Hello all;
New here and to Corvettes and I'm looking for some advice on upgrading the engine a little. I have a 2004 coupe that appears stock but the mufflers have been changed to another brand.
Looking thru catalogs I see a number of intake system kits (Vara-ram, K&N, etc) and looking for general comments about their effectiveness, ease of installation, etc. And if I install a new intake system, does the throttle body need to change?
Change the Mass Air Flow meter?
Do the injectors need to be changed to meet the increased airflow?

Finally, what are thoughts on using things like the Hypertech or Predator reprogrammer? Are they worth the money to use with the above intake changes?

My apologies for all the questions, I want to make the upgrades as smoothly as possible and only do it once. Not looking to make this a supercar, just improve performance a bit more. Thank you,
New Guy

 

i'm new, and i've had my 03 coupe a4 for about a month now. where i have started was doing the zip tie mod and made a trade deal for a diablo tuner. my plans down the road will include headers, gear swap, possibly vara ram intake stall and cam. probably in that order too.
after having the diablo tuner, what i've noticed is its nice with the auto car. motor performance wise i'm not feeling alot of change in power with the tunes and i've been adjusting my fuel trims lately looking for more.
i personally would not do the hand held if you have plans of changing more than a very few bolt ons, especially if you have a manual. right now my opinion of the hand held tuner is its nice to adjust the trans, not much out of the motor. i'm still learning it though.

if you plan on alot of upgrades, get a tune by someone who already knows these cars. my opinion.

 

If you start with a (Vara-ram, K&N, etc) change you will not need to change the MAF or injectors.
the hand held tuners can help by enhancing these mods ex. fan temp adjustments, timing and maybe trans shift point. maybe a forum member lives close and will help out with this.

If you go beyond these simple mods get an experienced shop to retune your car

 

Wellllllll,,,,,,,,,,,,,,,,,,,,,,,,,,,, I had C5 Vettes of one year or another since early 98 and done a LOT of stuff to them that,,, Now that I looked back on and said "Man,, that was DUMB" or "WOW,, that was a WASTE OF MONEY"

So,, heres my take ,,, and your going to get 20-30 other points of view with some what different recommendations.

COLD AIR INTAKE SYSTEM. IMHO,, VARARAM or some other true FRONT OF THE CAR system like vararam. It flat works and makes a difference!

PROGRAMMERS. Nothing beats a TRUE in the shop tuning session! PERIOD!

HAND HELD TUNER= If you have a MANUAL Trans, the hand held tuners are not all that useful... If you have a A4,, they can maks a big difference in how your tranny performs.

So,, when do you need a tune?? Only when you make enough performance changes to screw with engine efficiency and Volumetric Efficiency tables. I would say the addition of headers and vararam would fit that bill.

Any performance mod that makes a useful and seat felt increase in performance normaly needs a tune to get all the power and efficiency on the table.


INJECTORS = NO!!! You DO NOT need bigger injectors! Your are good for a LOT MORE HP!

MAF = NO,, The MAF that you have is good up to 450-500 HP range. Other things will restrict power WAY before your MAF becomes an issue!!

Bill

 

Congrats on the new car !!
Yes-- a CAI is a great 1st mod--Make sure if you live in a state that requires to have the intake CARB certified you get one that is--they are more pricey--If not required any CAI in fine -Regardless of what people say most only make apprx 8-12 RWHP
Your car already has a LS6 intake manifold so that is good
NO on the larger T-body or larger injectors--Not needed and can create driveability issues
ABSOLUTELY NO on changing the MAF---do a search on the forum to read all the horror stories
And finally as far as any handheld tuner--These cars are very well tuned bone stock-So don't expect much maybe 8-10 RWHP---
A mail-order tune would be far superior--Especially if your car is an A4--You can make any C5 3-5 tenths quicker in the 1/4 mi simply with tranny tuning alone and not even touching the eng. !!!
If you are planning any future more serious mods ( hds/cam/LT hdrs) you may look into getting your own tuner either HP or EFILIVE--You must have patience and old sch engine knoweldge and know your way around a computer--and enjoy "tinkering"

 

Thank you tashspop. May I ask what is a "zip tie" mod?
My car has the auto trans so that diablo may be of use.

 

Basically, this:



Google it for more elaborate set-ups.

 

yep just like the picture, i believe there is a sticky on this forum. just remove half of factory airbox and apply zip ties. took all of about 5 min. to do for me. i've seen dyno claims and it makes sence looking at the setup, but once again like the handheld tuner i didn't get much if any seat of pants power boost.

i only chose this option because of easy cost and my car is a weekend cruiser and will avoid rainy days. i have paper filter in mine still too.

 

Thank you Bill, sincerely appreciate the info for these mods!
I'll try a ram-air system very soon and a handheld tuner to tweak the auto tranny. Really looking forward to further enjoying my ride. Corvetteforum rules!
mark

 

If its an A4 your first upgrade should be a stall.

 

my advise in order

1. CAI
2. Headers (mail order tune)
3. Heads/Cam (dyno tune)

 

Stall converter? I wasn't planning to make major engine upgrades, maybe 20-40 hp would be enough I think. Recommendations on a type? And is your stall recommendation based on getting better performance, trans service-life, reliability, or ?
Been many yrs since I had a performance car with auto trans, and that one I installed a B&M shift kit---crisp shifts for sure!
Thanks for any assistance or comments.
mj

 

I would never reccomend a mechanical shift kit on any computer controlled trans--You are just asking for trouble--besides all the firmness you would ever want can be done with trans tuning
As far as reliability with a stall-- Should not affect life at all IF you add an aftermrket oil cooler and keep an eyes on fluid temps ( under 200*) is best
If you are unfamiliar with how a stall converter works
simple explanation is that a a STOCK converter has a stall of around 1200-1400 RPM's --so when you floor it the converter slips up to the stall rating where it stops slipping and is spinning at the same rate as the trans INPUT shaft ( 1:1 )
A stock LS1 may only have 75 RWHP at 1200-1400 RPMs so when you launch thats all the power you have--HOWEVER with a higher stall like 3000 --when you floor it it slips up to 3000 and starts spiniing at the same rate as the input shaft now at 3000 RPM's -AND now at 3000 RPMs's your engine is making maybe 200 RWHP at launch rather than 75!! tripleing your launch HP-----and you haven't touhed your engine !!

 

Thank you TBLU92. Greatly appreciate the advice and certainly a higher perf stall will be on my shopping list. As a newbie to these cars (my last performance car was a late 80's mustang 5.0 stick), I'm reading all I can here to get smart and take a planned approach to the mods to keep it reliable and not trash the gas mileage too much. You experienced guys are sincerely appreciated!
mark