Translator & Direct Scan question

[turbogto]

Wondering if I am the only one having this problem:

When looking at my O2 readings in DirectScan I always get a large jump in the O2s right as I floor the car. It stays up in the 860-880 range for 2-3 secs then slowly comes down like a ski slope until I am flatlining around 740 from 75-110mph with EGTs around 1650-1700.

The boost comes in slow for a TE44, and the power is less than I would expect from these components and boost level. I'm beginning to suspect it may be this big rich condition I'm seeing early in the run.

The car has always done this, even before the Alky when it had 40 lb injectors. I have tried switching to another known good stock MAF and it still does it.

Been working with Eric at TurboTweak(when it comes to chips, the man is THE MAN). He has made a lot of headway with the tuneup in general and the car runs the best it ever has. He has succeeded in moving the point when it goes rich from before I can get my foot to the floor, to about 2 secs into the run, but then it does it, though not as bad.

I have noticed looking at other people's Direct Scan runs, that the cars with Translators don't seem to do this, or don't do it as bad. I've seen a few go straight to 780 and just stay there for the entire run. Is this my imagination or does the translator & LT1/LS1 MAF really make a difference? If so does it matter which you use: Translator/Translator Plus, LS1/LT1 MAF??

Since my stock MAF is fine, and Eric says he has a few more tweaks to try, I don't want to spend the cash if I don't have to, but I'm just curious if anyone else has run into this.

Thanks

Pete

 

[Sleeper]

With your combo, you should not have a problem spooling the 44, so I suspect something is amiss mechanically. Have you done the usual checks for vacuum and exhaust leaks?
Are you running a good AC Delco O2 sensor?
Is you cam sensor setup correctly?

What are your idle blm's and cell 15 blm's ?

What are your translator settings?

Paul

 

[BEATAV8]

A major factor contributing to the high O2 numbers at the start of the run is that the O2 sensor is not very hot. When the sensor is cool, it reports higher numbers. (this is normal... per the textbook)

Also, commanding a leaner "low gear fuel" A/F ratio can reduce the low gear O2 numbers. The extender chip does this. Perhaps the files you have been looking at are from cars running this type of feature?

I second the note about a good AC Delco sensor. I have tried others (NAPA Echlin, Standard, Bosch) and none work as well as the stock AC Delco.

Where are you from in Chi Town?

 

[turbogto]

Thanks for the replies.

I do have a recently replaced(2-3,000mile) AC Delco O2 sensor in it.

I went on a major vacuum leak hunt a few months ago including plugging up the intercooler and pressurizing it to check for leaks.

I tried the old GM Top Engine Cleaner in the PCV hose to check for exhaust leaks and did not see any smoke in the engine compartment and I cannot hear any leaks. I am considering removing the driver side header just to look at it, but I am afraid I may cause a leak where there isn't one now.

My BLM 0 is around 134, BLM 15 is 124, tho the Turbotweak chip locks it at 130 at WOT.

Don't have a translator. Trying to decide if there's any advantage in going to one.

I do still have the stock convertor as I want to try and retain use of 1st gear on the street.

I am regretting going with the Precision Front Mount Intercooler now as it has greatly raised my coolant temps and now that I'm running alcohol, charge cooling is the least of my worries. I moved the IAT sensor to the plenum doghouse for a while and according to DS, I have been seeing temps in the 78-88* range for the air going into the intake manifold which I'm afraid may be too cool to keep the alky atomized.

I don't know what you mean about the translator commanding less fuel in the lower gears. Is it in the chip, is it a knob you turn??? I guess I don't really understand the capabilities of the translator. Maybe you could point me to a good primer on that.

I'd also like to see a few normal DS runs with a translator if anyone would like to send me some. I'd be happy to send some of mine along if you like.

MJRWOOD, I am in Evanston. I have been up your way a few times to the Cyrstal Lake Cruise Nights and have a few friends in that area.

