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View Full Version : My build thread for the GXP



nino@gaypontiac
04-03-2009, 09:41 AM
Ok, so as you all know by now, I have a G8 GXp in Liquid Red with M6 and Onyx interior.

This vehicle has plans and I have alot of work I am doing to it.

Lets start with a pic of the car itself. and some background
http://i38.photobucket.com/albums/e141/jetfan8178/100_0634.jpg

The GXP was a car I wanted from first discusson of the equipment and price but became an afterthoiught initially when I had heard the new Camaro SS was to be lighter, more powerful and start at near 30k. Eventually, the truth came out and I learned that this near 30k number for for what is basically going to be a stripped down car, great for a single purpose car, but not for the all around street machine. So I decided to take this car after a customer backed out.

Initial impressions brought me to believe that this was the angry Pontiac. The new sibling in a long line of poorly advertised and mismarketed vehicles that promised excitment and never truly delivered. This car was not the same. The tame smooth and comfortable ride quickly changes to a shove into the seat from the extremely responsive throttle and a healthy growl from under the hood. This car does not look back at nearly 3 decades of piss poor supposed performance sedans and simply makes its own statement. If the car could talk it would say the long enjoyed bumper sticker phrase. "Get in, sit down, and shut up". Having owned and M5 I can see the comparisons that are made and yet, I feel that this vehicle outperforms the M5 in several categories most importantly the driving experience. I am very happy about my purchase. More to come.

nino@gaypontiac
04-03-2009, 09:42 AM
Dyno results!



Today was the day for baselines. I started at 9am on a trip to Strcitly Performance and their dynojet dyno and found myself in a sea of Mustangs and Ford Trucks. I told the owner it was great to be at a shop that was so involved in the Chevy community. He followed up with asking if the car was FWD and I answered no. He strapped the car to the dyno and away we go. First pull after the 30 minute drive... 357whp and 364 wtq. Not bad but not what I expected. Hey, its stock right...Another immediate pull netted a lower figure of 355whp and 362 wtq. and a 11.25afr which seems a little rich to me for a N/A car, but what do I know. I have only tuned about 200 turboed cars?? Ok, so we did a 15 minutecool down before the next and final run and I finally got what I expected... 365whp and 369wtq and followed by an immediate second pull of 361whp and 365wtq and some 11.5 afr's.

Video of the 3rd and best pull
http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/th_100_0669.jpg (http://s38.photobucket.com/albums/e141/jetfan8178/gxp%20build/?action=view&current=100_0669.flv)

Chart of 3rd run
http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/scan0001.jpg

Chart of all 4 runs
http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/scan0002.jpg

My best guess is that everything I heard was true. This vehicle is limited by tempurature. Something that I can easily solve with some tuning, a T-stat and some real coolant. Overall the results are pretty satisfying. There isn't much in this price range that makes this type of power to the wheels. I will update with track times this evening.

nino@gaypontiac
04-03-2009, 09:43 AM
bookmark

G8GXP4now
04-03-2009, 10:12 AM
The best part of that story to me was when he asked you if the car was FWD!

Are you gonna get some 1/4 times before you mess with the tune?

nino@gaypontiac
04-03-2009, 12:26 PM
Leaving my house in an hour to go to HRP ;)

Ill post the results when I get back.

I wish I had a set of slicks to throw on it for a couple of good 60 fts. I almost want to pull the fronts off my camaro with the 285 Kuhmo XS's and try them on the back of the car. LOL

confused2much
04-03-2009, 12:31 PM
Car looks great Nino! Good luck with the 1/4 mile times, hope you get some good traction. Can't wait to check back and see your times.

'02 ws6
04-03-2009, 01:15 PM
Cool thread so far. Good luck @ the track, I for one would try the Kumhos, anything wider than the laughable 245:) I just want to see a stock one reach the 12s. Hopefully you might be the one.
BlackBerry8830/4.2.2 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/104

nino@gaypontiac
04-04-2009, 07:35 AM
What did we learn today at the track?

Well, a couple of things.

The first one is that I am way out of practice. Having driven AWD cars for the last 8 years has not helped my skills with RWD at the track.

The second one is that 245 all seasons are not the correct tire for this car.

Launching was an adventure. Go easy and it bogs, go hard and it spins, try to slip the clutch and I fry it. LOL Not a great day.

Ultimately, the result was a best run of 2.17 60' 13.60 at 105.84.

Not impressive by any means but considering this was the very first run, I bogged on the launch an d missed third, There is plenty of room here.

The more enjoyable run was the hard launch attempt that netted me a 2.45 60' and 14.41 at 104.23 that made me think the car was going to fall to pieces from the wheel hop.

Ill continue my post in a little while. Busy at work right now...

Ok, the rest of the details.

Weighed the car with me in it... 4275lbs.

Not really light by any means, but what can I say, its a bigger car than it looks like. I will try to get that down as well.

nino@gaypontiac
04-10-2009, 07:35 AM
The headers are installed!

I went with SLP Longtubes with high flow cats. The fact that they are direct bolt on's to the factory system and come pre-coated was my major reasoning behind choosing these.

