TimZ

Thanks, Jon - you saved me from having to type all that. For the record, I never said anything to the effect that it wouldn't work. The firing order is just an issue with that design that makes it less than the ideal setup. Unless you change the firing order of the engine, the center carb is the only one that is going to see evenly spaced intake pulses, and that's just how it is. The point of this is that because the 1 and 3 carbs see event spacing that looks pretty similar to that of the two carb setup, you should be able to get a two carb setup to run pretty much the same with proper tuning. Perhaps the even event spacing of the middle carb with fewer events per rev helps more than the uneven spacing on the other two hurts, though. Does that mean it won't work? Nope. How much less than ideal is it? Apparently not that much. Do I really care that much? Nope. I was just pointing out a subtlety in the design.

There was a discussion some time ago about the triple SU setup, and a problem that was discussed was the fact that the firing order of the L-series doesn't work that well with it. Basically, the carbs see the following: Carb 1 sees the 1st and 5th cylinders in the firing sequence Carb 2 sees the 3rd and 6th cylinders in the firing sequence Carb 3 sees the 2nd and 4th cylinders in the firing sequence So, while the middle carb's events are evenly spaced, the outer two are only separated by 1 event with 3 events in between.

How have you plumbed the PCV lines? Your problem could also be blow-by from the engine.

Yes - have your machine shop get the proper dimensions. If you can't find a stroker crank, I'd still recommend going with the L24 rods - I found these in the buy/sell/trade: http://classifieds.hybridz.org/showproduct.php?product=3343&cat=17 (no affiliation - just saw the ad)

If you are going to the trouble of custom forged pistons, why not go to the L24 rods? For that matter, a stroker crank isn't that expensive if you are doing the custom pistons anyway... Also, it would be a very good idea to get an accurate measurement of your block's deck height (crank centerline to deck surface). After 20-30 years, it's really hard to say whether/how many times the deck has been resurfaced and/or align bored. Don't rely on the stock specs for this - they are more likely to be wrong than right at this point.

I agree with the rest, but I don't think it works this way. Even if you removed the ground electrode, the edge of the plug would be closer than the top of the piston at the point you would want to fire it.

I seriously doubt that the CSR pump can flow more than the stock mechanical pump.

Okay - so I was skeptical, but not so much that I wasn't going to try it... I think there was at least one "are you sure?" in there before the "OK".

Glad I could help, Tony - I'm happy to see that you found this thread! I think that the mods I did to the stock distributor took me about an hour to complete - so that was really an easy way to get the cam sensor function. The TEC3 only requires you to be within something like 40 degrees for the full sequential function to work, so the extra scatter from the distributor drive is irrelevant. The most time consuming part of this mod mostly involved taking care of the aesthetics - I tapped the hole for the vacuum advance dashpot for a 3/8" npt plug, and then I cut down a distributor cap and filled the holes with JB weld in order to make it like it was meant to be that way.

I just took a factory electronic distributor, locked down the mechanical and vacuum advance mechanisms, and ground off all but one of the teeth on the reluctor. The factory pickup works just fine with the TEC3.

Short answer on the injectors (I'm at work) - ~630 hp number given earlier would translate to around 740hp at the crank. So that agrees pretty well with the limit for six 77 lb/hr injectors. The 150lb/hr injectors are definitely more than I need - hopefully the fact that I can run full sequential will mitigate the idle issues. I'm also hoping to run them at a bit lower base pressure.

I'm not sure - I've never had that problem before... I don't know that blowthrough will necessarily result in higher EGTs, but it seems logical that it might - maybe from fuel/air mix continuing to burn in the manifold (?). I was kind of hoping maybe somebody has had some experience with this - we must have some V8 supercharger guys here, right? Hell, there are even a couple of superchaged L6s here, and I even know who he is...

Thanks Dave - I was hoping you would chime in. In my experience more advance means lower EGTs and less advance means higher EGTs, so I'm not sure what you mean there (longer burn should translate to more energy transferred to work, thus lower temps when the valve opens). The boost creep thing is pretty strange - it seems to be keeping the same characteristic regardless of PR - it had pretty much that same ramp rate with the boost controller turned off as is does now at 20psi. Just with different pressure offsets. I think you can kind of see this in the last HP plot, where the thin line reference is a previous run at lower boost.

Thanks for the input. The backpressure thing seems odd to me too, but it's the most obvious thing that has radically changed from my old setup. Well, that and the new EGT probe and probe location (well, not radically different, but different nonetheless). The main reason that I was suspecting the lower backpressure was that I suspect that I'm now past the "crossover" point, such that my exhaust manifold pressure is now lower than the intake manifold pressure. This could make things act significantly different from before - for instance there should no longer be any problems with exhaust gas reversion, and depending on how low the exhaust manifold pressure is, I could actually have 'blowthrough' instead, as is sometimes the problem with supercharged engines. I have not yet had an opportunity to measure the exhaust manifold pressure, but hopefully I'll be able to get to it soon. It's also certainly plausible that the new probe could be reading differently than the old one, although I would expect that this would mean that I always had the higher EGTs, and the old gauge just didn't register them properly (i.e., I suspect that the old gauge would have read too low, rather than the new gauge being too high). I've verifed that the timing is now correct, first by verifying true TDC and that the pointer is exactly at "0" degrees on the damper, and then by locking the timing down to a single value and verifying with a timing light. The thing that was most surprising to me was that the new, correct timing should be 4.5 degrees advanced from the old timing already (i.e. 0 degrees indicated on the old setup was really -4.5 degrees), and I still ended up with higher advance numbers than the old map by a fair margin. So far I'm pretty happy with the TEC3, aside from some small issues, like the latest firmware rev changes the idle controller algorithm to be backwards for a previously working GM IAC. They don't admit that this is the case, but it appears that it is - rewiring the IAC is the only way to get it to work for most. It is really nice to be able to run in full sequential mode, rather than the phased sequential mode that was the best available from the TEC2 - you can get acceptable idle performance from a much larger injector this way - I never would have dreamed of using 150lb/hr injectors with the TEC2. For the most part, the TEC3 sets up very similarly to the TEC2, so there wasn't much learning curve required there.

