Why are modded grand ams' so slow, when modded?

[SilverGAGT04]

Alright, bear with me a second. I just came from owning a GMC Sonoma. It was a 1999 GMC SONOMA 4X4 (Xcab) and stock it ran a 17.7at 74.2 mph. After an IAT mod, MAF mod, TB mod, TB spacer, 160 degree thermostat, Gibson exaust, Backyard intake, Headlight removed, Hypertech PP3, Casper TPS controller, Corvette servo, MSD coil, E-fan, ASP power pulleys, and EGR mod I got it to run 16.451@81.27. That is a 1.249 second loss and a 7.07 mph gain. Maybe I am thinking of this the wrong way but I thought that a lighter car with simple bolt-ons would duplicate the same result but it don't seem so to me. Don't get me wrong, I am not knocking the car. In fact, I love my car. I just don't want to have to take that long to get into the mid 14's. What is your guys opinions?

[99GrandAMSE]

Interesting ... I don't have as much as you done to my car and it ran almost 7/10ths quicker ... what altitude are you running at?

[MagusXIII]

It could very well be the tune of the engine. Your GAGT is brand new so it will be in the best state of tune. How was your Sonoma running before the mods? Was it tuned up?

ALso, consider the performance of the engines themselves. The 3400 is already more performance oriented than the Sonoma's engine. The parts you replaced on the sonoma were probably pretty restrictive on their own while the 3400 is already a better breathing engine with a more performance oriented ECU. So such mods do not yield the same gains as your sonoma.

Consider the Integra Type R. That engine was tuned to its maximum n/a potential. Everything that could have been done was done at the factory. That is why those engines do not respond as well to minor bolt ons such as exhaust and intake mods. Yet a domestic n/a sport compact like the Cavy Z24, the ZX2 I own, and the n/a neon, show better gains with the same type of bolt ons.

[DEMonte1997]

sounds like you went too far with the modding. as was previously said, most parts that come with the 3400 are fine as is. to run consistent low 15s and high 14s in a GAGT i would install a full cat-back exhaust and throw in a fender-well CAI. that alone, if done properly, should get you there.

perhaps you can try de-modding incrementally to see where your biggest power differences lay.

[matts]

but also don't your brand new engine have to kind of break in a little bit before it starts running it's best? that's what i've always thought anyway

[2002GT]

Originally posted by DEMonte1997
most parts that come with the 3400 are fine as is. to run consistent low 15s and high 14s in a GAGT i would install a full cat-back exhaust and throw in a fender-well CAI.


maybe i am reading this wrong, but CAI and Exhaust will not get ANY GAGT in the 14's

[Artic]

I have heard of low 15's from cai and exhaust thats on very few cars tho

[SilverGAGT04]

The truck was in perfect tune. The altitude is near 715 feet above sea level.

[92CamaroRS]

Originally posted by matts
but also don't your brand new engine have to kind of break in a little bit before it starts running it's best? that's what i've always thought anyway
a motor only needs about 30 mins before it is truly broke in. that is all the longer it takes for the rings to seat and the cam to break in. anything after that is bs.

[vdgmcool]

Yeah I don't think any exhaust and cold air intake will get you in the 14s but thats just my :penny:

[2002GT]

^ not 2 cents... its the truth lol

[Pte Socks]

hehe up here where the times are calculated, im hoping for a 15.5 in my car with a cat-back and CAI. I would need headers and a 62 mm TB to run high 14's at absolute best, more or less, low to flat 15's.

[TA^Guy]

Originally posted by SilverGAGT04
Alright, bear with me a second. I just came from owning a GMC Sonoma. It was a 1999 GMC SONOMA 4X4 (Xcab) and stock it ran a 17.7at 74.2 mph. After an IAT mod, MAF mod, TB mod, TB spacer, 160 degree thermostat, Gibson exaust, Backyard intake, Headlight removed, Hypertech PP3, Casper TPS controller, Corvette servo, MSD coil, E-fan, ASP power pulleys, and EGR mod I got it to run 16.451@81.27. That is a 1.249 second loss and a 7.07 mph gain. Maybe I am thinking of this the wrong way but I thought that a lighter car with simple bolt-ons would duplicate the same result but it don't seem so to me. Don't get me wrong, I am not knocking the car. In fact, I love my car. I just don't want to have to take that long to get into the mid 14's. What is your guys opinions?
ok lets see how I can explain this the best I can...

Not all motors are going to respond to modifications the same. A CAI on your truck might net 15hp and on a GA 10hp. Also when talking about incress power from a modification we should not be talking 'hp' numbers here, instead '%'. Example, two '00 Grand Ams with 3400 V6s. One bone stock, the other has a cat back exhaust, headers, IAT resistor mod, descreen throttle body, and some ignition work. If you slap a CAI on both of these cars the power incress will not be the same. The stock one will of course have a smaller gain than the modded one. I always hear people say "a CAI will give you 10hp", when in fact they should really be saying "a CAI could give you up to 10%." Also notice when companies use the 'up to' term. Meaning a stock motor will probally not get anywhere near that gain.

Now why did you truck respond to mods better than the GA? It's very possible the truck is simply strangled with restrictions from the factory, more so than the GA. So say the truck is putting out say 70% of possible power from the factory it's possible that another vehicle is putting out 85% making it harder to improve apon.

Shoot, look at the Buick Grand Nationals for example. Slap a high flow air filter, 3" exhaust, and a new PROM chip and you could easly drop a whole second in the quarter mile. Take a Corvette of the same vintage, say '87 for example, do the same mods and you might see a half a second improvment.

