Is the Pontiac Solstice a V8 swap away from perfection?

John
By John Webber
Sep 9, 2022 | Pontiac, Opel GT, v8 swap, Solstice, Daewoo G2X, Saturn Sky, Pontiac Solstice | Posted in Features | From the May 2011 issue | Never miss an article

Photography by John Webber

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[Editor's Note: This article originally appeared in the May 2011 issue of Grassroots Motorsports.]

Not that he would, but if Bill Kroll chose to engage in certain illegal and antisocial stoplight behaviors, he could rule the streets.

In a typical zero-to-60 blast, his car would dust off a Dodge Challenger SRT8, a Shelby GT500KR, a Camaro SS, and a Jaguar XFR. In fact, it could light up pretty much everything out there slower than 4.4 seconds.

That is, of course, if Bill weren’t a law-abiding citizen.

Hypothetically, though, he could strike fear into the hearts of fellow drivers in his Pontiac Solstice. That’s because this stock-appearing roadster has undergone a full-monty conversion by Mallett Cars, which means it’s powered by a 6.0-liter Corvette engine that puts out 400 horsepower and 400 lb.-ft. of torque. Squint your eyes and this car seems to disappear in tire smoke. 

Summer Solstice

General Motors launched Pontiac’s Solstice in 2005 to great acclaim. Remember the advance-order hoopla spurred by “The Apprentice”? GM took orders for 1000 of the 2006-model-year cars in 41 minutes and put thousands more customers on a waiting list. Shortly thereafter, the Solstice was nominated for the North American Car of the Year Award and the Design of the Year Award. 

The automotive press seemed delighted with the Solstice, and GM was finally building a roadster that could compete with Mazda’s MX-5. With a base price of $20,000, sales ignited. Pontiac sold more than 21,000 examples in the car’s first year. 

The tiny Solstice featured a quirky new shape and promised open-air fun. GM’s 2.4-liter DOHC four-cylinder Ecotec engine provided 177 horsepower, which was routed through a five-speed manual or optional automatic transmission. 

The Solstice rode on GM’s Kappa platform, which it shared with the Saturn Sky, Opel GT and Daewoo G2X. The Pontiac roadster featured a 95.1-inch wheelbase but it weighed nearly 2900 pounds. With a zero-to-60 time of 7.2 seconds—and the ability to run the quarter mile in 15.8 seconds at 87 mph—it struck some testers as more cruiser than sports car. However, it handled and rode well enough for enthusiasts and got decent mileage to boot.

To keep costs down and reduce development time, Solstice engineers raided parts bins around the company. Cadillac’s CTS donated its rear axle, differential and automatic transmission. The steering column and other interior parts came from the Cobalt, and the back-up lights were borrowed from the Envoy. Engineers even put the touch on Hummer’s H3 for its five-speed manual transmission as well as its with heating, ventilation and air-conditioning modules. The Solstice shares a steering wheel with the Corvette and Malibu, among others. 

Somehow, all of these pieces worked well together. Solstice sales rose in 2007 as the car found a market niche with mostly young buyers. Answering demands for more punch, Pontiac introduced the GXP version, which was powered by a turbocharged 2.0-liter, 260-horsepower Ecotec engine. 

But as automakers have learned, timing is everything. As the nation’s economy tanked in 2008, so did Solstice sales. The introduction of a targa-top coupe in 2009 didn’t help matters. 

Winter Solstice

As every enthusiast knows, the last two years have not been good for the auto industry. Early in 2009, Uncle Sam and the taxpayers’ dime bailed out General Motors, which was reeling from plunging sales for all of its brands.

As the company teetered on the brink, it killed the 84-year-old Pontiac brand. Solstice production ended when the Wilmington, Delaware, assembly plant closed in July 2009. 

Pontiac built 65,724 Solstices over a four-year run. As the last of the Pontiacs, the car grabbed its place in automotive history. It was the final gasp of a once proud and exciting brand (well, if you ignore the Aztek).

Hit It With a Mallett

In the fall of 2005, Ohio-based Mallett Cars, a tuner shop known for building very quick Corvettes, decided to find out if a Chevy LS2 engine would fit in a Solstice. With a nip to the frame rail here and a tuck to the rack and pinion there—plus a dash of fabricated mounting hardware—the engine slipped right in. 

The Pontiac Solstice GXP was no slouch thanks to a turbocharged, 260-horsepower engine, but Mallett Cars wanted more. They shoehorned a Chevy LS2 V8 in the nose and ended up with lightning in a tiny two-seat bottle.

