This was a long pull through 3rd and 4th and partially into 5th. 14psi with ~11.4:1 AFR. Intake temp was pretty high, but that was after boosting like a mad man for about 10 minutes straight before this pull. My main concern now is timing, what would be more ideal here? I'm looking to try higher boost soon (18+) and I'm curious if this timing will cut it. This was with stock ignition. Also what would be an ideal AFR for 18+psi. My wideband only reads down to 11:1, and I'm pretty sure I should be running somewhere in the 10-11:1 range for that kind of boost, and 11-12:1 range with 14-15psi. I tried to seperate the log fields with spaces but the forum doesn't seem to notice more than 1 space in a row.


RPM, Timing, IAT, O2 , STFT
2966.0, 36.0, 133.0, 0.53,-19.53
2971.0, 36.0, 133.0, 0.04,-7.81
3129.0, 14.0, 133.0, 0.89,0.0
3376.0, 18.0, 133.0, 0.93,0.0
3695.0, 19.0, 133.0, 0.93,0.0
4094.0, 18.0, 131.0, 0.91,0.0
4496.0, 16.0, 131.0, 0.91,0.0
4848.0, 15.0, 129.0, 0.93,0.0
5153.0, 14.0, 129.0, 0.94,0.0
5669.0, 16.0, 129.0, 0.94,0.0
5991.0, 20.0, 131.0, 0.96,0.0
6061.0, 20.0, 131.0, 0.96,0.0
4825.0, 29.0, 131.0, 0.91,0.0
5000.0, 15.0, 136.0, 0.94,0.0
5184.0, 16.0, 136.0, 0.94,0.0
5453.0, 17.0, 136.0, 0.96,0.0
5614.0, 18.0, 140.0, 0.96,0.0
5754.0, 20.0, 140.0, 0.96,0.0
5914.0, 20.0, 140.0, 0.96,0.0
6063.0, 20.0, 140.0, 0.96,0.0
5205.0, 21.0, 145.0, 0.75,0.0
4770.0, 38.0, 145.0, 0.79,0.0
4902.0, 15.0, 145.0, 0.94,0.0
4975.0, 14.0, 147.0, 0.94,0.0
5066.0, 15.0, 147.0, 0.94,0.0
5128.0, 15.0, 147.0, 0.94,0.0
5045.0, 15.0, 147.0, 0.73,0.0
4971.0, 25.0, 149.0, 0.02,0.0
4843.0, 27.0, 149.0, 0.02,0.0
4735.0, 28.0, 149.0, 0.02,0.0
4669.0, 29.0, 149.0, 0.02,0.0
4602.0, 29.0, 149.0, 0.02,0.0

Also EGT's were good, slowly rising over 1500 at the end of that pull which got pretty well into 5th gear.

Log a single 3rd (or 4th) pull from around 2500 rpm, don't log IAT during the run, just note it before hand, should give you much more data.

The only thing really to comment on from that log is get your intake temp down! Tis a distroyer of engines. If you get your temp down you could increase your timing at peak torque, and get some more ponies.

Is your upper IC pipe aluminum or steel? Do your temps go that high from boost, or from underhood temp? If it's the first, you need to get a more efficient IC, if it's the second, you need to evacuate some underhood heat.

The pipes are all alluminum, and they get really hot. I'm pretty sure its from underhood heat. I've felt the IC after long pulls and it seemed pretty good. That was also the first time I've ever seen temps over 130º. I'll do more logging tommorow. Is there any (simple) way to vent underhood heat?

The easiest way to get rid of lots of underhood heat is to get a turbo insulation kit (I got a DEI one from summit), they come with wrap for your downpipe too. You could make a bolt on heat shield for your turbo manifold (cheap), or get it JET-HOT coated (a little $) for 50% reduction from manifold heat.

As far as venting it, remove the weatherstripping from the front and rear of the hood if you haven't already. Make some vents in your hood, preferably in the design of backwards scoops (like cowl hoods) to suck cold air from underneith the car out, along w/ the hot engine air. Don't ram more air underneith the car (heat wants to rise and air under the car causes less downforce).

Some people put spacers (or big fender washers) at the rear of their hood to prop it up, although this doesn't do a whole lot because the base of the hood is about the highest pressure zone on the car (air doesn't like to escape at speed very well here).

Again though, I would start by getting the turbo insulation kit, it reduced my IAT a whole 30*F!!! Unbelievable, I know. My upper IC pipe was getting super heated and acting like a inter-heater after my well working inter-cooler.

Your timing advance looks damn near dead on with what mine had done when i ran the stock ECU. Timing in boost starting around 14-17 degrees, then slowly going up to 20 degrees or so past 6k up to redline. Everything seems fine there. Your A/F is good too where its at. I've done a LOT of tuning for around 15 psi on the S16g turbo, and i've come to the conclusion that 15 psi is getting really close to maxing out 93 octane fuel, with proper timing advance. I have the megasquirt timing tables set for advance almost where the stock ECU is at timing wise for that boost pressure. I run around 17 degrees at 15 psi, slowly going up to 20 near redline. Any more timing then this, it can knock slightly. Any less than this, EGT's get pretty hot up to 1600 degrees. This says that we could use a bit more timing for that boost pressure, but we cant becuase it will detonate. 93 octane fuel is barely cutting it here. Also, my intake temps are around 100 degrees at that boost pressure.

