Yep I know, Peter. I understand how it works. That doesn't mean sticking to the same AFR's that's done on 100% gasoline is the way to go when doing these kinds of blends.

B

How much excess over stoich you need is up to your situation and findings.

The number relations are nothing more than peoples *understanding* of this excess ratio to stoich *ones that have an instant meaning and effect on the brain* :)

Well hopefully once I put this thing down on the roller I can make more sense of it all. I think once there's a shift in fuel type all of the rules change. That's what makes it interesting, right?

B

Feb 5 '09 Update
 

Howdy, folks. Today was 71*F here. Cruising IAT's were 116-118*F. I was able to do only a couple runs today but they're not much to speak of other than the EGT's remaining lower and flattening off a bit more. I did, however, notice something odd on the 2nd datalog during a 3rd gear pull: At one point I saw an 11ms injection time. I can't find anything else in the datalog that would otherwise suggest why the ECU would do that. I don't recall feeling any hiccup in the car, either. Car runs fantastic.

I've got plans to get a Hall trigger setup done as well as get some time on the dyno. I'd like some more data on the correlation of EGT's vs. AFR's. As it stands now, I'm keeping them in the low to mid 10's. I'm running 30% methanol and 70% gasoline at 15+psi still (M30 as I call it). Today was the first day I've seen IAT's crest and get over 100*F while in boost (target of 23-24psi). At 22psi, they plateau'd at 98-99*F. At 2324, they were 100-102*F. 30*F above ambient at 1.6bar of boost without an intercooler ain't too shabby, I must say. I'm curious how these temps will remain when we have warmer days here.

I also advanced the spark a bit to 9-10* Lead with a 9-10* split at 23psi. My on boost EGT's with this much alcohol are sitting around 1630-1670*F from 4500rpm onwards, mostly. My AFR's aren't perfectly flat across the board so I think the variances are coming from that. The hottest I saw was 1700*F at the top of my 3rd gear run. Otherwise it's hanging in the mid-upper 1600's mostly. Doing the change to 5% more alcohol made a pretty significant difference.

First datalog was 4th gear. I tried stretching it out some but the car is just too dang fast to do this by myself. 2nd was 3rd gear.

BDCHA37 4th gear

http://bdc.cyberosity.com/d/14226-1/bdcha37-1.jpg

http://bdc.cyberosity.com/d/14228-1/bdcha37-2.jpg

http://bdc.cyberosity.com/d/14230-1/bdcha37-3.jpg

http://bdc.cyberosity.com/d/14232-1/bdcha37-4.jpg



BDCHA38 3rd gear

http://bdc.cyberosity.com/d/14234-1/bdcha38-1.jpg

http://bdc.cyberosity.com/d/14236-1/bdcha38-2.jpg

http://bdc.cyberosity.com/d/14238-1/bdcha38-3.jpg

I wish the PFC made logs like that. I like how the PFC Plays back logs, but the haltech logs make it very handy showing to other people.

Brian, is there a reason you don't want to try a small mixture of water mixed with the methanol? I know the alcohol is working very well for you, but there is still always that "what if". Like what if the mixed ratio caused AIT's to remain the same but EGT's lowered? Or what if both EGT and AIT's stayed the same, then you can use half as much meth. (cost) Just tryin to put a lil bug in your ear. Either way you have accomplished quite a bit, with the logs to prove it. In several pages I haven't seen even one person make mention of how bad of an idea it was to remove that intercooler. Now that I have my Preturbo WI kit installed I might try some experimenting with the intercooler bypassed. We'll see.

-Brent V

I might give it a try. Doesn't hurt to try I suppose. I think I'm close to half a gal of alcohol in the cell anyways. I can pop half-gallon of distilled water in and see what happens.

B

That's the spirit!

You're probably already going to do this, but when you give it a try start at the lower boost settings first to make sure the AFRs, and AIT's are still in check. You seem cautious about things like this, so this is just a small reminder so that if you go out and run lean on 23 psi I'm relieved of any guilt from suggesting the water and you breaking something. lol

I Look forwards to the result.

I also think that it wouldnt hurt to try a little water in it, but at the same time I like the fact of trying to get as perfect as possible with only Alcohol and IMPORTANT trying to test one single change at a time, before adding water into the equation. I know it is time consumig but the problem is that when you change 2 things at once, then you never know exactly which of the 2 did play the biggest role on the changes you see.
Anyway, I am really happy to see all the interesting evolution of this setup in your logs :)
Keep it up Brian.
Leo

Just ran some numbers about IAT's before and after. Found this website that does the calculation for compressor discharge temperature based on inlet temperature, turbo efficiency range, and psig (pressure on the boost gauge).

http://www.stealth316.com/2-turbotemp.htm

Using this compressor map: http://www.lextreme.com/forums/showthread.php?t=1714 as well as a 71*F ambient temperature for inlet temp, 24psi, and efficiency of 75%, the outlet temperatures are calculating to right at 300*F. That means the alcohol in this hot-air pipe is peeling about 200*F off that.

