Saturn Sky Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
57 Posts
Discussion Starter #1
This is a long post but I'm interested in comments and suggestions, whether you agree with me or not. . . .

As a 40+ year domestic car and hot rodding nut I was excited about the Solstice and Sky from the moment I first heard of them. I’ve hung around this and the Solstice forum for some weeks now absorbing info and I wanted to post what I have decided to do for my “ultimate performance” Solstice, a project I will start later this year (I plan to buy one of those Solstices people will be dumping to upgrade to the GXP come start of next winter, or a bargain basement SKY (they seem prettier to me).
Below, I’ll explain (1) why I’m not going with an LSx engine even though I own five and know them inside out, (2) why a built Ecotek with a SC is tempting , but . . and (3) the route I’m going to take using an aftermarket derivative of the GM “109” block.
MY GOAL IS TO KEEP WEIGHT LOW, AND TO PRESERVE THE SUBERP BALANCE, HANDLING, AND LIGHT FEEL OF THE CAR, AND NOT GO PAST THE AMOUNT OF POWER THE CHASSIS CAN HANDLE, WHICH I FIGURE IS ABOUT 350 RW.

1) No LSx. I apologize to anyone who thinks I’m calling their LSx Solstice or Sky ugly. I'm not, it’s a neat idea, but I'm not sold. My decision is no doubt in part because I’ve done the “big modern V8” thing, and because by my calculation an LSx Solstice will weigh a bit more than a stock C5 ZO6 (which weighed somewhere between 3085 and 3125 lbs depending on the source you look at). Been there, done that.
But I also suspect the LSx-Solstice will turn out to be like all those Ford small block V8 Miatas: a good idea but not necessarily a good car. I really started out wanting to do an LS6 conversion (I have a spare sitting in the garage). But when I do the math, carefully as I can, I keep getting the car weighing more than and also more nose heavy than the C&D article indicated (did those stats include the AC?). And I think eventually one will want the heavier M6 transmission for durability with 400 ft lbs of torque. By the way one thing any LSx Kappa owner ought to do is move the battery to the trunk: that shifts a whole 1% of the car’s weight from the front to the rear.
Another things, its just about impossible to get good headers onto an LSx in a Kappa, and in forty years of hot rodding that has taught me that is a reliable sign that an engine really won't fit well in the car. I think the drive-train (at least the rear end) willtake the power, but it’s marginal: and I’ve seen Magnusen SC’d LS6s rip apart stock ‘vette rear ends (that's why they make girdles and hardened shafts for the vette), so I think people talking about superchargers and the LS7 will end up with badly broken cars.
But the deal maker for me is the issue of using and controlling the power: the Kappa's wheelbase is 9.5 inches less than a ‘vette’s, the track right at 2” less, the biggest tire you can under the fenders just the size of a stock vette’s, and there is about 100+ lbs less weight on the rear axle: not a good formula for putting power and control to the ground. Can a good driver keep it on the road? Of course, the original Ford Cobra had the same wheelbase and weight and power to weight ratio (although more weight on the rear end). But it's worth noting that GM has never installed an LSx in a production two-seater without traction and stability control standard: even with the 'vette's advantages, that power is hartd to control. Mine has saved my butt three times (yeah I know, I have a lot more power now, but I drive like the old man I am). It’s not going to be a deathtrap, but I don’t expect it to be a car that can gracefully handle the power.

2) Its very tempting to put a turbo or SC on the stock 2.4 Ecotek. I think the result will be spectacular. A built engine with good aftermarket crank, rods and pistons (Crower, CP, etc.) would be bulletproof at 350-375 HP flywheel. Maybe 15 lbs of boost and you’re there: you might have to O-ring the heads to make it durable, but even so its not that extreme. But I’m not a fan of fours, and I figure plenty of people will do that.

