and fuel rail. It makes a very nice daily-driver setup that can handle moderate engine modifications. The difference between a common plenum intake and multi butterfly is the same for EFI as it is for going to dual side-draft carbs. You can get faster throttle response and better high-RPM performance. ITBs are however much more difficult to tune correctly than a common plenum. Hope your answer is in there somewhere. - Steve

That is a great book, I read it years ago and tuned intake theory works regardless of if the car is a "street" or "track" car in the same way that tuned exhaust theory works. I can speak from 1st hand experience that swapping 50mm air horns for the 320i curved intake runners increased volumetric efficiency on my engine by 20% in the 3500 - 4500 RPM range while having a negative effect over 6000 RPM. This data is based on the change in my megasquirt VE fuel table before and after the change. Unless you are planning on driving your car at 7000 RPM all day long, you want to go with an intake runner length in the 15 - 19 inch range as measured from the center of the intake valve to the end of the air horn. - Steve

Either solution will work equally well. It really comes down to personal preference at this point. A distributor modified to produce a single pulse or a sensor through the timing cover will both work. I personally did not like the distributor idea, I thought the timing cover method was a cleaner solution. Again, just my own personal opinion. - Steve

True, on a megasquirt sequential setup the crank trigger is used for all timing (fuel and spark). All you need from the cam is a single position pulse to qualify the next missing crank tooth as the missing tooth prior to cylinder #1 TDC. As long as the cam position pulse occurs prior to the crank wheel missing tooth, the exact cam timing will not matter. - Steve