Need help safely upping boost

[JayRolla]

The fuel pump rewire has to be done by now right? Just joking, im really want to now how much extra fuel it puts in. Im going to do it if it allows you to run more boost. Keep me informed. COOL

 

[kenamond]

The fuel pump rewire has to be done by now right? Just joking, im really want to now how much extra fuel it puts in. Im going to do it if it allows you to run more boost. Keep me informed. COOL

I did the rewire, but I haven't had a chance to log another pull. It's cooler out now, so I'd expect to lean out at 15psi above 6200rpm without the rewire, so maybe this will tell you something if I don't lean out now.

If you're not hitting fuel cut but you're leaning out, do the rewire (unless you're going to upgrade your fuel system soon). If you're hitting fuel cut, the rewire won't help.

I suppose that if you're putting in a larger pump, you need to run 10ga wire to it anyway (can someone confirm - this is just my guess), so you probably need to do all of that anyway.

 

[hottboost]

If you rewire the pump it will give you a constant voltage to the pump and let it run a little less noisy. It is not required but a good idea. If you are close to maxing out the 190 and the voltage drops you could get in a lean situation.

 

[kenamond]

If you rewire the pump it will give you a constant voltage to the pump and let it run a little less noisy. It is not required but a good idea. If you are close to maxing out the 190 and the voltage drops you could get in a lean situation.

I had some problems with the Radio Shack™ 30A fuse holder during the rewire. Before I buttoned everything up, I tried starting - no go. Finally found that the fuse holder wasn't making sufficient contact with the fuse on one side. Smashing the holder with a pair of channel locks fixed it, but I was wondering if I was getting a fair amount of resistance at that junction. I know that they have much nicer fuse holders for car amps (I have a huge, gold-plated barrel fuse holder for my amps), but don't know if I should futz with it. Here's a picture of what I'm talking about (don't think I'd need one this beefy ):

You must be logged in to view this image or video.

I could also fork my FP supply from my 4ga amp power wire, but I don't know if I'd overload the fuse or introduce noise into my audio.

 

[JayRolla]

had some problems with the Radio Shack™ 30A fuse holder during the rewire. Before I buttoned everything up, I tried starting - no go. Finally found that the fuse holder wasn't making sufficient contact with the fuse on one side.

I had the same problem with my Amp wire kit on my old Dodge shadow 2.5 turbo(loved that car). I was 16 and stupid and put a spring inside it to make the fuse tighter. I thought I was so smart untill it started arching and I almost caught my car on fire. I welded the amp wire to the upper strut assembly. Just a stupid thing I did once thought you guys would see some humor in it.

 

[hottboost]

You dont want to spice off of your audio amp, as it could create noise resistance. But to anwser Mack's question I would use a heavy duty amp fuse holder. They are stronger. JaRolla I like that ! I found the link about the difference on the fuel pump here it is

http://www.roadraceengineering.com/fuelpumptechtip.htm

 

[JayRolla]

Log Log Log, Log Log Log

 

[kenamond]

Log Log Log, Log Log Log

Sorry. Haven't gotten around to it yet. Co-ed softball started, and my wife's been picking me up from the gym and driving us down to the games in our van. I'm always too wiped out afterward to motivate myself for a log. I just resumed weight lifting after a bout with tendonitis, and piling coed softball on top of that wipes this old man out. I play outfield betwee two women usually, and they don't run fast, so I cover 3/4 of the outfield, and it wipes me out .

I think about it every night, but for the past week, my aches, pains, and droopy eyelids win...or I've had too much beer at the ballfield .

I'm still a bit concerned about resistance at the crappy Radio Shack™ fuse holder for the FP wire. I went to Autozone and Radio Shack™ again to see about barrel fuse holders, but they didn't have anything very good, so I might buy a $7 gold-plated jobbie online to set my mind at ease.

Thanks for keeping interested! I really do appreciate it!

 

[hottboost]

Just let us know!