The shop selected a LuK Pro clutch to route power to the CTS rear end and the Solstice’s Aisin five-speed gearbox—those last two stock parts were deemed beefy enough to handle the torque. The exhaust system retained the OEM catalytic converters for 50-state emission compliance.

Next, Mallett installed a custom aluminum radiator, a special wiring harness, new plumbing and a reprogrammed engine computer. To beef up the suspension, they installed modified springs and shocks, added poly bushings, and made a few other suspension tweaks. Thus equipped, this potent Solstice weighed only about 200 pounds more than a stock example.

Let the fun begin! This prototype rocket worked so well that Mallett Cars declared they would build 1000 of them. Alas, they would not reach a quarter of that number. 

When 2.4 Liters Is Not Half Enough

Orlando-area car guy Bill Kroll bought his Solstice in late 2005. It’s an early-production 2006 model, No. 2970 in the original run of 10,000. 

While Bill bought it new, he’s technically the second owner of the loaded roadster. A friend had ordered the car but was no longer able to make the numbers work. When the dealer wanted to charge Bill $5000 over sticker to step into the transaction, his friend took delivery and the two made the deal on their own. 

Bill liked the little car well enough, but he’s a V8 guy at heart, having owned a number of Mopar muscle cars. So when he wanted to punch up the Solstice, he naturally started looking at a V8 conversion. He did a lot of research online and talked to a number of Mallett owners. Then he visited Mallett’s shop and talked to the principals. He liked what he saw.

In July 2008, he shipped the Solstice to Mallett’s shop. Six weeks later, they sent it back with twice as many cylinders, three times the rumble and quadruple the OMG factor. All of these extras didn’t come cheap, as the conversion tab was just over $26,000—the new LS2 ate up a good part of that tab.

Bill says he’s very pleased with the way the converted Solstice drives. “I love the power and the sound from the Corsa exhaust system,” he says. “The only thing I wish I’d done is change out the rear gears. The current gear is 3:91. You can get the limited-slip rear with 3:73 or 3:42 ratios, which would make it a little smoother in the lower gears.”

The V8 Mallett has an impressive power-to-weight ratio. In fact, if you give one a go at a stoplight, odds are good that you’ll end up reading the logo on the back of the car as it rockets away. 

With all of that power on tap, Bill wasn’t happy with the brakes. “They seemed a little soft to me,” he says. So he added more braking power with a kit from DDM Works, which included stainless lines, Hawk HPS pads, slotted rotors and high-temp fluid. He reports that the brakes now feel much more capable.

Only one problem has cropped up since: The engine harness wires were touching the exhaust manifold, which sent the engine into limp mode. A local Corvette shop, Corvette Masters in Maitland, Florida, solved the problem. 

Since the conversion maintains OEM parts, any shop can plug in the diagnostics for an LS2 Corvette and look for problems. And since the Mallett Solstice is basically a Corvette, there is plenty more performance on tap from any number of available LS2 mods.

Solstice Support

As it turns out, Pontiac and Solstice were not the only victims of the nation’s economic woes. Mallett Cars closed its doors without warning in mid-2009, leaving some owners scrambling to retrieve their vehicles. After a several-month shutdown, Mallett relocated to Concord, North Carolina, where the company is again providing tuner services as well as support for their conversions. 

Bill’s car is No. 18 of an estimated 200 Solstice conversions Mallett has completed to date. Online forums provide information and support for these enthusiastic owners, who realize their cars are now rarer than they ever expected. Examples show up for sale occasionally, generally with asking prices in the $40,000-to-$50,000 range. 

Bill thoroughly enjoys his stealthy Solstice and plans on keeping it. The peculiar reactions it provokes are part of its appeal, like the one Bill got when he pulled into a show for special-edition cars. The folks at registration, believing this was a mere regular Solstice, were going to deny him entry. After an exhaust sound check and a peek under the hood, however, they were delighted to let him in. 

And then there’s the possibility of that stoplight fun. Not that Bill would do that, of course.

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Comments
View comments on the GRM forums
wspohn
wspohn SuperDork
7/15/22 11:37 a.m.

No.

Nothing wrong with sticking a V8 into cars that didn't have them (some people seem to need loud noises to make them happy) but there is less reason to V8 a Solstice than many other cars as the stock turbo engine in the GXP has so much built-in tunability.

Stock = 260 bhp/260 Tq.

My GXP with a conservative tune and a slightly modified turbo (larger impeller) = 375/375...and still gets great mileage when you aren't at full throttle.

There are a lot of owners that have swapped out to a larger turbo and are putting out 4-500 bhp.