In summery, of course the motor in the truck is going to have more power. Towing, hauling, thats what a truck is for. But when you take Pontiacs best selling family car, I'm sure power wasn't at the top of the list when they designed it.

[DEMonte1997]

Well.. you guys know your GAs better than I. Even still, I'll stand by what I said. I've heard of many stock GAGTs running mid to low 15s. That said, I can't see why adding full exhaust and a decent intake wouldn't get you into the 14s. Oh well. Maybe add some headers if you need to. :lol:

[matts]

you could put some NAAAAAWWWWWZZZZZZ on it and run 9s :D......nothing else. just NAAAAAWWWWWZZZZZZ and some stickers.........and maybe a park bench :lol:

[SilverGAGT04]

No spray for me. I want to keep the car n/a. I don't know what to say but I will start the mods in about april. I am going to start with a low temp stat (180), ported and gasket matched upper plenum, a ported and gasket matched TB, an IAT mod, MAF mod, and an EGR mod. Oh, and I will start to run Mobil 1 0W30 oil. Maybe I will work on that "Ram Air" intake as they call it. With out running the car stock but assuming the "stock" time these cars get (4 door GT) and the stuff that is going down in, I figure about April, what do you all project the ET and MPH to be? I am figuring about a 15.3@89.

[30thAnnGAGT]

Well what gets me about the GA's is that each block is going to respond to mods differently. I could put the same parts on 10 different blocks with the exact same mileage and break in patterns and get 10 different results. When these blocks are sonic tested each comes out differently. Meaning each engine has x amount of potential.

Grand Am's are admittingly more street cars than they ever will be track cars. It doesn't mean I don't want to get a GA to hit low 13's or perhaps even 12's one day. But, each car will respond differently to different mods. Some may have to work harder than others to get to the place they want to go.

The sky is truly the limit with these cars. It's all about how much money you want to dump into the 3400 to make it go fast :)

[BBT]

I think John pretty much hit it on the head when he said the manufacturers use the term 'up to' to show increases. And I believe they mean their increases are taken in isolation, on a stock engine, not one with other mods. Do one mod, and you have improved your car. The next mod may not show as much increase as expected, because you have already enhanced your car with the previous mod. And so it goes. I believe The Old Guy once stated that he would check his changes after each mod to see exactly what gain that mod would give. Mods are not incremental - meaning that if one gives 10 hp, the next 5 hp, the next 3, that you end up with a total change of 18 hp. But all those mods together will still be worthwhile, as they make the car better overall.

[kubiache]

Originally posted by SilverGAGT04
No spray for me. I want to keep the car n/a. I don't know what to say but I will start the mods in about april. I am going to start with a low temp stat (180), ported and gasket matched upper plenum, a ported and gasket matched TB, an IAT mod, MAF mod, and an EGR mod. Oh, and I will start to run Mobil 1 0W30 oil. Maybe I will work on that "Ram Air" intake as they call it. With out running the car stock but assuming the "stock" time these cars get (4 door GT) and the stuff that is going down in, I figure about April, what do you all project the ET and MPH to be? I am figuring about a 15.3@89.

Ok, for starters, do you already have an exhaust or are you completely stock like it says? Every has their own opinions about what works best, but the vast majority of people here will agree that a cat-back is the place to start, followed by a CAI (stock ram air is nonsense). A lot of those mods you mentioned will do little to nothing for you without preceding them with other mods.

CAI, headers, and SLP could get you into the 14s. I think there's a red SE on here that pulled that off. ;) And he's very happy with where he is right now.

[SilverGAGT04]

My car is stock, not "stock". There are no modifications to it at all. I understand I/E is the place to start but I have low cash flow now so I was going to do all the little things that contribute to fast times with big mods now. That way when I get cash for SLP stuff, it will give an even bigger increase. I am my own engineer so I believe I can make a functioning "ram air" from what the factory started with. I am not new to modding cars or racing but only to modding and racing the GA's. I hope you all dont think I don't know what to do but I am just asking all of this to start because, like my point to this thread, all cars react to certain mods differently. I knew how my truck reacted to mods and I noticed that GA's are way, way different. I thank everyone for the information that was handed to me.

[Old Guy]

Originally posted by SilverGAGT04
No spray for me. I want to keep the car n/a. I don't know what to say but I will start the mods in about april. I am going to start with a low temp stat (180), ported and gasket matched upper plenum, a ported and gasket matched TB, an IAT mod, MAF mod, and an EGR mod. Oh, and I will start to run Mobil 1 0W30 oil. Maybe I will work on that "Ram Air" intake as they call it. With out running the car stock but assuming the "stock" time these cars get (4 door GT) and the stuff that is going down in, I figure about April, what do you all project the ET and MPH to be? I am figuring about a 15.3@89.

What you're describing as mods won't yield much in the way of added HP. The plenum and TB PnP won't do much without a CAI or reworking the Ram Air (hope you can do something to help it, so far no one else has been able to) and without PnP intakes it won't do much even then. You definately need to replace the exhaust cat-back.

Just a heads up.....180 degree thermostat isn't going to help without a fan override, IAT mod is worthless, EGR mod...questionable. If you can knock .1 seconds off of whatever you run stock with what you said you're going to do, you'll be doing good!!

Rule #1-----HP doesn't come cheap.

[92CamaroRS]

Originally posted by Old Guy

Rule #1-----HP doesn't come cheap.

my favorite saying is "How fast do you want to spend!"

[2002GT]

tru.... no offense, but it just erks me when people complain that their grand am is slow, and they wanna make it fast... for god sakes i hit a 14.9 with around only $500-$600... People you can't expect to be fast and do CHEAP mods...

[jayhawk]

Very true...I spent over $300 to get approx. 10 WHP.