Dangers of Running Rich - 6G Celicas Forums

Dangers of Running Rich, 3sgte owners

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Sep 30, 2004 - 12:25 PM

jgreening

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QUOTE

How do you figure 180whp at 12psi? The JDM 3s's with JDM ecus are rated a 225hp at 8psi so your close to 190-195 at the wheels right there. With 12psi your kicking almost 210 at the wheels, I would think.

221 stock. 10-20% loss through the drive train is 177-199. Maximum stock boost is 10-11 psi. I am not raising it from that. I said 10psi, not 12psi (although I do have an aftermarket intercooler....).

Bottom line, I am not going to play with fire any more. The pump has been ordered.

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QUOTE(lagos @ Jul 10, 2006 - 1:55 PM) [snapback]454118[/snapback]

i know your trying to do the right thing for your motor, but this is one of those times where you should just trust the guys who have had their swaps for a while and have done a ton of research into this.

Sep 30, 2004 - 12:54 PM
Supersprynt View Member Profile Enthusiast Joined Feb 10, '03 From Connecticut Currently Offline Reputation: 11 (100%)	I've never heard 221 stock, only 225. Now, 10%-20% is HUGE difference, and secondly 20% is way high for FWD and RWD cars. I think Eclipse GSXs get 25% loss and they're AWD. I think that FWD in general avg 12% drivetrain loss and RWD about 14%. That said we'll use the avg of ur numbers for argument sake. 221 x 15% = 188whp. This is why I was asking where you got your figures because you said at 10psi ur expecting 180 at the wheels, when it should be roughly 188 at 8psi. From what I've heard its about 7hp per pound of pressure you turn the boost up. Lets say 5, just to prevent overestimation. 231 x 15% = 196whp. Just to see the figures on 12%: 221 x 12% = 194whp. 231 x 12% = 203whp. 256 @15psi x 12% = 225whp. But bottom line is not good using the stock 5sfe pump. This post has been edited by Supersprynt: Sep 30, 2004 - 1:09 PM -------------------- My Flickr My eBay _Perpetual Aperture_

Sep 30, 2004 - 5:56 PM

Doge

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QUOTE (thedevilmaycrie @ Sep 30, 2004 - 8:06 AM)

QUOTE (Doge @ Sep 29, 2004 - 6:07 PM)

QUOTE (jgreening @ Sep 29, 2004 - 9:12 AM)

Lagos, I am still running the 5sfe pump. Jayson claims it will be fine up to 18 p.s.i. Even with the 5s pump, the mixture is way rich. Anyway, the pump only supplies what is demanded from the ECU so, in general, the pump shouldn't act to cause rich conditions even if it is way overkill.

Also, there is a very interesting thread over on mr2oc.com that suggests you should never upgrade to a supra pump unless you upgrade the fuel rail. It was started by Wolfkatz (sp?) and has a lot of testing to back up his claims - although I must admit, I couldn't follow much of the fluids engineering hyper talk. Also, its quite possible that the conclusions only refer to conditions above the horsepower levels we find ourselves at - so far.

Running the N/A pump is dangerous. You're seriously just playing with fire... our pumps can pump enough fuel for the 3s.. but its RIGHT on the line. Any more power and its going to cause alot of problems. And if your pump is however many years old... its going to decrease in efficiency. I wouldn't risk it JGreening, you should get a pump asap. Here's the proof. Read the whole thing... you'll be glad you did!

N/A Fuel Pump BAD!
Turbo Fuel Pump GOOD!

The walbro fuel pump is $80 and is a piece of cake to install.. its just worth it knowing your engine will get all the fuel it needs.

And that test about the fuel pump that you talked about on mr2oc... that was a test on 550 injectors on the stock fuel rail. Having a upgraded fuel pump will do no harm to our engines... we are pretty much putting in a fuel pump that is pretty close to the alltrac ones that the engine was meant to run with.

also on the fuel pump resistor... all it does is, at idle it kicks downt the amps that is allowed to the pump... making it work less (basically turning it down) at anything above idle it kicks it back up to full power. Fuel pumps are either on full blast or off... there is no in between, unless you have a resistor... which isnt necessary

doge is right i fried my #4 piston from that.... luckly the cylider just ended up needing a little bit of honing i learned my lesson and you dont wanna use a walbo without the use of a high power regulator..... i say use the mr2 stock fuel pump but thats just my opinion from trail and error

you had the stock n/a pump when you fried your piston, devil?

Sep 30, 2004 - 6:26 PM

Coomer

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QUOTE (Supersprynt @ Sep 30, 2004 - 10:54 AM)

I've never heard 221 stock, only 225.

The JDM ST185 3S-GTE is rated at 225 PS, which is approximately 221.9 horsepower.

Anyway, good discussion...I'm learning a lot.

--------------------

New Toyota project coming soon...

