APS boosts Pontiac G8 GT to 557 bhp

[hks786]

APS, the specialist tuning house with over 25 years of turbo tuning, has turned a Pontiac G8 into something of a Pontiac GR8 (or great). Realizing some potential in the 6.0-litre V8 used in the G8, APS then got to grips with it by installing an intercooled twin turbo system, which is cleverly mounted under the chassis so heat moves away from the engine. Clever yes, if you live in a town with no speed humps and other road oddities.

What power then? How’s about 557 bhp on the trot? And torque? That’s 583.8 ftlb. It’s good figures by any measure, and APS says its system ensures access to all this munchy power and delivers through quite a flat range. The intercoolers work hard to cool things down such that APS claims a quarter mile run twice or more up and down the straight will not even sweat its G8 system.

So those who own VXR8s and HSV Clubsport R8s will be welcome at APS to see how much further things can go. APS themselves reckon there’s quite a few more horses stored under the ‘hood here and perhaps in time it may all come home to roost.

[hks786]

[Year's_End]

Beastly.

Btw, the VXR8 looks so much better than the G8 imo.

[Boostedg35]

OMG 40k and you have a m5 killer insane

[phrozen06]

You knew this was coming.

[FinInk]

wow nice looking car I wouldnt mind owning one at all. Im even impressed with the older GTO's when ever one drives past me.

[AJerman]

They added twin turbos an only hit 557?

[flyinb501]

That's awseome! My buddy had a Z28 with a turbo mounted in the rear like that, and the thing was insane! Sounded just mean as hell!

[ChaneRZ]

damn! everyone is making twin turbo now!

[Digital.James]

Holdens (which the G8 is, as well as the GTO previously) have been being turbo charged for a long time in Australia. Some guy I knew had a bolt on turbo kit for the GTO that made 525whp right out the box.

[TSM330i]

Originally Posted by AJerman

They added twin turbos an only hit 557?

The engine wasn't designed to have boost from the factory, so the boost is probably about 6psi.

Callaway has a supercharger for the LS3 engine that puts out 580hp at only 7psi.

You say "only 557." That's a lot of horsepower.

[just4kickz]

Originally Posted by Bimmer Loyalist

Beastly.

Btw, the VXR8 looks so much better than the G8 imo.

word

[AJerman]

Originally Posted by AW325xi

The engine wasn't designed to have boost from the factory, so the boost is probably about 6psi.

Callaway has a supercharger for the LS3 engine that puts out 580hp at only 7psi.

You say "only 557." That's a lot of horsepower.

Sorry, I'm coming from the high performance world. 557 isn't a whole lot to me. I'm not saying it's not a lot of horsepower, but not to me. People frequently put turbos on their Cobras and hit 700+ RWHP depending on their engine setup.

But now that I think more into it, it's not a forged bottom end, so you're right, it's not designed for that much power. Still, I'm not particularly impressed. Lets see someone forge the bottom end and crank up some boost. 557 out of a 6.0 is nothing. For the cost of the turbo build they might as well do the engine as well and get some real numbers.

[ToothDoc]

It's probably closer to 600 rwp. Dyno dynammics dynos really give low numbers. If I recall, a dyno dynamics gave me 239 on my IS350 but a dynojet gave me 259.

[SLV335I]

Originally Posted by AJerman

Sorry, I'm coming from the high performance world. 557 isn't a whole lot to me. I'm not saying it's not a lot of horsepower, but not to me. People frequently put turbos on their Cobras and hit 700+ RWHP depending on their engine setup.

But now that I think more into it, it's not a forged bottom end, so you're right, it's not designed for that much power. Still, I'm not particularly impressed. Lets see someone forge the bottom end and crank up some boost. 557 out of a 6.0 is nothing. For the cost of the turbo build they might as well do the engine as well and get some real numbers.

That's a lot of power for a bone stock car with just a twin turbo kit installed at only 6-7.5lb of boost. They can make more but this is a kit that you just install and drive. You have to think that APS also wants this kit to be reliable. As for the Cobras that have over 700+ RWHP they were FI from the factory so it’s also not impressive. Not everyone wants a car that to get traction under 100mph you need to mount drag radials or slicks.

[AJerman]

Originally Posted by SLV335I

That's a lot of power for a bone stock car with just a twin turbo kit installed at only 6-7.5lb of boost. They can make more but this is a kit that you just install and drive. You have to think that APS also wants this kit to be reliable. As for the Cobras that have over 700+ RWHP they were FI from the factory so it’s also not impressive. Not everyone wants a car that to get traction under 100mph you need to mount drag radials or slicks.

You make it sound like it's a $50 job. My point is that most turbo installs cost upwards of $10,000. If you going to do that much work, what's another few thousand to actually make them make real power?

I also never said 700+ was impressive for a Cobra. That's pretty much a base mildly tuned TT install. Considering they are 4.6L engines and only make 390 BHP from the factory, that's quite a jump still.

[SLV335I]

Originally Posted by AJerman

You make it sound like it's a $50 job. My point is that most turbo installs cost upwards of $10,000. If you going to do that much work, what's another few thousand to actually make them make real power?

I also never said 700+ was impressive for a Cobra. That's pretty much a base mildly tuned TT install. Considering they are 4.6L engines and only make 390 BHP from the factory, that's quite a jump still.

If you don’t call 557 RWHP "Real Power" then you are going to be really disappointed with your 335i. Also a TT kit and fuel system for a Cobra would cost also around 10k installed and tuned. The single turbo kits are $5-6K for the kit alone. The G8 make about 310 RWHP stock and with just 7lb of boost it makes over 550 RWHP. I call that great.

