The MW Automotive Thread 3.0

[David Hingtgen]

Took me 2 evenings to change the plugs and wires on my GTP (mainly because the wires would NOT COME OFF, not due to access, I spent 45 mins per wire on some---plugs were easy)----I don't know of anyone who's changed theirs on a GXP yet, even the guys with 05's. The real issue is the serpentine belt. It's apparently a "drop engine and subframe" operation. Though of course, the GXP is rare enough that a lot of places have no clue how to really work on them---kind of like how more than 1 dealership thought the only way to change the supercharger oil in a GTP (if they even believed it could/should be changed) was to take the entire s/c assembly off the manifold, hoist it up, turn it upside down, and drain it. I still need to buy the service manual for my new GP, as soon as I have 130 bucks to spare... I've actually thought about taking my car to the Chevy dealer for work, as they should have more experience with the engine.

As for modding--nope, my GTP remained stock, despite how large the aftermarket is for it, and how easy many mods were. I did replace a few parts with 2000/2001 parts, but nothing performance/engine-oriented. I only have one car, I need it to be reliable. And with the 07's having a 5-year/100,000 mile powertrain warranty---I intend to keep it bone stock so as to have any future issue covered without arguing about "mod-related failure".

Current mods for a GXP are few and far between---basically CAI and exhaust. A lot of people see the GXP as being "like a modded GTP, but with all the parts still under warranty". Going to watch oil consumption, see if it could use a GTO-style catch-can.

Here's 2 videos of a GXP's exhaust---while he does have flowmasters, I know his idle and revving sounds IDENTICAL to mine, so I don't think they changed the sound that much. GXP's have the exact opposite sound of a GTO on purpose---GTO's roar, GXPs burble. It's a very "thub-thub-thub-thub" sound. Part of it is that the exhaust has to be tuned for both V8, and V4 mode.

And a brand new video--autocrossing!

(Interesting that both of the ones on Youtube are stealth grey, as it's an 06/07 color only, and usually not as common as graystone or shadow grey---I'm the only stealth grey 07 I know of at ClubGP)

[areaseven]

That's an awesome GXP you got there, David.

Edited July 5, 2007 by areaseven

[David Hingtgen]

GXP, traded in the GTP for it. And thanks for the comment.

Might as well, here's my 99 GTP, photos taken hours before trading it in for the GXP. Many dealerships thought it was an 03 and only 4 years old, instead of being a 99 and 8 years old.

[emajnthis]

Nice GXP; keeping it stock is the way to go, pushing too much HP out of a FWD platform will just burn up your tires and give you torque steer, better to keep it quick and reliable.

[David Hingtgen]

Plus, the tranny is already "beyond maxed out" on the higher-power Grand Prixs. The previous version didn't like the 280lb/ft of the GTP. That's the weak link in the GTP, even stock ones burn them out. There were some changes in 05 plus the new fluid in 06 to get it to handle 323lb/ft in the GXP, but still---that's the #1 failure of the GXP as well. (Thank you 5-year powertrain warranty---I don't think I would have risked getting one without it)

[emajnthis]

It's a good thing there's a powertrain warranty, it's half tempting to purposely burn it up just before 5 years just to get the thing replaced. I remember EVO owners were doing the same thing since Mitsubishi started the 10yr/100,000 warranty coverage, and everyone knows how DSM tranny's crap out.

[pfunk]

Why isn't that technology giving us 300HP 40MPG engines?

Well, its all mathmatics. My 96LT4 got over 30 on the highway. An effecient gasoline engine burns at about 14/1 air to fuel ratio. GM has learned to lean out thier engines at highway speed to about 15-16/1 and the computor finds the perfect timing for the cars conditions at every startup (so if you drive in the mountains, its a good idea to shut off your car and restart so the timing program can run again. youll notice a huge diference at elevation). GM runs the show as far as engine effeciency ussing displacement instead of forced induction for the mainstay of motors they offer. People dont realize that smaller displacement 300hp motor requires just as much fuel and air as a 300 hp large displacement engine. some effeciencies are lost due to rotating mass or on a smaller displacement engines turbo or supercharger. After that, you deal with mass of the vehicle and at highway speeds aerodynamics. 300hp and 40 MPG is realativly easy,,, but are you going to pay the price for the same car that was steel and aluminum thats now carbon fiber and titanium and looks like a teardrop?

