LS-1 MAF translator vs ARC-2/ VPC

[Motohead1]

Originally posted by Ramchargers

WHO SAID BUG!? Ding, ding, you win. We discovered a software bug in the softeare that controls the operation of the LED sometimes. It in no way affects the operation of the unit just the light. We will offer a fix at no charge to anyone who wants it once we create one ( the easy fix is to just change the instructions )
Mike Licht

Cool beans. I like my special edition dimly lit model I have put 1500 miles on my car with the unit installed and its working great. Improved no-fuel cut track times comming soon.

 

[Pfunk47]

Just wrote Dave, will post reply when I get one...

 

[DCJ98GST]

I checked with Dejon this morning and he said they will be on the site in a couple of days. Forgot to ask wheather it is for the 1g's or 2g's or both.

 

[Tallen]

sounds great Mike, i'll take the fix. i am just happy i installed it right now. can we be reimbursed for emotional distress?

oh yea the bragging...
http://students.db.erau.edu/~szabafab/talon/Picture001.jpg
http://students.db.erau.edu/~szabafab/talon/Picture002.jpg
http://students.db.erau.edu/~szabafab/talon/Picture003.jpg
http://students.db.erau.edu/~szabafab/talon/Picture004.jpg

 

[Ramchargers]

We will be shipping 1G units today, lots
Mike

 

[DrZiplok]

Firstly, I pulled the honeycomb from the GM MAF last night, and had to *drastically* lean out my AFC idle setting. My '90 ECU will only trim down to 80%, and I was sitting at .90 O2 volts at idle. It's now more in line with the rest of my settings in the 5-20% lean range, down from 5% rich.

Secondly, I'm getting *terrible* trailing-throttle surge; backing off the throttle when coming into a corner almost guarantees a violent surge, much worse at higher rpms. Oddly, dropping more throttle often results in less surge; it's when you just feather it a bit that it surges the worst.

I have bad tip-in knock, so I'm not running a lot of boost (~15psi); I'm not sure if that might have anything to do with the problem.

 

[Motohead1]

Originally posted by DrZiplok
Firstly, I pulled the honeycomb from the GM MAF last night, and had to *drastically* lean out my AFC idle setting. My '90 ECU will only trim down to 80%, and I was sitting at .90 O2 volts at idle. It's now more in line with the rest of my settings in the 5-20% lean range, down from 5% rich.

Secondly, I'm getting *terrible* trailing-throttle surge; backing off the throttle when coming into a corner almost guarantees a violent surge, much worse at higher rpms. Oddly, dropping more throttle often results in less surge; it's when you just feather it a bit that it surges the worst.

I have bad tip-in knock, so I'm not running a lot of boost (~15psi); I'm not sure if that might have anything to do with the problem.

So your using a AFC along with the translator?

 

[Tallen]

i have noticed my bucking when letting off the throttle disappear. start from scratch again and see of you can come to diff settings.

 

[DSMraver]

Originally posted by DrZiplok
Firstly, I pulled the honeycomb from the GM MAF last night, and had to *drastically* lean out my AFC idle setting. My '90 ECU will only trim down to 80%, and I was sitting at .90 O2 volts at idle. It's now more in line with the rest of my settings in the 5-20% lean range, down from 5% rich.

Secondly, I'm getting *terrible* trailing-throttle surge; backing off the throttle when coming into a corner almost guarantees a violent surge, much worse at higher rpms. Oddly, dropping more throttle often results in less surge; it's when you just feather it a bit that it surges the worst.

Zero your AFC, and use the translator settings to get *close* then only use the AFC to fine-tune.

I'd be willing to bet your lo-hi changeover points are different now with the translator installed which will make a difference, and you should baseline the settings with the translator, it's easier that way.

 

[Ramchargers]

Those are NOT typical of descreen results, I think John hit it right, Just use the AFC to fine tune, or not at all
Mike

 

[DrZiplok]

This is an old-school S-AFC, it doesn't have high/low changeover points (you can tell that from looking at my profile).

I have been meaning to switch to using the translator for tuning, but since I had the car pretty well dialled in with the AFC, I left the translator at 1:1 while I was moving.