Personally, I would be very, very careful of running 18 psi on pump gas, esp with your intake temps as hot as they are. If you can get those down to 100 or around there, that would help. Coolant temps in the 180's will help as well(get a 180 T-stat, and run the pass fan on all the time). Since you dont have any way to really control your timing advance accurately, to run 18 psi, I would increase your fuel octane. It may only take some mixing of 92-93 with some 100 unleaded to get the job done safely. I'd say and octane rating of 96-97 would be fine for 18-20 psi. Thats just an educated guess though.

Originally posted by sike
Is there any (simple) way to vent underhood heat?

Spacers (and longer bolts)on the hood bolts to hinges raising the back of the hood causing an extractor affect = test.


I figure since I cant stop fixing the damn thing, I'll just create more problems to work on. :) The stock pile has begun. Parts PArts PARts PARTs PARTS!!!
I'm a novice listen to what I say and make your own conclusion. If I'm wrong tell me and I will learn. Thanks be to the 2gnt Gods may they grant me turbo and fruits of the Earth. Amen.

Thanks, I think I'm going to stick around under 16 until I get MS. Unless I decide to run some race gas and see what I can pull off. HS_elrod what was the "= test"? I'd like to try the spacer idea and see what I can get. I'm also going to get some heat insulation for the turbo.

I was just stating that you can open up the gap between hood and car to allow more air to escape from the engine bay in an attempt to lessen the intake charge temp. never tried it before but i think it works. "=test" means that if that works then you def need to look at engine bay temp and if it doesnt work you def need to take a closer look at that intercooler.

If I say "=test" that just means try it to illiminate a possible cause(troubleshooting lingo)

Blah

I figure since I cant stop fixing the damn thing, I'll just create more problems to work on. :) The stock pile has begun. Parts PArts PARts PARTs PARTS!!!
I'm a novice listen to what I say and make your own conclusion. If I'm wrong tell me and I will learn. Thanks be to the 2gnt Gods may they grant me turbo and fruits of the Earth. Amen.

Lol. I got you elrod. I will give the raising the hood a try tommorow. I wrapped my DP today and removed the weather strip, turbo insulation on the way. I will wrap the manifold with the heat wrap that comes with the "kit". Max temp today was 136 @ around 5000rpm in 5th gear pulling from 2500rpm in 3rd. It was also cooler tonight. I appreciate the responses and help guys.

New log with just timing, much faster responses as WickedeESi said. Seems a little funky(lower, more curved) compaired to last log. 3rd & 4th pull, around 116º intake temp at the end of it.

RPM, Timing
3rd gear:
2503.0, 24.0
2576.0, 24.0
2635.0, 24.0
2613.0, 12.0
2720.0, 12.0
2815.0, 14.0
2962.0, 15.0
3075.0, 17.0
3224.0, 18.0
3369.0, 20.0
3564.0, 20.0
3765.0, 20.0
3962.0, 18.0
4205.0, 15.0
4408.0, 14.0
4566.0, 13.0
4759.0, 13.0
4955.0, 12.0
5103.0, 13.0
5274.0, 14.0
5447.0, 15.0
5622.0, 16.0
5780.0, 18.0
5542.0, 19.0

4th gear start:
4476.0, 17.0
4529.0, 16.0
4608.0, 15.0
4714.0, 15.0
4766.0, 13.0
4896.0, 13.0
4939.0, 13.0
5062.0, 13.0
5097.0, 13.0
5218.0, 14.0
5261.0, 15.0
5430.0, 15.0

Hmm... I'm willing to bet your knock sensor is picking something up at peak torque and when the boost is kicking on. I don't think it should get that low...ever.

Either your knock sensor is exagerating/picking up a false reading, or your actually going real lean. I'm willing to bet it's the first, but make sure.

I will log again and see if i get the same results in the next hour or so. i have a slight knock at idle but i do not hear it when driving, perhaps that is the cause. also I've taken out my knock sensor before and did not torque it to specs, i'm understanding that could be a problem also.

If you KNOW your fuel supply is good, unplug the knock sensor and log it. I don't use mine because my solid mounts making everything vibrate would cause the bastard to pull timing all over the place, but particularly at peak torque.

Can I pick up a 180º thermostat at any parts store? What do I ask for?

The turbo insulation came in today, I'm going to wrap it and the rest of my downpipe tommorow before I go to the track... AGAIN. I best hit over 100mph or I am burning it to the ground right there at the time sheet booth.

I've got a few more questions I'll just post here, if someone wouldn't mind reviewing:

1) I'm running stock head @ 15psi. I've decided against trying 15+ on 93. How effective would redoing the entire head be for me right now?

2) Exhaust. Off my turbo I have 2.5" pipe, going to about 2' of 2.25" pipe then going to 2.5"(press bent), test-pipe back. Is this enough?

On the timing and octane note: We have a local stations with 100oct. I may occasionally try this and bump up the boost, maybe even tommorow for the track.