I realize they are not as large as kook's but frankly, I dont think I need anything any bigger. These should do just fine for what my plans are.

They look great, fit great and should make a very nice difference.

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0700.jpg

Plenty of clearance in every single direction. They may as well have been factory.

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0699.jpg

Lined up with everything just as it was supposed to. No bending, prying or hammering.

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0698.jpg

Everything needed is included and no welding required!

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0697.jpg

They even came with factory GM gaskets which is a plus. I hate to deal with leaks and dont expect any here.

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0696.jpg

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0695.jpg

Ill post some sound clips and vids later today.

vic2186
04-10-2009, 07:42 AM
looks killer...try to feather the clutch just to get it rolling then give it some gas..i had a 600hp sr20det that spun 3 gear on the highway..ran 10.89 with ac and a 10 woofer in the back..american clutch cars are a little lighter than a stage 5 unpucked kevlar lol...i think you can get her down to 12.90 on stock tires if you keep practicing..try running in a area where theres no cops and pratice launching out of 1st for like 30 mins.with clutch rest lol..you will master it..

confused2much
04-10-2009, 09:24 AM
Headers look great, I bet they sound good too.

-Ray-
04-10-2009, 11:32 AM
Looks great. Keep an eye on the spark plug wires. Some have reported burnt wires with SLP's.

nino@gaypontiac
04-10-2009, 05:51 PM
2 wires are close at the base, too close. Easily fixed with some teflon shielding.

Sound clips...

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/th_100_0704.jpg (http://s38.photobucket.com/albums/e141/jetfan8178/gxp%20build/?action=view&current=100_0704.flv)

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/th_100_0703.jpg (http://s38.photobucket.com/albums/e141/jetfan8178/gxp%20build/?action=view&current=100_0703.flv)

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/th_100_0702.jpg (http://s38.photobucket.com/albums/e141/jetfan8178/gxp%20build/?action=view&current=100_0702.flv)

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/th_100_0701.jpg (http://s38.photobucket.com/albums/e141/jetfan8178/gxp%20build/?action=view&current=100_0701.flv)

Completely stock with headers.

Can't wait for the axlebacks.

Adam
04-10-2009, 06:26 PM
sounds great!

nino@gaypontiac
04-12-2009, 10:04 AM
Did a couple of the "free mods" today...My own versions.

First, I modified the intake snorkle. Sorry, no pics as I hate crawling under the car on jack stands ad it was tighht. Needless to say, It should breath alot better. I also took my heat gun and modified the lower plastic covers into a small scoop to redirect some cold air into the fender for the intake to breath. Hopefully it can create some extra HP up top. It may need a little more molding to be perfect, but not bad so far.

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0715.jpg

Then, The hood scoops. I wanted to make them into more of a underhood heat solution so I modified them to push cold air into the engine bay and hopefully push the hot air out from behind the radiator and under the car (the way a corvette essentialy works)

So heres what I did.

Pop off the rubber
http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0705.jpg

Remove scoop piece, as you can see its blocked off
http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0706.jpg

Remove blocking plate
http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0707.jpg

Freedom! It can flow now
http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0708.jpg

Under the free flowing scoop reinstalled
http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0710.jpg

Reused the blocking plate as a diverter to divert air into the engine bay. It snapped into position like it was supposed to and fit perfectly. I may add a dab or two of silly putty to make sue it stays in place.
http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0711.jpg

To the naked eye, looks like normal
http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0712.jpg

I then trimmed the rubber parts to open them up as well.
http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0713.jpg

and reinstalled them. All done
http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0714.jpg

Will it do what I want, who knows. But I prefer making a scoop flow airover making it useless. Next will be the intake manufold lower cover, but that will be when its not raining.

nino@gaypontiac
04-14-2009, 12:32 PM
SLP Axlebacks came in today...and went on today



They fit like a glove, just as good as the headers whih I expected. The tip, which was my main reason for choosing this set looks perfec in the openings and in my opinion more OEM than OEM.



The biggest bonus however was when I started the car...Needlss to say, you need to hear it for yourself. Im in love. The perfect cross of Muscle car and euro performance car is the only way to describe it.



Im so happy with the sound I am uncertain if I want to tamper with the midpipe now. Next, dyno, tune and then back to the track to see if I can embarass myself any worse. :p



SLP kit

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0716.jpg



OEM, I wonder if I saved any weight?

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0720.jpg



Installed

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0719.jpg



Sounds



http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/th_100_0717.jpg (http://s38.photobucket.com/albums/e141/jetfan8178/gxp%20build/?action=view&current=100_0717.flv)



http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/th_100_0718.jpg (http://s38.photobucket.com/albums/e141/jetfan8178/gxp%20build/?action=view&current=100_0718.flv)

G8GXP4now
04-14-2009, 01:49 PM
Did the dealership lose your plates? That tag is expired!

Car sounds real nice. How does she feel? How is interior noise compared to stock? Have you done any tuning on it yet?

nino@gaypontiac
04-14-2009, 04:58 PM
LOL, no, Im just too lazy to put them on. Plus, Ive been driving the camaro cause its been so nice out.