Watch out in the next few years about the EPA requirements on MPG's. thier talking 30+ for cars and light trucks. GM has allready ussed aluminum extensivly in the front of thier truck platform and gets about 18-20 on the highway. theyl have to reduce mass and increase aerodynamics at a cost to you, the consumer

[emajnthis]

Well, its all mathmatics. My 96LT4 got over 30 on the highway. An effecient gasoline engine burns at about 14/1 air to fuel ratio. GM has learned to lean out thier engines at highway speed to about 15-16/1 and the computor finds the perfect timing for the cars conditions at every startup (so if you drive in the mountains, its a good idea to shut off your car and restart so the timing program can run again. youll notice a huge diference at elevation). GM runs the show as far as engine effeciency ussing displacement instead of forced induction for the mainstay of motors they offer. People dont realize that smaller displacement 300hp motor requires just as much fuel and air as a 300 hp large displacement engine. some effeciencies are lost due to rotating mass or on a smaller displacement engines turbo or supercharger. After that, you deal with mass of the vehicle and at highway speeds aerodynamics. 300hp and 40 MPG is realativly easy,,, but are you going to pay the price for the same car that was steel and aluminum thats now carbon fiber and titanium and looks like a teardrop?

Watch out in the next few years about the EPA requirements on MPG's. thier talking 30+ for cars and light trucks. GM has allready ussed aluminum extensivly in the front of thier truck platform and gets about 18-20 on the highway. theyl have to reduce mass and increase aerodynamics at a cost to you, the consumer

also with turbocharged/supercharged vehicles they run at a really low compression ratio usually around 8 or 9 to 1 which means they need to squirt more fuel at the low end to compensate for the lack of compression. In modern turbocharged cars it is remedied with the use of direct injection and VVT which allows for higher compression of 10 or even 11 to 1 which is the current standard for most NA motors while still retaining high end boost compression giving them amazing MPG numbers. DFI is also being used in NA motors to provide better fuel consumption with higher compression ratios (11 to 12 or in some applications even higher) which is also providing the same benefits (though it's not quite as noticeable at the high end). The trade off between force induction and high displacement is similar to the argument between overhead valve and overhead cam, there's a lot of give and take on both ends and neither is better or worse than the other it's just about the application of each and what it's being used for. Normally you don't have a high performance car for gas mileage similar to why you wouldn't have a high displacement overhead cam motor to save engine space. Not to say that it's not possible, but it takes a bit more ingenuity, engineering, and more importantly (like pfunk said) money, and guess whose paying for it in the long run.

[pfunk]

I do like the VVT and DI, but I really dont see huge reliability in VVT because it relies on either a servo (moving a cam at the valves to increase or decrease thier ratio) or cylinoid that operates the valves (completly electronic). DI has been a proven technology in diesels (mechanically driven with high preasure and the electronics only on the low pressure part). The only complaint is that the wiring going to the injectors decays because of being internal (high heat cycles), but in thier defence in a gas motor is only made to run 100-150K which is about the time they ussually go in a diesel(so VVT will have the same problem). In my buddies truck, he has replaced the harness for the injectors 2 times in 275K miles. Personally I see diesels making a huge impact on automakers since they are 40% more effecient then gasoline motors. its just that a low compression turbo diesel is still about 18:1 and you need big mass in the motor to contain all tat pressure

[emajnthis]

I do like the VVT and DI, but I really dont see huge reliability in VVT because it relies on either a servo (moving a cam at the valves to increase or decrease thier ratio) or cylinoid that operates the valves (completly electronic). DI has been a proven technology in diesels (mechanically driven with high preasure and the electronics only on the low pressure part). The only complaint is that the wiring going to the injectors decays because of being internal (high heat cycles), but in thier defence in a gas motor is only made to run 100-150K which is about the time they ussually go in a diesel(so VVT will have the same problem). In my buddies truck, he has replaced the harness for the injectors 2 times in 275K miles. Personally I see diesels making a huge impact on automakers since they are 40% more effecient then gasoline motors. its just that a low compression turbo diesel is still about 18:1 and you need big mass in the motor to contain all tat pressure