B

Edit: The boost I'm running right now (23-24psi) is a Pressure Ratio of 2.60 to 2.64:1 on the compressor map. If I go to 25lbs, it'll be right at 2.70:1. According to that map, that's about 62-66lbs/min of output airflow.

66 lbs/min* 14.471= 955 CFM/1.92= 497 rear wheel rotary hp.

Update
 

Hey folks, got an update. I cracked the rear plate on the motor a few days ago. Atleast it happened with a little glory as I was roasting the rear wheels in 2nd gear while banging off the rev limiter (8200rpm spark cut) at about 60-65mph. I had my wife in the car and was showing her how powerful the car had gotten since the new setup.

I've been trying to figure it out the past few days why it happened and I think I know why. I think it's also the same reason why it happened on the front iron a couple years ago at the same RPM. I realized that the trigger harness I've got (Haltech E6K) is not shielded. My supporting reasons for this are two-fold:

1) When I first installed the E6K back in March 2000, I originally used a pair of those MSD 8509 "signal stabilizers" (aka external reluctors) for the trigger input. I'd cut into the trigger harness on the ECU end where the MSD's were located. I raced the car during that year and the next year quite a bit at the 1/8mi track and never had an issue with high RPM anything. Around 2002, when the car had some problems and wasn't being driven much, I'd swapped back over to the internal reluctor setup and removed the MSD's. I never re-shielded the trigger harness. It's not been touched since. The car was never driven under high loads due to not having an adequate intercooler and other reasons and was only rev'd up for it in summer '06 when I started fooling with alcohol. I think the unshielded trigger problem surfaced during this time.

2) Per reason #1, high RPM noise being spat out unto the trigger harness, goofing the ECU up. There was one time a couple weeks ago that I swore I could've heard it rattle-can knock up around 7krpm that just came out of nowhere.

3) Possible crossfire on the plug wires as I've got a couple of them tied off in places (together) to keep them away from the SS-braided lines I have all over the place on the driver's side of the motor

I'll get it out and torn down probably within a week or two and post up some photos. I don't plan on changing much other than the front and rear irons but I am having some reinforcement work done on the block. This is the second S4-style plate I've cracked and it's not happening again. I figure if I'm doing this goofy kind of experimenting where every I has to be dotted and every T crossed then I need to have everything in A+ shape on the whole setup.

B

Dayum, never good news. I'm no stranger to failures so you know I feel your pain :lol:

Cracked at the dowel, or another spot?

Yeah Joe, on the back plate, upper dowel run. It's not that big of a deal. It'll give me an opportunity to do some of the stuff I didn't do last time due to my impatience in wanting to get the car running so it's no sweat.

Part of the things I wanna do is switch over to the Haltech's Hall sensor setup for the trigger and ditch the crank angle sensor.

Good to hear, you know my stance on the stock crank sensor ;)

That's always a little embarrassing to break something while showing off. At least it was your wife and not just some girl you're trying to impress lol.

Are the FD's prone to this kind of failure? Since I'll be pushing close to 500 hp as well I'm wondering what I should be prepared for.

ya bdc has told me time and time again he doesnt click factory CAS.
now im starting to get worried bout that.

Engine detonation will break anything. (plates, smash seals, dent rotors) < any one or all of these symptoms.

Solve that and you will have a reliable engine.

Never ever had a problem, 600rwhp and counting ;)

Detonation and the causes of it are not inherent to the early distributor types CAS or the later versions that do away with this, well not from what I have seen anyway.

NO

You need to understand detonation is a result of a few things.

Inherent Engine strength is not an issue in a FD but causes of engine detonation be it (electronic, wrong spark timing programmed or accidentally triggered) or combustion instability (most common, wrong fuel mixture, not enough fuel richness, too low a fuel octane rating etc) account for a whole shipping container of FAILED engines :)

+1 from me for once, Peter.

B

ah crap, you going to throw in a couple extra dowel pins? :D doooo iiiiiiit!

Something like that but not exactly. ;)

B

Open your log with Excel--same result, without the 90s MS-DOS look.

must be making some power now man!!!

damn B, i thought you woulda ditched the CAS last time you cracked the plate.