bontrager

I am thinking about adding a ported throttle body to my 2000 6 speed vert ( $100.00 additional for polishing; is that worh it)?

The car now has a cold air induction system, modified mass flow air sensor and smooth flow coupler, short tube headers, x pipe and cat back system.

Will I gain ANY low end torque.

Thank you

Bill Curlee

Well,,,,,, yes and no.. You will see a little HP (5-8 hp) gain and more importantly, some improved throttle response. Unfortunately, you will not have all the power that you have on the plate until you finish ALL your mods that you plan for now and get that thing tuned.

Each time you improve air flow into the engine, you disturb the factory tuning and the PCM has to adapt to correct for the change in air flow. Each time it corrects, the LTFTs get further and further in the PLUS ZONE. When that happens, your WOT AFR gets richer and richer. RICH AFRs mean less power than you would have if it were tuned properly and poorer fuel efficiency.

So,, thats the story in a BIG NUT SHELL!

What are your thoughts on getting your PCM tuned??

Bill

Bill Curlee

If the TB is properly ported,, being shiney will not really make that much difference. OH,, you eyes will see a difference.

I do all my own porting and have done it both ways.

Did this for a friend. Whe was getting his car tuned the next day and I had a few free hours:



LS2 TB for my 06 Coupe:



Ported LS2 vs LS1/6 TB



Heres a professionally done SHANER TB. VERY NICE JOB! Nice work on filling in the fresh air channel!!

bontrager

No problem in getting the PCM tuned. I had one done (not dynoed) after I added short tube headers. After the tune my gas mileage has been worse. A number of parameters were changed by the tuner via his laptop connected to something under my dash on the drivers side.

Thank you Bill

Bill Curlee

Unless the tuner takes the car on the road and fine tunes the VE table and gets the MAF table and LTFTs correct, you’re not going to change the fuel efficiency. Trust me on that one.

The tuner needs to spend some time in the passenger’s seat data logging while you’re driving and running thru different engine loads and RPMs and correcting those tables. Just dropping in a tune doesn’t address all that needs to be changed to make the engine run efficiency.

That’s why a good tune cost so much. It takes a skilled person, a lot of time and patience to get it right.

Bill

bontrager

Thank you Bill; can all of this be accomplised on a DYNO Tune machine that show different graphs on a computer monitor????

Tha tune would run me $400.00

Bill Curlee

The DYNO TUNE and the ROAD TUNE are TWO different animals. You can use the dyno to get peak HP and TQ info but when your DYNAMIC on the real road,, you will almost always have to retune a few tables i.e. MAF table, VE table PE Table and then Timing to eliminate KR (if any is observed) etc.......

If you don't accomplish this on the road fine tuning the above tables will be incorrect for actual driving conditions and,, your LTFT may not be correct and you will not see maximum power and engine efficiency.

With everything adjusted correctly for actual driving conditions your car will perform a LOT better. I gained power and an easy 3 MPG improvement in highway fuel mileage.


The tuner needs to use a WIDE BAND and tuning software and sit in the passengers seat while you drive. He will data log the PCM and adjust as necessary to correct the errors. I use EFI Live and the procedure is called AUTO VE Tuning. Once that is accomplished and you adjust the timing and WOT PE tables for correct AFR, they then adjust the MAF tables for correct LTFTs


Bill