Yeh i know what you mean about VVT, especially when you get into things like intake VVT exhaust VVT and lift control, you're looking at a maintenance nightmare which is why as efficient as it can make things in terms of low end emissions, efficiency, and power, it provides lots of maintenance troubles, engineering, and labor. Like you said DI has been around forever in Diesels and only recently has it hit main stream with gas motors; in fact most of the DI gasoline motors are the original gasoline motor with a DI head stolen from one of the motors in their diesel line up (BMW & Audi are guilty of this). The only companies interested in some shape or form of bringing performance to the diesel market are German companies it seems; American companies associate diesel with trucks and tend to keep it that way, and try to go main stream with hybrid tech which i still think is a technology that wasn't maturely and thoroughly thought through.

[pfunk]

American companies associate diesel with trucks and tend to keep it that way, and try to go main stream with hybrid tech which i still think is a technology that wasn't maturely and thoroughly thought through.

talk about a maintenance nightmare, not to mention cost, electric or hybrid puts shivers down my spine.

Speaking of VVT my wife LOVES the new GMC acadia (it usses VVT) it costs 40+ for a loaded one and starts at 400 for lease WAY too much IMO. I refuse to buy a new motor like that, but it does have the 100K warranty

[emajnthis]

that DOHC 3.6Liter VVT motor is pretty awesome, i'm not sure if they've done it yet, but they're actually supposed to give that motor DI too; you might want to look up the motor specs for the 3.6 in the Acadia to see if they've done that already, it might be the reason the damn thing is so expensive. You get a GM discount anyway though, so i'd imagine it can't be that bad after discounts.

[pfunk]

that DOHC 3.6Liter VVT motor is pretty awesome, i'm not sure if they've done it yet, but they're actually supposed to give that motor DI too; you might want to look up the motor specs for the 3.6 in the Acadia to see if they've done that already, it might be the reason the damn thing is so expensive. You get a GM discount anyway though, so i'd imagine it can't be that bad after discounts.

yeah, that was after GM employee pricing

It only has VVT for the time being, but for a 8 passenger "van" that weighs in at 4700lbs curb it gets 18/26mpg. They really ned to reduce the mass on thiese cars and trucks, then you will see some impressive numbers. Hell, people think that old cars are heavy. Heres some food for thought. A 1970 chevelle weighed in at about 3300 lbs with no options. My wifes old 2 door grandam weighed in at 3400lbs somethings wrong with all this content in cars today

[emajnthis]

yeah, that was after GM employee pricing

It only has VVT for the time being, but for a 8 passenger "van" that weighs in at 4700lbs curb it gets 18/26mpg. They really ned to reduce the mass on thiese cars and trucks, then you will see some impressive numbers. Hell, people think that old cars are heavy. Heres some food for thought. A 1970 chevelle weighed in at about 3300 lbs with no options. My wifes old 2 door grandam weighed in at 3400lbs somethings wrong with all this content in cars today

That's what i've been saying, our motors are getting lighter and more powerful and yet the cars are still weighing in at 3500lbs, somethings not adding up right. Also i looked it up, DI is supposed to kick in sometime next year and goes into the Cadillac and something else (Sky/Solstice? i wasn't really paying attention to the article) and push the 3.6L to 300hp with better MPG numbers.

[Beltane70]

That's what i've been saying, our motors are getting lighter and more powerful and yet the cars are still weighing in at 3500lbs, somethings not adding up right.

Could any of this excess weight have something to do with the much stricter safety requirements on today's vehicles?

[David Hingtgen]

Definitely, it's the main reason for the Grand Prix's weight increase over the past few years. Also I've seen rumors of the Camaro gaining 200 pounds between concept and final version, just for 2009 safety standards.

Anyways, back to engine efficiency: Any comments on GM's "shutting down 4 cylinders" like mine does? People who've tapped the computer say that when it happens, the fuel injector pulsewidth doubles on the remaining cylinders, so how is it really helping?

[emajnthis]

i understand stricter safety as a cause, but i think it has more to do with how manufacturers are meeting the requirements. Rather than reengineer the frame to be lighter and stronger, manufacturers are just adding steel braces and plates to make for stronger rigidity but lots more weight. And safety parts like Bumpers that could be made stronger with modern materials (that new foam crap) are just being reinforced with steel bars which is great and safe but cheaper and heavier. So i think for the general consensus of vehicles most companies are going to go cheap with saefty reinforcement as opposed to some of the sports cars like the vette which are getting the star treatment.