Oct 4, 2004 - 4:42 PM
Supersprynt View Member Profile Enthusiast Joined Feb 10, '03 From Connecticut Currently Offline Reputation: 11 (100%)	http://www.mr2oc.com/showthread.php?s=&threadid=55214 Walbro a NO NO! After reading through this <very long> article(s) I dont kno if im putting in this walbro because it seems to mess around with the fuel rail and cause pressure drop. This can lead to running rich in some cylinders, destroying them. N/A pump results: http://www.mr2oc.com/showthread.php?s=&thr...hlight=pump+dog This post has been edited by Supersprynt: Oct 4, 2004 - 5:27 PM -------------------- My Flickr My eBay _Perpetual Aperture_

Oct 4, 2004 - 7:21 PM
lagos View Member Profile Enthusiast Joined Aug 31, '02 From Philadelphia, PA Currently Offline Reputation: 8 (100%)	so.... if fuel pressure is controled by the injectors and the ecu, why do people get FPRs and we dont. -------------------- 15PSI - 30MPG - Megasquirt Tuned

Oct 4, 2004 - 11:18 PM
Supersprynt View Member Profile Enthusiast Joined Feb 10, '03 From Connecticut Currently Offline Reputation: 11 (100%)	we do have FPRs, stock FPRs. -------------------- My Flickr My eBay _Perpetual Aperture_

Oct 5, 2004 - 1:47 PM

jgreening

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QUOTE

After reading through this <very long> article(s) I dont kno if im putting in this walbro because it seems to mess around with the fuel rail and cause pressure drop. This can lead to running rich in some cylinders, destroying them.

The way I interpret that thread on mr2oc.com is that the fuel pressure drop across the rail is bad for tuning. If you were to try to tune for a 11.5/1 afr, the afr is an average figure for all 4 cylinders. The fuel pressure drop across the rail means that some of the cylindars are more rich and some are more lean.

The good news is that our engines run exceedingly rich. So, while I probably wouldn't do aggressive (or really any) tuning prior to a rail upgrade, I do not think merely adding the Supra TT pump and retaining the stock 440's is going to cause the problems set forth in that thread.

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QUOTE(lagos @ Jul 10, 2006 - 1:55 PM) [snapback]454118[/snapback]

i know your trying to do the right thing for your motor, but this is one of those times where you should just trust the guys who have had their swaps for a while and have done a ton of research into this.

Oct 10, 2004 - 12:30 AM

YellowTwo

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QUOTE (97sccelica @ Sep 29, 2004 - 10:17 AM)

but other than that, dont worry about it, unless its so rich that it bogs nearly to the point where the engine stalls

What's the danger in having it so rich that the engine stalls? My car (91 MR2t) has been doing this, but it only stalls sometimes. Usually the RPMs will just jump up and down for a few seconds, then even out at the normal idle state. However, on rare occasions it will stall.

I think I'm beginning to figure out the problems my car has been having. It has 550cc injectors with a Supra fuel pump, but NOT an upgraded fuel rail. I've heard the upgraded fuel rail is vital after upgrading the fuel pump and injectors. I'm trying to find out if this is the missing piece to the problem.

The S-AFC supposedly (i.e. according to the seller) was tuned correctly when I bought the car. But on that setting, the car would not go past 4k RPMs (but idles fine). Then when I set it to the other data file (i.e. the default setting) it ran fine, except for the low/jumping idle. What I'm thinking is: a) The S-AFC is tuned for the 550cc injectors, but having the stock fuel rail is causing it to not go above 4k RPMs, or b) The S-AFC is not tuned correctly.

Any ideas?

Oct 10, 2004 - 3:30 AM
Doge View Member Profile Enthusiast Joined Dec 2, '02 From Portland, Oregon Currently Offline Reputation: 0 (0%)	Yeah you have to know what you're doing to get those piggyback systems to run correctly. I suggest either get a fuel rail, learn how to tune it yourself, take it to a tuner, or go back to the factory injectors and pump with the rail you have.

Oct 10, 2004 - 4:15 PM

YellowTwo

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QUOTE (Doge @ Oct 10, 2004 - 1:30 AM)

Yeah you have to know what you're doing to get those piggyback systems to run correctly. I suggest either get a fuel rail, learn how to tune it yourself, take it to a tuner, or go back to the factory injectors and pump with the rail you have.

The problem is the previous owner didn't give me the stock fuel injectors and pump, or I would totally go back to those because there's no reason for my car to have those uprgades. So, I've already ordered the Wolfkatz fuel rail, and hopefully that will help. After I install the fuel rail, I'll try the original S-AFC setting that was supposedly tuned correctly and see if that works. If not, I'll just have to get it re-tuned.

Oct 15, 2004 - 3:17 PM

jgreening

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I just thought I would share this answer to my original question about whether it is dangerous to run rich:

QUOTE

Overly rich is arguably safer than overly lean, but both are dangerous and undesirable. Running a super rich air fuel ratio is not healthy and will harm your motor. It is also an indication that your tuner does not know what he/she is doing with boost and/or timing. Healthy combustion requires the right ratio of air to fuel being ignited at the right time for optimum burn. You may not realize this, but fuel is an anti-detonant. If you see a very rich mixture (fuel dumping) it is the hallmark of a tuner trying to cope with inappropriate timing and or boost mapping. Don’t think rich is dangerous? Too rich and carbon will begin to build up in the cylinder head causing pre-ignition, sparkplugs will begin fouling and misfiring, your catalytic converter will clog up, and the long term health of your engine will be compromised. Matter of fact, if you go too rich, you can cause fuel preignition, which goes hand in hand with detonation, which triggers the knock sensor, which the ECU sees, and then the ECU retards the timing, and the EGTs go up. And so begins the vicious cycle to medium and long term engine damage. It won't be the sudden and catastrophic failure one might see with a sudden lean condition, but will do great harm in the long run.

This is from tuner Ricky B on mr2oc.com, operator of MR Controls and author of the 3sgte Power Primer. Good source.

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QUOTE(lagos @ Jul 10, 2006 - 1:55 PM) [snapback]454118[/snapback]

i know your trying to do the right thing for your motor, but this is one of those times where you should just trust the guys who have had their swaps for a while and have done a ton of research into this.

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