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Simple mods worth it ???

17K views 54 replies 30 participants last post by  Chrisco 
#1 ·
Hi all,
New to the forum and a new GTO owner (I've had it just under a week).
I'm wondering if anyone has any experience with some of the simpler mods, like the K & N filtercharger air cleaner conversion, or adding a Granatelli MAF
sensor. I realize both will give slight bumps in preformance, but are they worth the time/trouble???
Any thoughts ?
 
#2 ·
No expert here but in IMO less restrictive induction or more air is a plus but it depends how good or bad the stock intake is ! Maf replacement I don't think this does much unless you have a seriously modified motor! You can do a search on the corvette forum for maf replacement posts good or bad? same motor as 97 to 04 C-5 in your GTO :D

Robert
 
#3 ·
yes an aftermarket intake will help... not much but it will make it sound a little meaner. and it will give you a couple hp gain. larger MAF is for forced induction or N2O applications. if you want decent gains for an easy mod, go for aftermarket MANDREL bent exhaust and headers. another thing w/ the MAF is most of the time you need to have flow matched injectors that are calibrated for that particular sized MAF. something to think about.

and does anyone know if they are making a s/c for the GTO anytime soon?
 
#5 ·
Breath in, breath out mods for 2004 GTO

I am having a baseline dyno tomorrow. We are then installing the predator program in the PCM. Then another dyno. On Monday, the dealer is installling JBA headers, Granitelli MAF, 80mm throttle body, and cold air induction. The following Monday, back to the dyno. I will post the results.
 
#6 ·
Got my Predator today and played with it this evening. This car is so fast anyway I'm not sure if I can say it's any faster, but, I sure like the shifts. I now get third gear scratch without being at full throttle. I installed the pre-programmed 'performance' tune and then did a little modifying on the shift time, shift pressure, and upshift MPH & RPM. I'm a little disappointed that, even after modifying the shift times to not shift until I reach 41 MPH or 6,300 RPM, it still shifts to second quickly when I'm not putting much of a load on the engine. They should have put a manual shift on the GTO where you slide the shifter over to manual and hit it up or down to shift the gears yourself. The Predator comes with a 30 day money back guarantee but I can't imagine taking it back...I think it was worth the money.
 
#7 ·
Nice to see these performance threads :D


The small bolts will do small things in the hp world. IMHO it's best to save up for a real mod, like a head cam kit... Then you bolt on 100 hp in one wack, instead of 4 hp at a time.

Start talking to turner and pick their brain for ideas... then share.
 
#8 ·
GlennH said:
Got my Predator today and played with it this evening. This car is so fast anyway I'm not sure if I can say it's any faster, but, I sure like the shifts. I now get third gear scratch without being at full throttle. I installed the pre-programmed 'performance' tune and then did a little modifying on the shift time, shift pressure, and upshift MPH & RPM. I'm a little disappointed that, even after modifying the shift times to not shift until I reach 41 MPH or 6,300 RPM, it still shifts to second quickly when I'm not putting much of a load on the engine. They should have put a manual shift on the GTO where you slide the shifter over to manual and hit it up or down to shift the gears yourself. The Predator comes with a 30 day money back guarantee but I can't imagine taking it back...I think it was worth the money.
from what i understand the '05 or maybe later will have that tiptronic shift option w/ the ATX.
 
#9 ·
tbush said:
I am having a baseline dyno tomorrow. We are then installing the predator program in the PCM. Then another dyno. On Monday, the dealer is installling JBA headers, Granitelli MAF, 80mm throttle body, and cold air induction. The following Monday, back to the dyno. I will post the results.
what, no injectors? i can forsee problems w/ that. my friend put a larger MAF on his car and it would stall after a few seconds of running cuz his injectors weren't calibrated for that particular sized MAF. i could be wrong but i think its the same w/ all cars... i would like to know if im wrong though so any input would be cool.
 