3) So I'm going to do the GM 3.8 liter 90 degree V6 – the engine that’s done duty in many Granny grocery getters over the years, but when fitted with turbos enabled the Buick Grand National (3400+ lbs) do the 13.1 in the quarter, stock.
This engine is proven to do over 850 RWHP on the on pump gas with modified turbos and a built bottom end, etc., but I won’t even go for half of that. I’ll use an aftermarket aluminum block (e.g., TA Perf.) and a light duty (and light) Crower stroker crank for a full 4 liters, and the lowest, lightest, small-valve heads (shaved TA Intimidators), with stock rockers (lightweight and they allow compact rocker covers). It will be only 2/3 of the displacement of an LS2, but the long-block will weigh about 100 lbs less. I’ll save more eight later because there are only ¾ as much manifolds, fuel rail, injectors, pans, etc.
GM’s “109 block” is basically the back ¾ of an early 80s 5-liter V8, so there is not only a lot less of it than with a V8, but its center of gravity will be 2 ¼ - 2 1/2 inches farther back in the chassis than an LSx, for better balance. In fact it will beo over an inch farther back than the stock engine -- its 3+ inches SHORTER than an Ecotek 2.4 But in addition, the alternator, AC, etc., on the front on the engine will be a whopping 5 inches farther back in the car – its that much shorter overall compared to the LS1. There’ll be a big empty space in front of the engine, which can be used to cluster accessories – minimizing bracket weights, etc., and headers will fit , coming straight forward, to a single small (again, light) turbo: only about 8 lbs of boost.
I will get 335 RWHP and 325+ ft lbs at the rear wheels from 2000 RPM to 5800 RPM, (if I don’t I’ll change the cam, increase the boost, this isn’t even trying for this engine), and use a single exhaust and cat (again, lighter). The car will have the same power to weight ratio as an LS2 Solstice, but weigh right at 2950 lbs or less with AC. A good deal of study convinces me it will have a better than stock weight balance (with the battery moved to the trunk and a few other up front weight saving tricks). With wider tires and perhaps upgraded brakes, it should be a light, balanced, and very powerful sports car.
I will start this later this year. I have the money, but need to find the victim (the car) at a bargain price and do a lot more research on the specific aftermarket parts, etc., which is half the fun.

Again, comments and anything else would be appreciated.
 

·
Registered
Joined
·
102 Posts
what do you plan to do about fuel and spark management? are you going to use an aftermarket controller or go old-school by using a carb and distributer?
 

·
Registered
Joined
·
57 Posts
Discussion Starter #3
I'll go with an aftermarket controller, I think. I don't know who makes the best for this application: part of the research I'll do in the next few monmths. I've used F.A.S.T. with some LS6s where I needed to go beyond the factory PCM's limits. If they make something that fits I'll; probably go with them. I'll have some problem with emissions testing: the cars OBD computer won't be running anything, so what will it tell the emissions computer? But I've seen this finessed by artful programming and I'm not too worried about it.

it would be fun, however, to re-program the cars stock computer to do this. I suuupose I ought to see if that can be done first.
 

·
First 2000 Sr. Member
Joined
·
1,569 Posts
You definately know alot... I have been looking for someone to discuss the Mallett conversion with in detail.

I do know that is what I want... while I won't race it and won't daily drive it... I still want it to handle well and last. It is going to be my weekend cruise car... and show car. Having the LS2 will be a great show stopper.

Do you recommend the addition of the custom rear axle-shafts, double roller timing chain, engine oil cooler or anything else??? I already am planning on the 3.42 LSD...
 

·
Registered
Joined
·
57 Posts
Discussion Starter #6
todaresqSL2 said:
You definately know alot... I have been looking for someone to discuss the Mallett conversion with in detail.

I do know that is what I want... while I won't race it and won't daily drive it... I still want it to handle well and last. It is going to be my weekend cruise car... and show car. Having the LS2 will be a great show stopper.

Do you recommend the addition of the custom rear axle-shafts, double roller timing chain, engine oil cooler or anything else??? I already am planning on the 3.42 LSD...
My overall recommendation would be to leave the LS2 pretty much stock. Its a bulletproof engine, with gobs of power, and its going or provide more than the car needs and as much as it can possibly handle . A double roller timing chain is needed only if you are going for a really aggressive cam replacement, and I don't recommend that. You might have an underdrive pulley put on it. This frees up a bit of power.

Anything you can do to strengthen the rear end will be money well spent. I also recommend the 3.42 rear axle as the best ratio.

It would spend to get the largest rubber you can on all four corners. At the front you are going to have about 125-150 lbs more on the front axle and so you need bigger rubber to handle it, at the rear you need as much as you can get to handle the power.