Car feels awesome. A huge seat of the pants difference so far and no tuning yet. Im hoping to get that done this week before the dyno day.

I drove the car a bit on the highway and surprisingly, the interior seems even quieter. Its really strange to me, but no drone and no noise at all.

cowbiker
04-19-2009, 07:55 AM
Love hearing the gulls in the background on the last clip. ;-) I went with the same axle-backs b/c I felt the tips complimented the rear valence so well.

UGotSmkd
04-20-2009, 07:31 AM
Did you ever get the car tuned before the dyno day yesterday?

GTPprix
04-20-2009, 07:40 AM
How much powa~!?!?!?! :D

nino@gaypontiac
04-20-2009, 09:11 AM
No, we just put it on there with the OEM Tune.

Made 375/375.

Of coarse, totally different dyno. I imagined the dyno at Strictly performance may have been a little high but either way, tuning is needed. The car is running overly rich by quite a bit.

G8GXP4now
04-20-2009, 10:49 AM
Your baseline dyno used STD as the CF.

ICON used SAE. How much of a difference does that make?

nino@gaypontiac
05-09-2009, 01:31 PM
Got my Roto-Fab account and ordered a handful of intakes and now I have one on my car. (and several sitting here)

I must say, perfect like OEM fitment, Great instructions, and the quality is awesome!

Let me add... The sound is an added bonus as well.

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0746.jpg

Tuning should be done on Thursday. Hopefully I can break the 420 mark ATW.

nino@gaypontiac
05-14-2009, 05:26 PM
Okay, so I got a reasonable tune complete today.



Is it up to my standards, maybe not, but it did the job and got me over 400 ATW. I feel as it there is alot left, but time more than nything limited what I could get done and my inability to get the components I needed from HP Tuners myself forced me to have it done by someone else.



Car feels much stronger across the power band and I think the IAT's have alot to do with the fact that we didn't get as much as we expected from it. A little more work could make it easly over 420 IMHO, but Im just not that interested in fumping hundreds of dollors into tuning when I know Im going Maggie.



So, heres the chart.



Dyno'd at the same place I got my baseline done.



Baseline was 365 ATW and now before the tune we have 382 with a rotofab, SLP 1 3/4 headers and SLP axlebacks. Not bad.



After Tuning, 402 ATW



The strongest pull on video

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/th_100_0749.jpg (http://s38.photobucket.com/albums/e141/jetfan8178/gxp%20build/?action=view&current=100_0749.flv)



The dyno chart. Pre-tune and tune pulls.

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/scan0001-1.jpg



I also attribute a good portion of the lower than expected numbers to the factory midpipe and small Cats included with the headers. But that will all be corrected with the Kooks setup. ;)

nino@gaypontiac
05-21-2009, 04:41 PM
CTS-V wheels are installed!



and the best way I can put it is, Im tired. ;)



http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0756.jpg



http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0758.jpg



http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0764.jpg



Traction is a good thing!

68fbird
05-21-2009, 05:29 PM
Subscribed. Great post.

01350ta
05-21-2009, 06:56 PM
Good job. Your car looks great & sounds really good.:thumbsup:

g8gxp
05-21-2009, 08:53 PM
1 3/4 pipes? aren't the bigger ones more suited for FI?

Rican219
05-22-2009, 05:43 AM
OMGZ I want. I love the sound Whats next?

nino@gaypontiac
05-22-2009, 08:08 AM
Yes, I should have gone with 1 7/8 headers and will be doing so in the coming weeks by switching to a kooks setup.

I thought this would be enough but it seems even now I simply dont flow enough. :(

nino@gaypontiac
05-30-2009, 06:46 AM
OK, so I made it back to the track last night and got a couple of runs in before it was too busy.

Conditions were not great. Hot, Humid and a DA above 2100 but all in all it could always be worse.

First run was the best and it was so damn packed I only got 2 total.

2.05 60'
13.07
108.25 mph

Not bad.

The tires were a huge help. The car hooked right out of the hole and could have even done a little better.

My second run...I dont want to talk about...spin spin spin all the way to a 13.45

Car lacks top end.

6 tenths faster with only 3 mph more. But 12's are there I think even on just a better day.

JMH
05-30-2009, 06:43 PM
Thanks for the great read so far. I'm new to the domestic scene so bear with my noob question but I thought the 1 7/8" was for FI applications? If I read correctly you only have an intake and exhaust with a tune. I would have thought the 1 3/4" would be good for your current setup?

nino@gaypontiac
05-30-2009, 07:13 PM
Read more. ;)

FI coming soon!

nino@gaypontiac
06-03-2009, 07:46 PM
Rotofab radiato cover installed. Is there anything better? This thing is so close to looking stock its ridiculous!

http://i38.photobucket.com/albums/e141/jetfan8178/gxp%20build/100_0775.jpg

BigV8
06-04-2009, 09:18 AM
Nino, do you have an HSRK installed?

GTPprix
06-04-2009, 02:03 PM
That cover rocks, I need to install one on my GT now only have it on the GXP :\

nino@gaypontiac
06-09-2009, 07:32 AM
Not yet, I plan to do it in conjunction with my GMS 180 deg thermostat and Evans cooling coolant.