 

[kenamond]

Same old, same old.

3rd gear pull at 15psi boost. I include intake air temps below which are maybe a bit lower that any pull before by maybe 10*F (usually see 95*F intake temps). Leans out bigtime past 6k, and still see timing dips in the usual places.

I'm going to order a nice, gold-plated car audio barrel fuse holder to replace the crappy blade-style fuse holder. Recall that I had to smash the fuse holder with channel locks to even get the FP to kick on, so I think there's a fair amount of resistance on that new 10ga 12V line.

I'm no electrical guru, but can I test the FP voltage? I imagine that I can expose the relay, start the car, then measure the voltage on the 10ga pos. and ground wires at the FP with my multimeter. Also, where should I measure system voltage to make sure my alternator/regulator is generating sufficient voltage? I recall that the 1g loggers can log that, but I don't think it's available on a 2g.

Anyway, here's the log:

RPM Timing Air Temp O2v
2820.0 27.0 81.0 0.88
2852.0 27.0 81.0 0.88
2892.0 26.0 81.0 0.88
2948.0 23.0 81.0 0.88
3008.0 22.0 81.0 0.88
3076.0 21.0 81.0 0.90
3144.0 19.0 81.0 0.90
3200.0 16.0 81.0 0.90
3296.0 13.0 81.0 0.90
3368.0 11.0 81.0 0.90
3456.0 13.0 81.0 0.90
3552.0 11.0 81.0 0.90
3648.0 10.0 81.0 0.90
3768.0 10.0 82.0 0.90
3880.0 11.0 82.0 0.90
3968.0 11.0 82.0 0.90
4096.0 12.0 82.0 0.90
4204.0 12.0 82.0 0.90
4340.0 13.0 82.0 0.90
4464.0 13.0 82.0 0.90
4568.0 13.0 82.0 0.90
4680.0 13.0 82.0 0.90
4816.0 13.0 82.0 0.90
4916.0 14.0 82.0 0.90
5016.0 15.0 82.0 0.90
5120.0 15.0 82.0 0.88
5228.0 15.0 82.0 0.88
5340.0 16.0 82.0 0.88
5428.0 16.0 82.0 0.88
5532.0 17.0 82.0 0.88
5572.0 16.0 82.0 0.88
5712.0 17.0 82.0 0.86
5808.0 17.0 82.0 0.86
5888.0 18.0 82.0 0.84
5980.0 19.0 82.0 0.82
6124.0 20.0 82.0 0.78
6192.0 21.0 82.0 0.68
6264.0 21.0 82.0 0.62
6312.0 22.0 82.0 0.58
6400.0 22.0 82.0 0.54
6452.0 23.0 82.0 0.50
6516.0 22.0 82.0 0.48
6564.0 22.0 82.0 0.44
6620.0 23.0 82.0 0.42
6664.0 23.0 82.0 0.40
6712.0 23.0 82.0 0.38
6784.0 23.0 82.0 0.36
6820.0 23.0 82.0 0.36
6868.0 23.0 82.0 0.34
6904.0 23.0 84.0 0.34
6928.0 23.0 84.0 0.34
6980.0 23.0 84.0 0.32
7020.0 24.0 84.0 0.32
7044.0 24.0 84.0 0.32

 

[hottboost]

Man you have me stumped. I thought for sure that re-wire would help. Give me a while to put some thought into it.

 

[JayRolla]

Damn that sucks it didnt do much. Im having your same problem. Knock right at 6000-7000. Im going to buy some 650's and a SAFC for now to I can get rid of my knock in high rpms and im only at 12psi with a spike to about 14psi. I should beable to tune 15psi pretty good on just an SAFC and injectors right? All other fuel is stock.

 

[hottboost]

Damn that sucks it didnt do much. Im having your same problem. Knock right at 6000-7000. Im going to buy some 650's and a SAFC for now to I can get rid of my knock in high rpms and im only at 12psi with a spike to about 14psi. I should beable to tune 15psi pretty good on just an SAFC and injectors right? All other fuel is stock.