Want a bunch more?  See this (same engine as in the Solstice):

715 whp

https://www.youtube.com/watch?v=2S6XiC0ZDgE

PS - my mildly tuned Solstice gets into the 12s in the 1/4 mile but returns c. high 20s mpg when not under boost

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
7/15/22 12:15 p.m.

It's not all about peak :) Here's a 2.0 turbo vs an LS3.

M2Pilot
M2Pilot Dork
7/15/22 12:17 p.m.

I've never driven nor even rode in one of these cars. I like them.  But, it seems that I've seen many mentions of awful ergonnomics.

Defined motorsports
Defined motorsports SuperDork
7/15/22 12:37 p.m.

Our club has a dude running an ls6 in his for CAM. That thing is crazy. 

Puddy46
Puddy46 New Reader
7/15/22 12:47 p.m.
M2Pilot said:

I've never driven nor even rode in one of these cars. I like them.  But, it seems that I've seen many mentions of awful ergonnomics.

Fully agree.  If a V8 swap helps being able to put more than a pack of socks in the trunk with the top down, that's where you'll get the most improvement. 

racerfink
racerfink UberDork
7/15/22 12:49 p.m.

I could see how the LFX might be a fun swap for the Solstice/Sky twins.

wspohn
wspohn SuperDork
7/15/22 1:03 p.m.
Puddy46 said:
M2Pilot said:

I've never driven nor even rode in one of these cars. I like them.  But, it seems that I've seen many mentions of awful ergonnomics.

Fully agree.  If a V8 swap helps being able to put more than a pack of socks in the trunk with the top down, that's where you'll get the most improvement. 

No problem in my car - I can get 3-4 cases of wine in the back.... devil

Puddy46
Puddy46 New Reader
7/15/22 1:19 p.m.
wspohn said:
Puddy46 said:
M2Pilot said:

I've never driven nor even rode in one of these cars. I like them.  But, it seems that I've seen many mentions of awful ergonnomics.

Fully agree.  If a V8 swap helps being able to put more than a pack of socks in the trunk with the top down, that's where you'll get the most improvement. 

No problem in my car - I can get 3-4 cases of wine in the back.... devil

Fair play on that one!  Although the targa is kind of cheating since the issue is the soft top takes all the room in the trunk, if I remember correctly.  

NickD
NickD MegaDork
7/15/22 1:20 p.m.

While I'm not a huge fan of the drivetrain, the majority of my gripes with the Solstice come from it's bulbous styling, low-rent interior, and garbage ergonomics, and a V8 doesn't fix any of that..

fatallightning
fatallightning Reader
7/15/22 1:48 p.m.

In reply to Puddy46 :

It's actually the gas tank that protrudes in there heavily. The soft top then sits on top of that and takes the little side indentations you had, leaving a soft duffel sized sliver along the rearmost section of the trunk. 

2007GXPZOK
2007GXPZOK
7/15/22 2:39 p.m.

My Solstice was fun with the turbo motor but the DI was a no go for my tuner. I may be one of the only dry sump LS3's on the track and the car seriously runs the way GM should have built it form the factory. No turbo hit at the apex of corners allows me to make a lot of the German girls cry along with some Corvettes, Camaros and Mustangs. I've been told it's frustratingly fast. Mind you mine is a fully sorted race car with full stand alone Link ECU with traction control, MK60 anti-lock brake system and Brembo GT Corvette big brake kit. 

te72
te72 HalfDork
7/16/22 1:55 a.m.

In reply to 2007GXPZOK :

That track reminds me a bit of Wild Horse Pass, but I haven't seen it in about 15 years...

 

As for the Solstice, it was probably the first new car I was excited about the possibility of affording. Numbers wouldn't have worked out for me back then. Got into NB Miatas instead, no regrets. Same concept of a V8 roadster, but what, 600 lbs lighter than a V8 Solstice? Why are they so heavy?

jfryjfry
jfryjfry SuperDork
7/16/22 8:25 a.m.

In reply to 2007GXPZOK :

Would love to see a build thread on your car - it sounds awesome

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
7/16/22 9:46 a.m.
NickD said:

While I'm not a huge fan of the drivetrain, the majority of my gripes with the Solstice come from it's bulbous styling, low-rent interior, and garbage ergonomics, and a V8 doesn't fix any of that..

You are also describing most F-bodies and Corvettes, too.

wspohn
wspohn SuperDork
7/16/22 11:47 a.m.

Styling is personal preference. I never thought much of the convertibles but for some reason the coupe shape hit my buttons - go figure.  Glad it did with only a few months on the market and 1270 odd made.

