When did Pontiac make a V8 Bonneville?

[Yooformula]

Greenfield Pontiac has a GXP on their lot that looks sweet! Norstar V8..... :shades

[T-Bag]

Old bonnies were always v8's back in the 80's. The GXP has been advertised for a few years now and FINALLY released.

[Daytonapacecar959]

Greenfield Pontiac has a GXP on their lot that looks sweet! Norstar V8..... :shades
At Foster we have one on the lot also.

[Cryptic]

my 65 Bonnville has a 389 V8 :sucks

[Yooformula]

I meant recently wiseasse!! Used to be 3600 V6s or the blowers but I didnt know they were making V8s recently.

[A B4C Z]

They have been on the lots since at least febuary. Wonder how they move on the street. It a lot of car to begin with.

Kyle

[SSmike1]

I meant recently wiseasse!! Used to be 3600 V6s or the blowers but I didnt know they were making V8s recently.

yes they have been V6 3800Liter motors, ever since the bonniville was switched to a front wheel drive.


NEW for 2004, the Top of the Line Bonneville, the GXP,
has a Caddilac Northstar V8 transverse motor.

It came out for 2004, in feb/march time frame.

I know, i was shopping for one at the time,
and test drove them,
and Greenfield pontiac had an 2003 SSEI on the lot,
brand new, that they Gave me such a good price on
that i could not pass it up.

But Yoosof is correct, all the FWD Bonnevilles are the 3800 V6 motor,
otherwise.

:rolleyes:

[GHOSST]

That 3.8 litre is one hot engine. Its in all the FWD Bonneville's 1988-2005(with the exception of the 4.6 northstar in 2005). GM puts the 3800 in most of thier popular models, improving it every other year since 88(early models were sh!t). Most of the hot models have the exception of the luxury/performance 3800 supercharged, SSEi, GTP, Buick P/A Ultra, Buick Riviera, Impala SS, Monte Carlo SS, hec, the retro V8 idea is awesome, but does it deliver as well as puttin the s/c on a 3800 V6 FWD???

[Yooformula]

i jsut never knew that they made newer models with a V8 anymore. Thanks for the news though.

[Anakonda69]

every new bonneville with a v-8 model gxp i have seen has the 4.8 in it....maybe the ssei u can get with a 4.6 now......my mom has a 97 se fully loaded 3.8 v-6 and it hauls a$$.....pretty fast and for front wheel drive it pulls very good and spins the tires with ease....

[Syclone0044]

Looks like the Pontiac Bonneville GXP comes standard with the 4.6L V8. It has:

275 HP @ 5600 RPM
300 TQ @ 4000 RPM
10.0:1 Compression
3.66 x 3.31 Bore/Stroke
32 Valve, DOHC.
Source: MSN CarPoint http://autos.msn.com/research/vip/spec_engines.aspx?modelid=11202&trimid=-1&src=VIP&tab=2&sub=1

This compares pretty well to the Ford 4.6L DOHC V8 from the Cobra motors:
305 HP @ 5800 RPM
320 HP @ 4200 RPM
10.1:1 Compression
3.55 x 3.54 Bore/Stroke
32 Valve, DOHC
Source: MSN CarPoint http://autos.msn.com/research/vip/spec_engines.aspx?modelid=10826&trimid=-1&src=VIP&tab=2&sub=1

My guess is the Ford 4.6L V8 has a bit more cam, noticing the higher RPM HP Peak and TQ Peak, and respective HP/TQ increases. The Ford 4.6L V8 also has a perfectly square Bore/Stroke, something I've never noticed before. You'd think it would make more power based on that, or else the "Square Bore/Stroke Theory" really doesnt amount to much HP gain. The Pontiac has a 3.66 x 3.31 bore/stroke. (Standard SBC has 4.00 x 3.48, the LS1 is a lot closer together.)

Unfortunately I'm sure GM will never put this V8 in any serious drag racing contendors, being that it's a FWD engine platform. I wonder what transmission they are putting behind it anyways (4T80E-HD?), and what kind of reliability it has.

[Prince Valiant]

You'd think it would make more power based on that, or else the "Square Bore/Stroke Theory" really doesnt amount to much HP gain. The northstar can be found on the XLR caddy...basically a C6 chasis with the north sout arrangement of the northstar v8 at 320 or 340hp I think?

And fwiw's, a "square" arrangement is not the best way to make power.

Why? Several factors are involved:

1. Bore size helps air flow into the cylinders. This is accomplished a couple of ways. a) Bigger bore allows for larger valves in a given cylinder...larger valves and ports will equal better airflow, important at higher rpm's. b) Small bores are more likely to run across valve shrouding. As the valve opens from the heads, it'll move closer to the edge of the cylinders. At the edges where the valve approaches the cylinders, an area of high pressure develops as air won't flow easily to the cylinder walls (naturaully) and thus again, less air flow.

The deacrease air flow potential of a smaller bore won't affect it at a given lower rpm...so torque production wouldn't be affected. However, since power is a function of rpm, horsepower would be limited by the above factors...as we know a given displacements air consumption increases on a minute by minute basis with rpm's. If your cylinder heads can't support the flow, you can't make the power.