I was seeing the surge before de-screening as well; it's just worse now. I'll post again once I've pulled the AFC out of the loop and have things sorted with the translator.

 

[DSMraver]

Not to mention that the BOV is *awfully close* to the MAS. I don't think that's a good idea having the MAS setup being that close to the BOV.

 

[Tallen]

Originally posted by DSMraver
Not to mention that the BOV is *awfully close* to the MAS. I don't think that's a good idea having the MAS setup being that close to the BOV.

i assumed it would be b/c this way the backflow of air from the throttle body being closed would be less, thus less backed up ir would be hitting the MAF. isnt that the purpose of the BOV afterall?

 

[DSMraver]

Air is elastic. Normally a closely attached BOV would be good for the reasons you mention, but in the blow-thru application I think I'd want it mounted a bit further away, like near the start of the UIC pipe.

Or, it could be something completely different, and we're both wrong.

 

[Tallen]

were both prolly wrong...i bet it needs to be in the middle of the pipe

 

[Pfunk47]

Tallen, I talked to you yesterday on AIM, How much, if any, has your gas mileage improved (you said you were rich before) and would you mind writing up a small before and after comparison and review for everyone.

Thanks

 

[Tallen]

goin to the beach right now, but i am seeing about a 7-10 mpg improvement. i had an aftermarket fuel pump, no regulator, and was jsut running rich.
i told the car i had smaller injectors than the 450's to adjust for the higher fuel pressure...so basically i am back tot he stock fuel setup till i get my B&M reg and do the mod to it that allows me to lower pressure.


adjusting WOT was easy cause i had the a/f meter. mid..i jsut set btwn idle and WOT. and idle i jsut played by ear.

 

[ttawd3s]

You do know that the B&M FPR can ONLY raise fuel presure and NOT LOWER it, right ?

That's not a fact from me, but that's what I've read MANY times. If it could lower presure I'd take the one off my civic and put it on my stealth R/T ( basiclly the same ).

Anyway, you may wanna research the B&M before you buy/install it, if I'm wrong just smack me a few times, but just trying to give you a "heads up".

 

[DSMraver]

Tallen: that explains it. I got off-throttle bucking with a hacked mas when I had a supra pump, 660's, AFC, and no FPR.

The extra fuel (due to overun) and the non-linear fuel pressure will cause this. I'd be willing to bet that with an adjustable FPR, and linear fuel pressure, that your bucking problem will disappear.

 

[ttawd3s]

a "non-B&M" type AFPR (still using the factory FPR ) should solve the problem, but I'm just saying I don't think the B&M will.

If you want rail mount... http://www.chargedair.com

But he kinda takes a while to ship it..

 

[DSMraver]

The problem with B&M *type* FPR's that utilize the stock FPR is that the stock return orifice in the FPR is too small to bypass enough fuel the way it's designed.

The spoolinup regulator will fix this, and yes I know there's a ghetto-style mod for those B&M's, but when it comes to fuel, I'd spend the extra dough to be safe.

 

[Tallen]

Originally posted by Tallen
so basically i am back tot he stock fuel setup till i get my B&M reg and do the mod to it that allows me to lower pressure.

you guys missed that....well cept DSM Raver

i may get a spoolinup...how much? chargerair is 150 plus gauge.

 

[DrZiplok]

Just to pull this back onto topic...

I decided that sleep was less important than my car, so I switched over to tuning with the MAFT rather than the S-AFC (still in circuit, but all-zeroes right now).

On my setup (see profile) with the MAF screen removed I have base set for 550s and idle at 3. This seems to be giving low fuel trim around 95-100%, so I may go back to 2.

The mid and wot trims are still at zero, and EGTs/O2s are well within the sane range. I'm still pulling 20+ knock counts on sudden throttle transitions though.

On the brighter side, however, the off-throttle surge is gone, so I have to conclude that this was an artifact of the S-AFC's rpm-based rather than airflow/rpm-based mapping as used by the MAFT.

 

[peregrine]

i know this may sound like a stupid question ziplok but are you using premium fuel?

 

[peregrine]

sorry resubscribing. i accidentally purged my subscribed threads.