GenVibe - Community for Pontiac Vibe Enthusiasts

I've read a few times about a low rpm torque increase on the 04 GT. Purely anecdotal for me as I can't find any concrete info on this. It does makes some sense since if the intake or exaust is a bit more restrictive with the air pump, an increase in torque off idle should occur with a loss of torque and HP at higher rpm. Sort of the anti-CAI. Performance wise it should still be a little worse since the car will rarely be below 3k when driven vigorously but perhaps it's slightly better as a daily driver in stop and go traffic. Anybody have real info on this?

no, I have not read anything about this..it does seem silly to me since this 2zz motor was designed with high end in mind...did you hear about the Lotus Elise coming out???It has the same 2zz and 6spd tranny in it...they say that there are no real low end torque issues in this car because it ways less than 2klbs...Its rwd and seems to be the upgrade from the toyota mr2....only thing is, it costs around 40k...so all you need to do is cut about 800lbs from the gt , and your there!

What was the purpose of adding the air pump for the '04 models anyway?

Pollution. There's a 7 HP loss due to it. The cams haven't changed so there would be no other reason to loose HP. I just brought this issue up because there are posters that think that their 04 GTs are better because of the low end torque. Seems like rose colored glasses to me but I thought the board should get the correct info if available. I've looked and can't find a thing about it except lower overall numbers.

Faultline, You bet I heard about the Elise. Looks like they actually did get more midrange juice and power in general by not using the Toyota ECU and doiing their own intake, exaust and fuel curve. Kinda what we can expect from the unichip. It's probably less tolerant of regular gas which shouldn't be used in the first place but we've all heard the 'I used regular in my GT' stories. Lotus is probably more informative with their clients and figures their customer base to be a bit more knowledgeable. They are not protecting themselves from the lowest common denominator be it salesman or customer.

LOL.....when I bought my GT, my saleslady flat out told me to use regular gas. Unfortunately (before I knew about having to use premium), my first tank was regular . I say... NEVER AGAIN! Jim

Quote, originally posted by Kissfan79 »LOL.....when I bought my GT, my saleslady flat out told me to use regular gas. JimSame here Jim. Except I had a salesman.

Hi Goodvibe...Soon after the Pontiac site added the info for the '04 model I remember people here making comments about the drop in HP. I could have sworn I saw where the GT had something like 147lb-ft of Torque. I didn't post anything because I figured someone who knew more about it would. I remember seeing it twice on their site but now it's 127 lb-ft BUT I do notice it's achieved at 4400 rpm where the '03 is 130 @ 6800. Not much different but I'm sure the 127 at a lower RPM has to be somewhat better, right? Got that from the Pontiac site.Dave

Quote, originally posted by goodvibe »Pollution. There's a 7 HP loss due to it. The cams haven't changed so there would be no other reason to loose HP. Thanks. That's what I was figuring. Didn't they learn anything from the "smog pumps" in the 70's and 80's? They sucked! Why are they sticking them on the Vibes now? I just had my emissions test a few months ago and my Vibe blew zeros on both parts of the pollution test. Why did they have to go and screw with this? It doesn't make any sense! As Cartman would say: "godd@*n tree-huggin' hippies!"

i'm waiting for the unichip to come out any day. just holding out for a little while longer... besides, snow and ice on the roads so can't really test it out too much.

I missed that the torque peaks at 4400 rpm. Thats not a bad thing since it is about 3 more than it put out at that rpm last year. Good tune but hardly anything to crow about since the pump also adds weight and adversely effects the top end more but it's picking nits. I'm sure there's not much difference between the model years in use. They both feel like 2ZZs which is kinda special.

The air pump is electric, so the crank doesn't turn it. The air pump doesn't cost power. 04 VGTs & the XRS twins use a different calibration than the 03 cars.

We all know it's not crank driven or a parasitic loss(it's far away from the motor). It's part of a pollution control system and recalibration that causes a 7hp and 3lb torque loss. With the same cams, there would be no reason to loose any power with a recalibration to increase low torque unless something else was involved. It would only be positive improvements.

I think the big question here is........can it be taken out!

Now that's my kind of thinking!