2. Longer strokes equal greater piston speeds. This is a concern because again a couple of factors. a) There are ultimate limits to safe piston speeds. A general rule of thumb is 4000ft/sec maximum piston speeds...this is of course a generalization, but a fair one none-the-less. There are some production engines that exceed this rate, nor is it hard to build a motor that can exceed this...but it does serve that piston speeds IS in fact a concern that needs to be considered and for a longer stroke will always have higher piston speeds at a given rpm. b) Piston speeds effect on air flow. The faster a piston travels, the stronger effect it has on the intial airflow into a cylinder...so a longer stroke will generally have better torque charactersitics at low rpms because the greater piston speeds will enhance the low rpm air flow at the given lower rpm, and low rpm air flow/velocity is critical for good low rpm torque production...however, a point is reached in which piston speeds become too great, and the greater piston speeds will cause a turbulence effect at higher rpms, and of course torque production will suffer, leading to decreased power.

c'tnd

[Prince Valiant]

other things play a role as well, in that it's harder to have a good rod/stroke ratio as your stroke increases...and that affects upper rpm breathing, dynamic cylinder pressures during the combustion events, piston acceleration and deceleration, and cylinder sidewall thrust and frictional loses...all negatively I might add.

For further evidence of the oversquare vs square or undersquare motors, refer to some of the greatest small block racing motors ever. Chevy 302? 4x3. Ford 302 4x3. Chrysler 301? 4.04x2.94. Now, these motors are revvers....you need to spin them up to make power, and is why most aren't revered as much on the street (you couldn't find the chysler 301 on the street btw...only as the 340v8...and ford guys, I am refering to the boss 302 of old, ford did a good job on the windsor based 302 to enhance streetability in the fox-bod mustangs). But when limited by displacement as the trans am racers were, to make the most power with no comprimise, they skewed to the oversquare.

[Syclone0044]

Why do you suppose GM created the LS1 with a reduced bore and increased stroke if the old 4.00 x 3.48 were desirable? I also attribute some of the LS1's performance to this factor. (The great cylinder head design is #1 though)

[Rocket Power]

That 3.8 litre is one hot engine. Its in all the FWD Bonneville's 1988-2005(with the exception of the 4.6 northstar in 2005). GM puts the 3800 in most of thier popular models, improving it every other year since 88(early models were sh!t). Most of the hot models have the exception of the luxury/performance 3800 supercharged, SSEi, GTP, Buick P/A Ultra, Buick Riviera, Impala SS, Monte Carlo SS, hec, the retro V8 idea is awesome, but does it deliver as well as puttin the s/c on a 3800 V6 FWD???
and the Olds LSS ( had to throw that in there. :goof )

[Prince Valiant]

Why do you suppose GM created the LS1 with a reduced bore and increased stroke if the old 4.00 x 3.48 were desirable? I also attribute some of the LS1's performance to this factor. (The great cylinder head design is #1 though)Sorry, but I would disagree. Correlation does not equal causation in this case.

The primary reason to design the smaller bore to reduce the combustion area and improve the quench for better control of emissions. In conjunction with increasing the stroke, this also helps to raise the engines tolerance to compression and yeilds a greater effeciency. While the LS1 give up to the SBC/lt-1 guys the better bore/stroke ratio...the LS1 outshines the LT1 with yes...better heads (which I agree...most the power increase comes from in this particular case) with superior valve angles, but also better intake, better exhaust manifolds, probably more agressive cam timing (evidenced by it's higher torque peaks of 2400rpm vs 4000rpm...of course, this isn't solely cam timing as again, the 235cfm flow heads of the LS1 vs 215cfm heads of the LT-1 also helps determine where the car makes it's torque, intake manifold as well) better rod/stroke ratio of the LS1 (also may move the power peak up a few rpm's as well). So the LS1 improves on many different areas while gives up but 1 in my opinion.

If the reason was solely looking for performance, then why does the LS2 go back to a 4 inch bore? Why not a just combine the 3.90 inch bore and go with a 3.83 inch stroke to yeild the same 6 liter (364ci) displacement? Either by increasing the displacement via bore increase, or via stroke increase you only have to use new pistons (that is unless the stroke increase is so large as to necessitate clearencing or additional machining of the block...not the case here though) It is essentially just a performance engine...why compromise for less performance?

Look at many indy car motors...they'll range from 1.25 bore/stroke ratio to as high as 1.5 :wow Hey, why haven't these guys learned anything from the ford modular motor development team?

Now, don't get me wrong...I've said it to you before that there are situations where a square or undersquare motor shines, and under boost is certianly one of them. But for NA motors where they have to draw air into a given displacement via vacumn, oversquare will always allow for the greatest advantages when producing power

[Syclone0044]

LT1 torque peaks of 2400 RPM! :wow Talk about a Super-Torquer :-)

[Brian98GTP]

I like the styling of the GXP Bonnie... People I know that own the Bonnie GXP say its one of the best car Pontiac has made, as far as quality/comfort....But for a price of close to 40 G's, you'd hope it'd be damn nice!!



I also like the way the 2005 Grand Prix GXP is going to look..... Looks like it will have a 5.3 liter V8 stuffed into it, sporting 18" rims Yo!


http://www.kanco.com/gp/images/gpgxp.jpg

All Pontiac vehicles will have the GXP badge... (except the Aztek, Thank God)


Here's a cool advertisment showing the GTP w/Comp G, Bonnie GXP, and GTO....
It 'Sorta' relates to the topic... :-P


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[GHOSST]

and the Olds LSS ( had to throw that in there. :goof )

I was hoping someone had some more:thumbsup, those are only the ones I know, and most people didn't even know they supercharged a Park Avenue:goof, or a Riviera. GM just full of suprises:rockwoot:

[Prince Valiant]

LT1 torque peaks of 2400 RPM! :wow Talk about a Super-Torquer :-)
i was suprised seeing that as well...if I had relied on an approximation of what I thought, I would have guessed around 3200-3400rpm.

[MilTownSHO]

Yep its the SSEi replacement!