I would re wire the stock fuel pump. Then just go by your logs but if everything is right you should be fine. See I didnt re wire the fuel pump until I did the 190lph. I never went over 14psi with the stock fuel pump.

 

[toojung2die]

You and I have pretty similar setups, Mack. Same turbo, etc... I've been building up my mods with the goal to get 650cc injectors and DSMLink. Before this I've been logging with Pocketlogger so I would have a good idea of how my engine behaves with stock fuel management and 10-12psi. I didn't see evidence of pulled timing unless I ventured above 14-15psi. I never get timing advance as high as you but that's probably because I have higher ambient temps, engine temps and lower altitude.

As soon as I put in the 650's and DSMLink I was getting enormous knock readings on the DSMLink logs. I even saw serious pulled timing while just cruising with the intake in vacuum and no boost. I spent at least a week and $100 for a knock sensor trying to diagnose what I was sure had to be phantom knock because this engine never knocked before. When it came time to fill up the gas tank I filled it up with 100 octane. Within one minute of driving ALL the knock was GONE. Turns out the problem was a bad tank of gas. It wasn't phantom knock, it was real knock.

Can you buy some race gas to see if it makes a difference? Forget octane booster. Get some real octane in there for diagnostic purposes.

 

[kenamond]

You and I have pretty similar setups, Mack. Same turbo, etc... I've been building up my mods with the goal to get 650cc injectors and DSMLink. Before this I've been logging with Pocketlogger so I would have a good idea of how my engine behaves with stock fuel management and 10-12psi. I didn't see evidence of pulled timing unless I ventured above 14-15psi. I never get timing advance as high as you but that's probably because I have higher ambient temps, engine temps and lower altitude.

As soon as I put in the 650's and DSMLink I was getting enormous knock readings on the DSMLink logs. I even saw serious pulled timing while just cruising with the intake in vacuum and no boost. I spent at least a week and $100 for a knock sensor trying to diagnose what I was sure had to be phantom knock because this engine never knocked before. When it came time to fill up the gas tank I filled it up with 100 octane. Within one minute of driving ALL the knock was GONE. Turns out the problem was a bad tank of gas. It wasn't phantom knock, it was real knock.

Can you buy some race gas to see if it makes a difference? Forget octane booster. Get some real octane in there for diagnostic purposes.

But it makes absolutely no sense that I'd get consistent knock at 8-9psi boost. I've been putting like 1/4 tank every time I fill up (91 octane is the best you get up here) so that if I wanted to try the rest of my NOS octane booster I'd be able to have a higher concentration and up the octane more, but I'll try a different gas station next time. If it was a bad batch at that gas station, I doubt they'd have that over the past 2 months, right?

I have no idea where to get race gas around here. I've only ever seen it once back in like '97 in East St. Louis (almost filled up with the wrong stuff). I've read threads on making your own, but I don't know if I trust the recipe.

After my exhaust is done (3" DP-back), I'll be saving for an ECU and DSMLink. Then I'll save for fuel mods.

I already ordered a nice car audio barrel-style fuse holder to replace what's on there now, so we'll see if that makes a difference in my lean condition. I'd still like to know if there's a way to test my FP voltage. I saw an article on some other site where they gave some performance numbers for numerous pumps at a couple voltages, but I don't know what to do to see where I fall in their results.

Also, I've read on this forum that the stock FPR is pretty reliable, so I've not been questioning it, but could it be that it's fading, and my fuel pressure is low? If the FPR starts to go bad, do you get higher or lower FP? My guess is higher, but if it's lower, that could be contributing to the leaning-out. Or it could be the alternator; it's the original.

Thanks again guys!

 

[toojung2die]

Surprised you can't get race fuel anywhere. Around here it's not common but a few places carry it. Maybe having a race track in town helps.