The ergonomics aren't that bad to live with  - you forget about things like crappy breakable drink holders and leaving dents on the doors if you slam the hood down when the doors are open, and complaints about interior comfort are common among new owners.  I have always found that when you test drive a strange car you are never sitting in it the way you will if you own it.  You relax and slump down when you are used to it and can often find a best driving position (for me, with seat a couple of notches forward from the rearmost limit and the back raked right up against the rear bulkhead.

It is funny, my other modern sports car, a BMW Z4M coupe, has one of the most comfortable seats I have experienced yet I see other owners complaining about them. I keep wanting to ask what the heck they are doing, but I'm too polite to ask if their name is Quasimodo.

And while I appreciate Keith's correct observations on the differences between a turbo 4 and an NA V8,  in driving the progression with the Solstice is very smooth and of you are cruising at 2500 or so and floor it, the power comes in quickly and smoothly.  IMHO too many owners make poor decisions on mods - they opt for over large turbos that exhibit excessive lag because the peak power numbers look nice to them. The stock turbo has virtually no lag and my upgraded version that pushes more air doesn't have much appreciable lag either, but going beyond that point definitely affects day to day drivability.

 

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
7/16/22 12:56 p.m.

It is a shame the coupe wasn't higher production. Much better looking to me. 

kevlarcorolla
kevlarcorolla Dork
7/16/22 1:19 p.m.

In reply to NickD :

The Saturn version solves the bulbous styling nicely :)

dean1484
dean1484 GRM+ Memberand MegaDork
7/16/22 2:02 p.m.
wspohn said:
Puddy46 said:
M2Pilot said:

I've never driven nor even rode in one of these cars. I like them.  But, it seems that I've seen many mentions of awful ergonnomics.

Fully agree.  If a V8 swap helps being able to put more than a pack of socks in the trunk with the top down, that's where you'll get the most improvement. 

No problem in my car - I can get 3-4 cases of wine in the back.... devil

I was never a fan of the looks of convertible version of these cars but DAM does that look good. 

SkinnyG (Forum Supporter)
SkinnyG (Forum Supporter) PowerDork
7/16/22 4:06 p.m.

I like them.  It's almost a modern reboot of the Cheetah to me.

Peabody
Peabody MegaDork
7/16/22 4:33 p.m.

I like the style, it's a good looking car. But I hated the one I drove. It felt more like a tractor, than a sports car, and I hated the seating position. It could have been the one I drove, though, it was a E36 M3box

GPz11 (Forum Supporter)
GPz11 (Forum Supporter) HalfDork
7/18/22 10:23 p.m.

So can big boys fit in a Solstice? I'm 6'3" 275lbs and once our BMW bike sells, a Solstice is on the short list.

NickD
NickD MegaDork
7/19/22 6:14 a.m.
GPz11 (Forum Supporter) said:

So can big boys fit in a Solstice? I'm 6'3" 275lbs and once our BMW bike sells, a Solstice is on the short list.

Not comfortably. I'm 6'3", 240lbs and they are not a comfortable fit. Driving the stick shift ones is really uncomfortable because even with the seat back, my kneecaps are against the dashboard. My NA Miata has more interior room.

GPz11 (Forum Supporter)
GPz11 (Forum Supporter) HalfDork
7/19/22 8:04 a.m.

Well shoot, that sucks. The Missus even likes them too.

Yeah, if they are smaller than a NA Miata, I've got no chance of fitting. 

fatallightning
fatallightning Reader
7/19/22 8:36 a.m.
GPz11 (Forum Supporter) said:

So can big boys fit in a Solstice? I'm 6'3" 275lbs and once our BMW bike sells, a Solstice is on the short list.

I'm 6'0 255lbs, 33" inseam and fit. Seat as low as she'll go, and all the way back. The clutch pedal is almosttt too far like this, so there's a shot. I had an NA Miata, and I remember the cabin being snugger in that, been a few years though. I'll see if I can take a reference photo.

wspohn
wspohn SuperDork
7/19/22 10:44 a.m.

One bit of trivia on the Solstice coupe - it would have been a true fixed head coupe, except that the safety approval process would have had to be redone at considerable cost, so GM opted to use a removable top panel, which sidestepped that expense. 

Unfortunately they bodged the design of the top by not making the panel that you remove storable behind the seats so they offered a collapsible soft top that would stow there, but not well. Today the soft top changes hands for around $2K as not many were made (I bought my coupe new off the lot but didn't want a soft top - I'd have preferred the hard top to be welded to the body!

Changing the top (an amusing video):

https://www.youtube.com/watch?v=U60VlW8ucCM

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