[myk]

Lol...

[pfunk]

safty requirements are the main reason cars weigh so much now adays. I remember working at GM and they did a study on how much cost and content airbags did to the car. the coat was about 6000-10000 per car and the added mass to keep the instument panel from coming apart during deployment was HUGE. some cars were introduced with a magnesuim I/P structure, but like emagin said, most stuck to the steel structure. It has allways been a competition with the insurance companies pushing safty standards down the FEDs neck and the EPA wanting cars with less mass. Another big contributor to weight is sound deadening. People want thier cobalt to sound and ride like a caddy and not hear the engine inside the vehicle. If anyone has played around with dynomat, they know how much that stuff weighs. Now with side curtain airbags thier adding mass to the pillars along with the head impact requirements everywhare (known as FMVSS 201) so along with adding structure to handle the airbag, you have to protect against that structure.

A little tidbit of info. if your not correctly seated in your car in the event of an impact (IE ol lady too close to the steering wheel, or "gangster" leaning on the side window) your as good as dead. If I ever get a car with side airbags, thier getting disconnected (yellow connectors in the I/P for shipping)

[David Hingtgen]

My car has the headliner-mounted side-airbags, and they do cause me a bit of worry. I have very little headroom as it is (waiting for seat to sink down a bit from use, then it'll be better). My head is way too close to the side airbags for my comfort at the moment. I'm not down low enough that my head will hit the side window glass anyways--my head will hit the headliner above the door---probably while it's trying to deploy.

Also, new Grand Prixs are a lot quieter than the old ones, noticed that instantly the first time I was in an 04. My V8 should be louder, but idling and cruising--it's actually quieter due to all the sound deadening. And you can even see the dynomat stuff in the trunk if you take out the carpeting--the old one had none of that.

[David Hingtgen]

Not sure which thread this should go in----they're making a production version of Ironhide:

http://www.edmunds.com/insideline/do/News/articleId=121589

[Pat Payne]

Not sure which thread this should go in----they're making a production version of Ironhide:

http://www.edmunds.com/insideline/do/News/articleId=121589

{whistles}

Now, how much are they gonna charge for the ultimate Transformers collectible?

[emajnthis]

uhh.... cool? Never really liked Ironhide, though i still haven't seen the movie either so i guess this doesn't really appeal to me on either side of the fence.

[Ghadrack]

I bought a 2007 RX-8 a couple weeks ago, man what a blast to drive

~Edit~ Deleted Wonky Picture~ added fresh one down the line.

Sorry,The picture got a little distorted while I was shrinking it to conserve bandwidth.

Edited July 7, 2007 by Ghadrack

[Vince]

I like the RX8, but I am kinda too old for that, and bmw insist on msrp. so i settle for this. Just hope all those kids around stop trying to race me in a little honda.

[Ghadrack]

Too old, what are you 80? Those Z's are beautiful cars, for the price and the feel though, the RX-8 was the only choice for me, I have never felt so connected to a car, after over a dozen other test drives, nothing felt as right.

I know the feeling wth regard to the kids, I can't pull up to a stoplight without having someone try to race with me. Oh well, that's the cost of having a stunning ride I guess

[areaseven]

Sweet cars you guys got there. And I see that you used Axelay's static cling Macross emblems on your suicide doors, Ghadrack.

[Ghadrack]

I still have the other decal in my F-150, I will probably pull it now since I am just using that as a work truck and put the second one back in my Macross display case.

Not to sound too much like a car saelsman, but Mazda is offering huge discounts on RX-8s right now, with the end of the model year (Which is comedy since the car essentially hasn't changed except for options since 2004) these cars are extremely affordable if you are in the market for a new ride. I gather from my research that the American audience is distructful of the rotary engine too, I have been told that the RX-8 while selling sufficiently to not warrant discontinuation, it hasn't been flying off the lots due to the "weird" engine and its "sports/sedan" status. I was actually out shopping for a Mazdaspeed 3, whihc are trememndously fun to drive, you can find very nice RX-8's for over 2 grand less, and while the Speed 3 had more off the line power, it was not nearly as fun to drive, and the speed 3 is fun to drive, the RX-8 just felt "right" to me though.