It occurs to me that I actually do not know where the battery is on these cars (i've forgotten to check). I've been assuming it is under the hood, and if it is I strongly recommend moving it to the trunk: a fairly simple modification. Batteries weigh about 30 lbs, or roughly 1% of the weight of the car, and moving it means a 55/45 F/R balance becomes 54/46 just like that: every little bit helps.
 

·
First 2000 Sr. Member
Joined
·
1,569 Posts
Cool, thanks for the extra info... the battery will be moved... also, my stereo will add a little bit of weight to the rear... while not taking any weight from the front, will still get a better ratio. :D
 

·
Registered
Joined
·
231 Posts
Lee Willis said:
It occurs to me that I actually do not know where the battery is on these cars (i've forgotten to check). I've been assuming it is under the hood, and if it is I strongly recommend moving it to the trunk: a fairly simple modification. Batteries weigh about 30 lbs, or roughly 1% of the weight of the car, and moving it means a 55/45 F/R balance becomes 54/46 just like that: every little bit helps.
The battery is in the front passanger fender behind the front wheel. It sits pretty low in the chassis.
 

·
Registered
Joined
·
57 Posts
Discussion Starter #9
Mallard said:
The battery is in the front passanger fender behind the front wheel. It sits pretty low in the chassis.

It would be good to move it to the rear 0 down low, too, maybe, but to the rear, definately.
 

·
Registered
Joined
·
5 Posts
Cool idea, reminds me of the CTS caddy with the 3.8L turbo buick.

But even though you don't like 4s, the parts in the stock 2.0L supercharged are more capable than one would imagine. The crank, rods and pistions are all good for 300-400hp stock. The crank is the most impressive, capable of 600-800 stock. In the GM Ecotch build book it's only reccommened to change it out(for an aftermarket unit)once one reaches the 1,000 mark. I know book and reality is different, but I'm only bringing it up since this book is an official book of GM. Every possible GM part number and aftermarket source used to build the engine to different power levels is included, down to the sticker for the oil cap!

Also the interesting thing is the block doesn't need to be o-ringed according to GM for the power your looking for. Sure I'm basing alot of what I have said off of this book, but I would like to think that GM knows how to build the ecotech, just look at the salt falt cars they've built so far. Granted I too would actaully o-ring the block just as a safety measure.

But anyways, enough of that. What would you do for a transmission? Auto or manual? If manual, what will you use since if I remember right you'd have to use an adapter plate to bolt one up to the 3.8L. Also since your setting the engine back, what about shifter placement and and the trans and engine mounts? That's what I would be trying to figure out since I beleive it's what will give you the most headaches.
 

·
Registered
Joined
·
57 Posts
Discussion Starter #11
I understand what you are saying, but 40 years of hot rodding, including boosting GM Gen III and IV engines to two to three times stock output has convinced me of one thing: replacing the bottom end components with quality aftermarket parts is good insurance anytime you are going after more than 50% increase over stock. You also get more durability: my 'vette has all Crower components in the bottom end and Jesel valve gear - even though it is putting down twice the stock RWHP I know the engine is good for 60-70K, no problems.
The same, to some extent, with O-ringing heads. Technically, as long as the deck casting thickness on both head and block is good, you do not need to do it until you get to about 20 lbs boost, but I do it anytime I'm over 1 bar (14.7 lbs).
I realize this is a conservative, never count on "what should work" but always on what "will work with no doubt" attitude. But it means problems don't snow-ball, and you ALWAYS have problems when you hot rod an engine. This way, when something doesn't go right: the injectors stick and it runs lean or one fuel rail clogs and the engine runs imbalanced, or the engine overheats for God-knows what reason or the oil pump just doesn't produce or the nitrous comes on too strong, or whatever (all these are things that have happened to me), you just have a headache and a lot of frustration fixing that problem: the imbalanced running does overstress an already amrginal stock crank and break it, the lean mixture doesn't burn through the tops of stock pistons, etc. and you don't end up with a cascading domino set of big failures.