#53 ·
DOH! as homer would say.

there is no such thing as injectors "calibrated" for a certain MAF.
A MAF measures MASS AIR FLOW and aftermarket MAF is generally sized bigger to stop pegging which is caused by forced induction. The stock maf is only sized to handle a certain amount of air flow/ hour and an aftermarket maf fixes that. Since both the stock and aftermarket MAF must be able to send info to the stock computer they have to be on the same set of outputs (0-5v) (0-12000hz). since stock is limited at say 75 lbs/min of air flow it sends out a 5v signal at that flow. The aftermarket equivalent must be able to handle up to say 120 lbs/min of airflow. So the aftermarket equivalent might send out a signal of say 3.9v for the equivalent 75 lbs/min. Without recalibration of the stock Airflow tables, the computer will give enough gas for whatever 3.9v was with the stock maf. thats why your friends car was leaning out hardcore
 
#10 ·
Predator results 2004 GTO

Ran the baseline dyno today. Results were 283hp/315tq. After five tuning runs,
we achieved 296hp/324tq. We noticed the factory timing was very conservative at 12 degrees. We change to a higher setting of 23 degrees. Air fuel ratio(AFR) was very rich, especially in the higher band (4000 and up). We leaned the mixture but left headroom for the Granatelli MAF, as it leans the high end also. Next week we are having the headers, throttle body, MAF, and cold air induction installed. WE will try another dyno after(Oct. 12 or later)

Terry
 
#11 ·
Performance results 2004 GTO

Forgot the most important part. A test drive after exhibited very nice shift characteristics. During the dyno, we noticed a horsepower roll-off at 5500, so we moved the shift points back a little. I believe this roll-off will be fixed with the headers and other breathing mods. Although not a great hp jump, the feel is great! Can't wait to finish the mods!

Terry
 
#12 ·
tbush said:
Ran the baseline dyno today. Results were 283hp/315tq. After five tuning runs,
we achieved 296hp/324tq. We noticed the factory timing was very conservative at 12 degrees. We change to a higher setting of 23 degrees. Air fuel ratio(AFR) was very rich, especially in the higher band (4000 and up). We leaned the mixture but left headroom for the Granatelli MAF, as it leans the high end also. Next week we are having the headers, throttle body, MAF, and cold air induction installed. WE will try another dyno after(Oct. 12 or later)

Terry
it dyno'd 65+ hp less than at the flywheel and 50 less tq? um... that sounds pretty rediculous to me... im mean, call me a dumbass but aren't whp #'s usually only about 10-20 less than flywheel hp #'s? or is that just w/ front wheel drive?
 
#14 ·
powder said:
it dyno'd 65+ hp less than at the flywheel and 50 less tq? um... that sounds pretty rediculous to me... im mean, call me a dumbass but aren't whp #'s usually only about 10-20 less than flywheel hp #'s? or is that just w/ front wheel drive?
Not all Dynos will give the same result. A "Dynojet" dyno will give you higher HP numbers than a "Mustang" dyno. I think the "Mustang" has a load on the rollers which would give you lower RWHP.
 
#19 ·
I put one in my GTO this past weekend. I know absolutely nothing about cars, but my GTO has inspired my to start learning. I got the K&N kit and was supposed to get help from a friend, but couldn't wait for him to get there. So I read the instructions, they didn't look to tough, so I dug in and got to work. I had it installed in 2 hours, and I would have to say that it is pretty easy if you can follow instructions.

Chuck
 
#21 ·
I looked all over online and called everyone I could find and none of them had it in stock. They all said it would be 10 days to 2 weeks before I got it. Being the impatient type, I found it here in town for $275 plus tax...about $20 or so more than online. I haven't picked it up yet but was promised it would be at O'Reilly by 4:00 this afternoon. I bought my Predator Programmer at O'Reilly and paid the same $420 I found it for online. I also got the front seat smokers package (ashtray and lighter) from my dealer and ended up having that installed...$165 to have a place to doose my nasty cigarettes :shutme . Now I need 18" wheels and tires, a cat-back system and a ram air hood and I'll be in heaven.
 
#24 ·
PJC_GTO said:
What did you have to pay for that unit?
After checking online and finding it anywhere from 259.99-399.99(K&N direct)
I saw one offered on Ebay for $229.00 + $12.00 S/H = $241.00 to my door.
I'm not a real "shade tree" mechanic and it took me about 25 min. taking my time to insure I didn't break anything. Had all the tools handy except a T-30 Torex socket, which added $2.99 to my total cost...I can live with that.
Now I need a granetelli MAF (set up for cold air induction) and a Diablo tuner.
THEN I'll get the ram air hood and 19"s, by then I'll probably need the tires anyway !!! :D
 
#25 ·
Ursus said:
After checking online and finding it anywhere from 259.99-399.99(K&N direct)
I saw one offered on Ebay for $229.00 + $12.00 S/H = $241.00 to my door.
The guy I got mine from offers one a week on Ebay, no bid just click the buy it now button. Search for 2004 GTO, or his seller name "Gforceautosports"
I am in not connected to this guy in any way, just info for those that want it.
 
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