At any rate, I got mine for $21,500 before tax/tag/title and Mazda has dropped an additional $550 discount for the month of July, So I am pretty certain a shrewd bargainer could find an 06'or an 07' on a lot someplace and get them down to between $20 and $21K without too much of a struggle, the loaded GT's sticker over 30 and I have seen those discounted on the lots in the 27 range.

From a different angle.

[Golden Arms]

Nice Score Ghadrack. I had seriously considered getting a RX8 in 04, but I went a diff route. I've heard that the handling on those cars is very good.

[Vince]

I'm in my 30's, most of the RX-8 around here are driven by teenage boys and girls, but I do love those suicide doors, they were pretty much the only reason I considered RX-8. Besides, I was looking for a convertible. The choices were down to bmw and z, but I didn't want to pay close to 50k for a compact coupe, and the z price tag put it out of reach for most teenagers and is still not very high. Mine is a touring roadster, should have gone with the GT, but the biggest different is the bigger brakes in the gt I think. Handling is very tight, but not as tight as the RX-8. the engine sounds really good too.

[emajnthis]

what a coincidence; pfunk and i were actually having a discussion of the Z and the RX-8 at AP. I was a short signature away from purchasing an RX-8 about a year ago but decided it wasn't in my budget at the time. The RX-8's are great cars, and even greater when you turbocharge them; that's not by any means to be a childish "pimp my ride" statement, it's really due to assist in the inherent compression loss at low rpms with the Wankel Rotary (which is why they suck gas), which not only helps your HP but also will provide you better gas mileage. If you can, try to steal a turbocharger from a new RDX, it has a perfect turbo type that would be catered to both compression at low and high RPM providing better power and gas mileage. The only thing that Mazda should do to that motor to assist with its design is to incorporate a type of duel injection system. Have the injection on the first stroke, compression second stroke, and then on the third stroke have a high pressure injector and spark plug (similar to how a diesel is setup) which would allow for not only better ignition, but better fuel/air mixture and less fuel/air being used (especially if turbocharged since more air will be sucked in on the intake stroke). Not only would it assist in the fuel problem but then Mazda could (if they felt the need to) have a diesel version for the euro market. The use of the rotary in that car is also why it handles so well, the motor is basically three main parts, weighs nothing, and is incredibly small allowing for a well balanced vehicle (along w/good suspension components); i've seen photos of people who remove the radiator(s) and the air box and can literally stand in the engine bay (in fact i think seven has a photo of his RX-7 w/the motor out for reference).

[Vince]

Ghadrack, I'm really liking your ride.

[Ghadrack]

Thanks, trust me Vince, I dig yours as well. I wasn't putting down the Z, they are awesome cars.

For the time being, I am staying away from any serious modding of the car, this is my first "sports car" and it has plenty of pep for me as is. It' isn't the fastest car on the streets from the stoplight, but trust me, it goes when I want it to. There are plenty of lively discussion on the costs and benefits of turbocharging the rotary on the RX-7 and 8 forums, I have a lot of research to do before I even think about any upgrades like that, and I also have a long time under warranty that I don't want to void playing with aftermarket powertrain mods

[Lightning]

Lucky guys and your sports "coupes".

I scored a new Yaris hatch back in March. It's not bad so far, only complaints are that the engine is waaaay too quiet, there's no tach on the m/t hatch model, and that the stock shifter SUCKS. But other than that I'm happy with it.

so, has anybody else got any new rides lately?

[Vince]

I think any mod under the hood other than cold air intake and exhaust upgrade would void most new car warranty, not too sure about that, but I'm sure turbo and performance chips will. Some brands don't even allow cold air intake kit, unless you buy their upgrades.

I know the last model RX-7 was twin turbo, putting out 280+ ponies. it was supposed to be the same basic 1.3 L engine form the 80's. But I don't know what they did with the RX-8. I wasn't looking for a fast car, just a nice convertible. BTW, I hate speed bump now, high gas prices not helping either.

Lightning, my other car is a camry, smooth ride and very quiet. only down side is I keep sticking my key in the wrong car at work.

At least mine don't attract police like some red car does.