Anyway, sorry for getting up on my pulpit there. I have no doubt you can get lots of power out of the Ecotek and the Solstice/Sky is going to be one of the great ones to hot rod. I salute and encourage anyone who is going to hot rod the Ecotek, because it fits in with my philosophy and avoids what is my major objection to what many are intending to do with the V8: "Don't try to turn in into a 'vette, guys. 'vettes been done better with 'vettes. Make it more of what it is: that's what I'm looking at - just with a different way, which hopefully will be fun.
 

·
Registered
Joined
·
57 Posts
Discussion Starter #13
Gen IV engines, only two so far: I helped a friend build up an LS2 to about 600 flywheel with an modified Magnusen and meth injection. I know GM claims this is Gen IV but its just a 6 liter LS6 in my book, after taking it apart.
And helped with an Escalade to a little more with a Procharger kit. This had some different lifter geometry than the vette (and the cast iron block, of course). I'm not really a fan of these big boxes, but it does move out with that much power. I'm really worried about durability which is why I was glad they really did a good bottom end. In something this heavy the driver will use the SC a lot, I think: I don't expect a stock bottom end would last. Also this thing really needs (and has) a good engine oil cooler.

I'm looking at the big new V6 in a Malibu SS right now that a friend of my son's has on order. This could be interesting.

And of course five of the LS Gen IIIs.
 

·
Registered
Joined
·
57 Posts
Discussion Starter #15
LS2 Solstice said:
I thought the Gen IV motors were DOD?? Cool.

Jay
Not all of them. The LS2 in the 'vette -- at least the one I took apart and helped rebuild and another i watching with a cam change -- are not. Both had the basic castings and webs or whatever you call it in the central "V" of the block to support the DOD, but it is not DOD. That is why, as I said in my previous post, I consider the LS2 just a 6-liter LS6.

What I would hope to see soon in the LS2 and LS7 is not the DOD but the cam phasor that advances and retards the cam over about a 60 deg angle. Variable valve timing has some real potential, I think.
 

·
Registered
Joined
·
1 Posts
Eco vs. LSx vs. V6

This is just my two cents on this issue, if you build the ecotec then you will not have to change the computer and harness, etc. and the ecotec is proven to be more durable than a 4G63 and is lighter weight and more capable with little modification to make huge power numbers. If you use an LSx There will be some changes made but you will still be able to use the stock gauges and trany and it will only add about 200 lbs to the car and when done right it will not alter the balance of the car by more than a few percent to the front and would be way more fun to drive. On the weight difference between the LSx and the V6 I don't have the exact figure but I do know that the aluminum block vs. the cast block in the trucks(5.3L LS1 based silverado motor) is 100lbs so I don't think that a cast V6 is going to be lighter that the aluminum v8 and for the trouble I don't think that a v6 would be really worth all the trouble that it would take to put it in. If you are looking for improvement than boost the eco if you want a beast than put an LS6 in it.
 

·
Registered
Joined
·
57 Posts
Discussion Starter #19
DanvillePerformance said:
I do know that the aluminum block vs. the cast block in the trucks(5.3L LS1 based silverado motor) is 100lbs so I don't think that a cast V6 is going to be lighter that the aluminum v8 and for the trouble I don't think that a v6 would be really worth all the trouble that it would take to put it in. If you are looking for improvement than boost the eco if you want a beast than put an LS6 in it.
You are right about the V8 blocks. the cast iron 6-liter block I used in my Camaro for the 408 weighed in at 89 lbs more than the aluminum LS6 block I had in there originally (the original engine from my 'vette). But as I said above, I'm not using a cast iron V6 block, but an aftermarket aluminum replacement casting - expensive, but light and strong. All told this V6, at just under 4 liters, should weigh about 100-110 lbs less than an LS1: remember, there is only 3/4 of everything, heads, crank, rods, pistons, etc.

And again, its not JUST weight, although that is important, its about balance. A key for me is that the back end of the V6 will be where the back of a V-8 would be but the front will be a full 5 inches back from where the front of the V-8 would be: ALL the weight savings come from right over the front axle, and the accersories -- close to 100 lbs of AC compresors, power steering pumps, pulleys, belts, brackets, etc, are nowl 5 inches toward the rear versus the V8 OR the stock Ecotec. that will help F/R balance.
 
1 - 19 of 19 Posts
Top