Sunoco 94 octane pump gas. No water or meth injection, no nitrous. The amient temps were a bit low - ~50degF.

It's a Gt4294R - 94mm compressor inlet, 1.15AR tubine housing, 84mm turbine impeller

It's a GForce T5, built into a customized datsun t5 form factor (Datsun t5 bellhousing, Ford WC T5 gear case, modified Datsun T5 tailshaft housing). R230 rearend with a KAAZ limited slip and all of Ross Corrigan's finest pieces connecting it to the wheels. I have to say I'm as (happily) surprised as anyone.. James Thagard talked me into the turbo, but I was skeptical - it just seemed too optimistic. It does take it a bit longer to come on, but when it does, DAMN! As far as mods - all of the above. I've been refining this engine for years, now - I bought the car in 1980 - it's the same block that came with the car. Okay, so just about everything else has changed... Again - take the numbers with a grain of salt until I can get the bigger injectors up and running and some dyno time, but this is looking pretty encouraging.

That's a really nice example of the Countach. IMHO, they looked much better before they got all crapped up with wings.

Agreed - I've been to a few of their autoXs, and they do a great job. I've noticed that they seem to prefer shorter, tighter courses - go figure . There is a really nice older GTV like the one posted first in this thread on the next block over from me.

Thanks Yasin - it's a measurement derived from 3rd gear WOT acceleration, so it's rwhp. I generally use it to gauge my progress more than absolute power measurement, so that's why I said "take it with a grain of salt". That said, the numbers that it comes up with have been pretty surprisingly consistent with actual dyno measurements. Just as a double-check, I also back-calculated the power level that would result from my injectors going static, given the BSFC that I calculated from my last dyno pull, and that number came out in the same ballpark (actually a little higher, depending on what drivetrain loss number you pick- I used 15%) The new EGT probe is located in the spacer between the header and the turbine housing, so it's directly in the flow path. The old probe was mounted in the header at the transition point between the WG and turbo flanges. I just moved it because the old location proved to not be particularly serviceable.

B. Front mounted v6, rear transaxle in a DeDion rear suspension.

and speaking of Alfas - I still have a soft spot for the GTV6... (I linked this from http://www.alfagtv6.com) I had a GTV6 Balocco SE back in the 80's. What a heartbreaker. Interesting looks (I won't say "beautiful", but it sure didn't look like anything else around at the time), great ride and handling. But the transaxle was fragile as hell (synchros made of cheese, apparently), and it seemed like every time I drove it, something worth at least $200 broke. I've been thinking this would be a great candidate for an SR20 swap, along with a suitable transaxle...

Okay, also linked from another site (http://www.miurasv.com), but... I can't believe that nobody has mentioned the Miura yet!!! Simply the most beautiful car ever built.

Well, it looks like the new turbo has some serious potential... (take the HP number with a grain of salt, but it's been surprisingly close so far...) Some Details: The reference plot here (thin line) was a run with the old setup (TEC2, T64, o-trim .84AR). Notice the substantially lower boost levels with the new setup. While I had the car down for this rework, I double checked the TDC marks on the crank damper, and found that I had been using the wrong timing mark on the BHJ damper. I corrected this, so the timing is now ~4.5 degrees advanced from where it was (i.e., 0 degrees indicated on the old setup was really -4.5 degrees. Now 0 degrees is 0 degrees) A couple of things that are perplexing me... I'm seeing REALLY high EGTs - on the run above, I exceeded 1700 degF My AFRs are dead nuts on 12:1 on boost - I'm going to try going to 11.5:1. I've been adding in timing, and the temps have come down to the low 1600's , but it seems like I've got an awful lot of advance now... The reference plot here is the run in the first pic. ...on this run I'm seeing 30 degrees advance at 17 psi, which seems like alot. I've not heard much as far as detonation yet, but this is making me really nervous. This turbo has radically less backpressure than the old T64 - could that be causing the higher temps and allowing/requiring the increased timing? I'm a bit confused at this, seeing as how the rest of the setup (engine, cam, intake) is the same as before. I'm also using the new Defi gauges, so it could be apples and oranges comparing to the old VDO gauge. Both probes measured at the turbine inlet, but the new probe is oriented a bit differently -more directly in the flow path. Another weird thing - I seem to be getting some boost creep now, which never happened before - this is a 60mm wastegate with it's own 2.25" downpipe. Not sure what to make of that, either. When boost first stabilizes, I seem to be at around 16psi, then it creeps to 19psi by 7000rpm. It would be really nice to be able to get beyond this EGT thing and see what it does at 24psi... Went back out again the next day and backed the timing off a bit and added fuel. This seemed to be helping, so I turned the wick up a bit... I think it helps somewhat at higher boost levels, simply because you get there quicker and things don't have as much time to heat up. Soooooo... Next problem: ...looks like I just ran out of injector (72lb/hr, with a base pressure of 50psi, so they were flowing 77lb/hr). James just sent me some bigger (150lb/hr) injectors - looks like I'm gonna have to break them out sooner than I thought.

What makes you sure that this was due to the N42 head? How old was the gasket? Had you re-torqued it recently? What head bolts were you using?