'97 Riviera 3800 Turbo Tuning request

[Helodown66]

I recently purchased a '97 Riviera with the 3.8L with supercharger. This is a great little car, but needs some tuning help, as it is only getting 20MPG at the most. I have replaced spark plugs & wires and cleaned throttle body.

I am looking for someone who knows their way around the 3800 and the HP tuning program. i.e. I down load the present tune & tables and e-mail for evaluation and changes. I am guessing vehicle is under tuned. I am willing to pay for this help. I know just enough to know not to fool with all the different tables.

Thank you,


Helodown66 in Big Sky

 

[krom]

Riviera Performance

 

[kshef]

no sense in paying for anything...post your .hpt file...more than happy to help

 

[Helodown66]

Thank you!!!

I greatly appreciate your input.

I will download file and post it, hopefully today.
Very busy with helping my wife, who just came
home with a new hip joint.

 

[Helodown66]

Thank you, I was not aware of that site. Looks great.

 

[murphinator]

I recently purchased a '97 Riviera with the 3.8L with supercharger. This is a great little car, but needs some tuning help, as it is only getting 20MPG at the most. I have replaced spark plugs & wires and cleaned throttle body.

I am looking for someone who knows their way around the 3800 and the HP tuning program. i.e. I down load the present tune & tables and e-mail for evaluation and changes. I am guessing vehicle is under tuned. I am willing to pay for this help. I know just enough to know not to fool with all the different tables.

Thank you,


Helodown66 in Big Sky

so plugs & wires are done - good start , how about fuel filter , air filter , clean maf sensor ( with crc aerosol maf sensor cleaner) and tire pressures ?

the 20 mpg's what type of driving ? if city and lots of stop and go you probably wont gain a lot , if thats highway you should be able to gain approx. 10 mpg between the mechanical items like the ones I listed and anything else that may be lacking maint. wise

definately post your tune , like K Shef I have hpt and would be glad to take a peek for you.

My dialy driver regal gs spent 3 years commuting between Maine & Mass 6 days a week with 90% of the commute on rt 95 between 70-75 mph , by using the timing histograms for data and adjusting the high octane timing table using that data I was able to get 31-32 mpg average by maximizing my timing in the cells I spent the most time in on my commute , those cells now see 48-50* of timing

 

[Helodown66]

Thank you for your response. Fuel filter - new, air filter - new, tires 36 lbs. Have not cleaned MAF.
Driving mostly on highway 60 to 70 MPH, not heavy on the gas.

Will post tune ASAP.

Thanks again for the input. I figured someone would know what to do.

 

[murphinator]

you do know that motor is premium fuel only right ? should have a label in the gas door.

if you or the previous owner ran regular in it a lot it could have reverted to the low octane timing table which would numb the car timing wise quite a bit.

you may want to disconnect the battery for half an hour to erase history

bad pre-cat 02 sensor can tank mileage also- sounds like you have most of your bases covered otherwise

 

[Helodown66]

'97 Riviera 3800 Tuning request

Yes - using prem.

Do not know history of vehicle.

Have not disconnected battery.

Please find hpt file for my Riv.

Vehicle has 101,000 miles.

I have changed all fluids.
New Belts
New struts
New Thermostat
plugs, Wires, air filter and fuel filter.

Now I am unable to upload the HPT file computer says "Invalid Format"

What am I doing wrong? I copied & named file to desktop, but will not upload.

I guess if you are willing send me your e-mail and I will send it that way.

My cell is 406 885-3281

Hans Helm

Thank you.

 

[Helodown66]

'97 riviera 3800

Ok I can not send a "HPT" file, but perhaps I can send individual tables.

Let me know if this works. Also what other tables you may want to look at.

Thank you.

Hans

 

[kshef]

on a stock car there isnt much to do with the tune

you can play with the timing and change the transmission shift points, time and line pressure

 

[murphinator]

on a stock car there isnt much to do with the tune

you can play with the timing and change the transmission shift points, time and line pressure

agreed.

the stock tune should be good for 25-28mpg I feel on your car at 65-70 ish mph with everything in good state of tune/mechanicals.

beyond the timing adjustments kshef mentioned the only way to get more mileage by tuning would be to run lean cruise which U.S. tunes dont have as an option - the australians are able to run 15-15.5 afr but here in the u.s. you cant because it causes nox emmisions to go up . if you do try to lean it out your fuel trims will just correct back to 14.7 based on 02 readings (this is my understanding - I havent messed with it personally)

possibly you could defeat that by running open loop full time or by using tiny tuner to access your entire tune where as hpt only accesses portions of it but from your first post this is probably deeper than you want to get involved.

If you were to add some breathing mods you can get better mileage, I recall a moderator on the regal forum 3 or 4 years ago that had a riv was getting low 30's mpg with headers, rockers, intake , tuning . Car also ran 13.7 ish....

kshef may remember him , I believe he got involved with a riv forum as an owner or something , his sig had a pic with his valve cover off revealing red high ratio rockers - the useless stuff the mind retains :biggrin:

 

[Helodown66]

I am willing to do what is necessary to get the job done. Please understand my knowledge level is limited, but I do have the HP tuner program. I did do a diag on the vehicle and no codes were shown i.e. no bad sensors. I just barely understand the difference between open and closed loop.

Were you able to open the individual tables I posted? Apparently I can not upload or post the hpt.txt.

Please advise

 

[murphinator]

the attached files are not in any format - just numbers , without the axis of the tables in place hard to see much without spending some time figuring out whats where.

but the e mail you sent me of your tune is fine and I opened it along with my wifes 98 regals stock file using the compare feature to check the timing differences. under .36 cyl airmass which is where you should be all thetime at cruise both high and low octane tables are identical - up top your timing is pretty numb compared to the regal tune down a couple or 3* most places and especially bad in the low octane table in the mid throttle range.

whats odd is that the w body's are more prone to knock because of the u bend in the downpipe at the rear 02 sensor which the full size cars dont have ?

how about a scan log to my e mail to look at ??

open loop vs. closed loop is simple

open loop you run off hard coded table values for fueling , closed loop is when you are warmed up and the 02 sensors influence your tune based on rich or lean readings so the vehicle can correct for sensed oxygen content remaining in exhaust to keep as close to stoich as possible