Thanks for the help

Pete

 

[BEATAV8]

Hello again Pete
The low gear / high gear fuel commands come from the chip, not the translator box.
The extender chip I have commands an air fuel ratio of 12.6:1 in low gear. When the trans switch for 3rd gear comes on, the A/F ratio command drops to 12.1:1. On a side note, 2 degrees of timing are also pulled out at the same time.

It can only get away with this because the translator is present, reporting MAF numbers that are useable. Regular chips cannot do this very well because the pegged MAF has no valuable data to provide.

This site is probably the best place to get info on the translator / extender. turbomike.com also has some info.

 

[turbogto]

Thanks MJRWOOD.

Do you use Direct Scan?

Does Direct Scan still work with the Extender chip??

Eric has really done a super job tuning my car, so I'm reluctant to start all over. This O2 surge in the early part of the run is the only sticking point and he tells me he has another chip in the works to address it, so I'll see what he comes up with.

What would happen if I just went to the translator and kept my existing chip. Any benefit???

Pete

 

[BEATAV8]

Yup I use direct scan. I will try to send you some files tomorrow. DS works fine with the extender chip, but you have to make note of the T+ timing adjustments because they will not show up in DS files. DS will only show what is programmed into the chip, and the translator timing adjustments are not there. The translator + intercepts the timing signal and makes adjustments, then sends it on to the ignition module.

In my opinion, the translator is not much of a performance benefit unless the extender is used with it. The trans plus is useful with a standard chip, but mostly because the spark timing can be adjusted at the twist of a knob.

 

[turbogto]

Cool. I'll send you one of mine.

 

[2QUIK6]

Hey Pete, have you resolved this problem?
I have the same problem, but it was there with the original good AC Delco MAF and its still there with my Trans+ w/LS1 MAF, without extender chip.

 

[turbogto]

2Quik6,

Send me a Direct Scan file if you have one and I can tell you a lot more. TurboDave or MJRWOOD may want to chime in as they have been helping me also.

From what you have said, it sounds like the Extender chip may be a good investment as I have been told that you can program it to lean out the injectors a little in 1st & 2nd gear which may help your problem.

I'm trying to decide if I should go this route myself as my stock MAF is fine and Eric at Turbotweak has tuned my car up the best it's ever been, so I'm reluctant to lay out the cash if it makes no difference.

Turbo spool is a big issue with me as I still have the stock convertor because I like to use 1st gear on the street(with Nittos, of course).

I suspect the high O2's and subsequent ski slope I see early in the run are hurting my spool up, but I haven't looked at enough DS files to be sure.

I would really like to see some 0-100+mph Direct Scan files from a 11-12 sec car running 50lbers with the translator/extender that is able to launch without lifting and has a nice flat O2 curve.

Most of the DS files I have looked at are from cars with big convertors that have to be pedalled off the line and I suspect that has an influence on the O2 curve.

Let me know what you find out

Pete

 

[2QUIK6]

Pete, I just sent you the DS file from a pass last weekend. I have 40# inj and a 2600 stall convertor and run low to mid 12's consistantly with the setup in my sig.

 

[turbogto]

Man, I thought my runs were confusing to look at. I can't make heads or tails out of that one.

Got a 0-100mph laying around anywhere?

I sent you one of mine

Thanks

Pete

 

[2QUIK6]

Originally posted by turbogto
Man, I thought my runs were confusing to look at. I can't make heads or tails out of that one.

Got a 0-100mph laying around anywhere?

I meant to tell you the burn out and staging were part of the scan, the pass is at the end of the file. Easier to spot if viewed in "Scope" mode and look at the speed graph. Sorry about that.

 

[turbogto]

OK, got it and emailed you.

 

[Expendable]

Ah, so THIS is where you hang out, eh, Pete?

It's your pal from Sears...

 

[turbogto]

Yeah, it's me.

Still trying to figure out what my Direct Scan O2 readings should look like and whether a newer style MAF or Translator chip will help.

Too cold to test so I hang here and try to get smarter...it's a long road.