[AJerman]

Originally Posted by SLV335I

If you don’t call 557 RWHP "Real Power" then you are going to be really disappointed with your 335i. Also a TT kit and fuel system for a Cobra would cost also around 10k installed and tuned. The single turbo kits are $5-6K for the kit alone. The G8 make about 310 RWHP stock and with just 7lb of boost it makes over 550 RWHP. I call that great.

My 335 isn't supposed to be a race car. I didn't buy it with that intention, so I won't be disappointed. Not to mention that I've been driving my 97 Mustang GT for the last month while waiting for my Cobra, so that will make my 335 feel like a rocket ship.

I'm not sure what you meant by a TT setup would cost around 10k for a Cobra also, that's what I was just saying.

Either way, you're missing my point. If you're going to drop something like $10k on turbos, to me it would make sense to forge the engine for another couple thousand and really get power out of it. Doing a $10k turbo job that is only going to live up to it's full potential seems silly to me.

The G8 GT actually has 360 HP stock, not 310, but that's still somewhat disappointing. The 03-04 Cobra had 390 because it was supercharged. Previous models made 320 HP with a 4.6 L engine. 360 seems very conservative on a 6.0L engine, not to mention the car is huge so that's going to feel like a whole lot less.

Don't get me wrong. I like the concept of the G8. In fact, I love it. However, I think this first model isn't quite where it needs to be to live up to it's name. They should have come out from the start with the GXP model.

Then again, it's an LS engine. Slap some heads and a cam on there and it'll start cranking out the HP. I want to see someone with a G8 with heads, cam, forged internals, and a TT kit. THEN we'll start seeing something really impressive.

Like I said, you're missing my point. I'm not saying 557 is bad, it's just not that impressive to me yet. Anyone can slap turbos on a car and gain a bunch of HP, but I want to see them do it right and see some big power out of it.

[SLV335I]

Originally Posted by AJerman

My 335 isn't supposed to be a race car. I didn't buy it with that intention, so I won't be disappointed. Not to mention that I've been driving my 97 Mustang GT for the last month while waiting for my Cobra, so that will make my 335 feel like a rocket ship.

I'm not sure what you meant by a TT setup would cost around 10k for a Cobra also, that's what I was just saying.

Either way, you're missing my point. If you're going to drop something like $10k on turbos, to me it would make sense to forge the engine for another couple thousand and really get power out of it. Doing a $10k turbo job that is only going to live up to it's full potential seems silly to me.

The G8 GT actually has 360 HP stock, not 310, but that's still somewhat disappointing. The 03-04 Cobra had 390 because it was supercharged. Previous models made 320 HP with a 4.6 L engine. 360 seems very conservative on a 6.0L engine, not to mention the car is huge so that's going to feel like a whole lot less.

Don't get me wrong. I like the concept of the G8. In fact, I love it. However, I think this first model isn't quite where it needs to be to live up to it's name. They should have come out from the start with the GXP model.

Then again, it's an LS engine. Slap some heads and a cam on there and it'll start cranking out the HP. I want to see someone with a G8 with heads, cam, forged internals, and a TT kit. THEN we'll start seeing something really impressive.

Like I said, you're missing my point. I'm not saying 557 is bad, it's just not that impressive to me yet. Anyone can slap turbos on a car and gain a bunch of HP, but I want to see them do it right and see some big power out of it.

310Hp was to the wheels. Also I see what you’re trying to say. But APS is known for making great power with a bolt on kit. Not everyone has an extra 4-5K for an engine build. And most people would be happy with almost 600 RWHP from a car with a bolt on turbo kit. I’m sure that G8 would give a 700 RWHP cobra a run for its money. I have seen many mustangs at the track and also many street races over the past 10 years and mustangs no matter what was done to them never been that fast. I’m not trying to make you mad about ford vs.? I’m just saying that most mustangs I have seen in Chicago no matter what has been done to them have been beat by something that had less power. They have never impressed me. Even the Ford GT. I would take a new ZR1. That would wipe the floor with it.

[AJerman]

Originally Posted by SLV335I

310Hp was to the wheels. Also I see what you’re trying to say. But APS is known for making great power with a bolt on kit. Not everyone has an extra 4-5K for an engine build. And most people would be happy with almost 600 RWHP from a car with a bolt on turbo kit. I’m sure that G8 would give a 700 RWHP cobra a run for its money. I have seen many mustangs at the track and also many street races over the past 10 years and mustangs no matter what was done to them never been that fast. I’m not trying to make you mad about ford vs.? I’m just saying that most mustangs I have seen in Chicago no matter what has been done to them have been beat by something that had less power. They have never impressed me. Even the Ford GT. I would take a new ZR1. That would wipe the floor with it.

Yeah, at high speeds, because they are bricks. I've never seen them have any problem keeping up with anything at the same power and weight level under 100 MPH though.

But I assure you that the G8 wouldn't even come close to a 700 RWHP Mustang. You're forgetting that the G8 is a big 4000 pound sedan. But then, that's the appeal in the G8, it's a fast sedan for dad. Who it is faster or slower than is irrelevant.

[Doc GTO]

Originally Posted by AJerman

They added twin turbos an only hit 557?

At 7lbs of boost . . . Trust me when I say that 800 on this setup is not a problem.

We have GTOs with this same setup using a methonol system and making 650 on the stock blocks and with built bottom ends, making 800+ with no issues and getting 25+ on the highway.

How's that

[Doc GTO]

Originally Posted by just4kickz

word

It is a front bumper swap and different wheels. Did it to my GTO. Not hard at all.