Looking at your last log it's actually pretty good, timing-wise. What's shocking is your timing continues to increase even though your o2 voltage indicates you are dangerously lean. If you were running as lean as your o2 voltage shows you should have knock up the wazzoo and no where near the timing you get at redline. Stoich is .5 volts (14.7:1 a/f ratio) and that's where the narrow band stock o2 sensor is most accurate. You're reading less than .5 volts from 6400 rpm to 7000 rpm. Your engine should be toast if those readings are true. I'm thinking there's nothing wrong with your fuel delivery but something wrong with your o2 sensor. The stock fuel system delivers a rich 9.5:1 mixture at WOT. You haven't modded your engine enough to cause the fuel starvation at the modest boost levels your logs show. I know you can't rely on the stock narrow-bad o2 sensor to judge WOT fuel ratios but it can be used to indicate relative changes. Your o2 voltages start out on the lean side and then get impossibly lean. I wouldn't trust what you're seeing from your o2 sensor. How old is it?

 

[hottboost]

Surprised you can't get race fuel anywhere. Around here it's not common but a few places carry it. Maybe having a race track in town helps.

Looking at your last log it's actually pretty good, timing-wise. What's shocking is your timing continues to increase even though your o2 voltage indicates you are dangerously lean. If you were running as lean as your o2 voltage shows you should have knock up the wazzoo and no where near the timing you get at redline. Stoich is .5 volts (14.7:1 a/f ratio) and that's where the narrow band stock o2 sensor is most accurate. You're reading less than .5 volts from 6400 rpm to 7000 rpm. Your engine should be toast if those readings are true. I'm thinking there's nothing wrong with your fuel delivery but something wrong with your o2 sensor. The stock fuel system delivers a rich 9.5:1 mixture at WOT. You haven't modded your engine enough to cause the fuel starvation at the modest boost levels your logs show. I know you can't rely on the stock narrow-bad o2 sensor to judge WOT fuel ratios but it can be used to indicate relative changes. Your o2 voltages start out on the lean side and then get impossibly lean. I wouldn't trust what you're seeing from your o2 sensor. How old is it?

Going back over the log, there is only 1 dip at like 5500rpms. I agree that those o2 values look way out of wack. At wot mine only dips to like .95 and ranges from there to .97!

 

[JayRolla]

Yep I agree I would replace it. There is a couple places here in the springs with race gas. Call some shops im positive there is race fuel up in Denver.

 

[kenamond]

Yep I agree I would replace it. There is a couple places here in the springs with race gas. Call some shops im positive there is race fuel up in Denver.

As far as I know the O2 sensor is original. I'll replace it. I'll have to look around as to where to find a new sensor with the correct harness.

I'm not in Denver (6 hours away from me). There are some other small towns nearby, then Santa Fe, then Albuquerque. Santa Fe is 45 mins away, and Albuquerque is 1.5 hours away.

Thanks guys!

 

[kenamond]

I ordered a Denso front O2 sensor from oxygensensors.com for $54 shipped. When I did my turbo swap, I wasn't able to unplug it. Guess I get to figure that out now. It'll help seeing half of the plug on the new sensor so I'll know where to squeeze, which end to pull on, yadda yadda.

Got the new fuse holder, but now I gotta find some place that sells gigantic 30A barrel fuses. Doh!

 

[hottboost]

I ordered a Denso front O2 sensor from oxygensensors.com for $54 shipped. When I did my turbo swap, I wasn't able to unplug it. Guess I get to figure that out now. It'll help seeing half of the plug on the new sensor so I'll know where to squeeze, which end to pull on, yadda yadda.

Got the new fuse holder, but now I gotta find some place that sells gigantic 30A barrel fuses. Doh!

If I remember right the plug is bolted to the motor under the thermostat housing. There is a bolt that is tough to get to. If you unbolt it then you can get to the plug. Hope that helps

Carl

 

[JayRolla]

Thats a good price on the o2 sensor. I got my denso off ebay from ongreenperformance for $60. nice find