Turbo vs. V8 (overall package)

[BadgerHound]

I wouldn't say the 5 speed is junk and I've had no probs w/ the trans in mine...since it came from bigger Chevy pick ups, etc that had 6s and 8s, it is fine for general street use...Yamatr is right though that first gear is a quick shift and gas mileage does suffer, but then again, I'm not driving it for the gas mileage! Mallett told me when I was there that if you're going to race it, you'll want a beefier drive shaft, 6 spd, and different gear ratios...

either way its all good...the 6 speed option w/ Mallett was available w/ the above options included w/ an LS2, but it was fairly pricey as I recall...they did use the 6 speed on LS3 conversions though as a standard feature

[Flash's Owner]

Originally Posted by jayhawker125 All right now if price is not an option lets have a little debate as to what would be the best overall package for making a 400hp solstice. So I gathered some numbers and found the gxp weighs 2976 lbs. so turbo charging an N/A would weigh about the same and give you 400hp (with our hypothetical turbo company) and a 7.44 power to weight ratio. However if you drop a ls2 into a solstice the weight becomes 3070 lbs. @ 400 horsepower and a power to weight ratio of 7.675. Things to consider for the V8 are: *Excellent throttle response *Power through out the power band *One problem lies in the cars new found front weight bias although is this enough that a new suspension set up can't fix? Things to consider for the turboed solstice are: *The turboed solstice weighs 94 lbs. less then the v8 *Retains the cars 50/50 weight distribution *However turbo cars have a little bit of lag but is it enough to make the heavier v8 solstice pull away? I realize that this topic has been covered before but not into much depth especially on the v8 side. I feel that not enough information has been given on to how well the solstice handles with a v8.

I have thought about this quite a bit. Adding an LS2 to a Kappa increases front weight by 160# and rear weight by 45#.

This takes a stock base manual Solstice to a bit over 54% front weight distribution - better than a Cobalt SS, but definitely moves the balance (IMHO) of the car away from where I personally prefer it, even if you accomodate the changes with appropriate spring rate adjustments and stabilizer bar tuning.

Acceleration actually suffers, too. It gets difficult to put that power to the ground.

I have yet to see a well done brake upgrade kit that dovetails properly into the chassis controls, and the added front mass hurts the balance of the ABS and dynamic rear proportioning. Unfortunately, nobody does chassis controls tuning for aftermarket modified cars, so you get what you get, but you should help that extra front mass with bigger front brakes. Good luck there.

Another thing to consider is the fact that the LS2 will only make the rated power at around standard conditions. At altitude (maybe up to 5000+ feet), or on a hot day, that little turbo will still be making pretty much full power - the LS2 will be wheezing and may be 20% down on power. Chalk one up for turbos. Lower than standard conditions, the LS2 will make more power - but who cares if the temperature is near 40º - summer-only tires will not be able to grip.

Now, if you replace all the body panels with carbon fiber, including the doors, hood, and decklid, and you put a nice strong rear end in a Solstice, and THEN you put an LS7 into it with properly tuned suspension and appropriate tires, and tune controls with someone who knows what they are doing, I think you may have a real gem.

That might be one expensive car, but with stopping distances well under 100' from 60 MPH, skidpad well over 1g, and 1/4 mile at 10.9 seconds and a 0-60 time like a motorcycle (3.3 seconds), you have a true monster car on your hands. LOL

Such a car would weigh about 2840 lbs, be around 53% front weight, and have pretty much about 600 hp (crank).


So, the question is this: is it possible to push a current GXP w/ LNF to 600 hp crank at a 2.0l displacement? I am thinking not without a bunch of changes, but maybe 450 crank is not out of the question with the proper selection of a turbo and some requirements for either E85 or racing fuel. Then, apply the weight savings of carbon fiber to get the weight down to ~2750 lbs. Me thinks YUM.

Then, the extended question becomes this: Why go to all the trouble when you COULD just buy a Corvette Z06, take all the body panels off, "reimagine" a Solstice Coupe-like (maybe even improved) skin in carbon fiber and have a 'Vette in Solstice clothing?

[snaponbob]

Or simply buy a good used 7 liter Z06, and be done with it. Change the body panels ?????? Good GRIEF.

Steve, slight semi hijack - do you have an idea of what the approximate unsprung weights are at the front and rear? I have found a nice spread sheet for calculating suspension frequencies.

[NormSky]

The extra forward speed is going add weight. Not to mention beefier half shafts if the differential will take it. If your going to do racing not sure if the stock hubs are up to the task of the extra weight as even the C5/C6 has available heavy duty aftermarket hubs available.

Norm

Originally Posted by BadgerHound I wouldn't say the 5 speed is junk and I've had no probs w/ the trans in mine...since it came from bigger Chevy pick ups, etc that had 6s and 8s, it is fine for general street use...Yamatr is right though that first gear is a quick shift and gas mileage does suffer, but then again, I'm not driving it for the gas mileage! Mallett told me when I was there that if you're going to race it, you'll want a beefier drive shaft, 6 spd, and different gear ratios... either way its all good...the 6 speed option w/ Mallett was available w/ the above options included w/ an LS2, but it was fairly pricey as I recall...they did use the 6 speed on LS3 conversions though as a standard feature

[mena661]

I am thinking not without a bunch of changes, but maybe 450 crank is not out of the question with the proper selection of a turbo and some requirements for either E85 or racing fuel.

One of the members here is running his Sky RL at 400whp with 93 octane and meth/water injection. Don't know how close that is to 450 hp crank though.

[Flash's Owner]

Originally Posted by snaponbob Or simply buy a good used 7 liter Z06, and be done with it. Change the body panels ?????? Good GRIEF. Steve, slight semi hijack - do you have an idea of what the approximate unsprung weights are at the front and rear? I have found a nice spread sheet for calculating suspension frequencies.

A good estimate is about 105kg front and rear. Front has bigger brakes, but rear has the driveshafts.

You natural frequencies will be around mid 1.3 hz front / almost 1.5ish rear for a stock RedLine or GXP. Wheelhop, depending on what you choose for your tire radial rates, should work out to around 11.5ish Hz.

[wspohn]

One often overlooked advantage to a tubro engine is the schizophrenic nature of the beast.

Other engine formats try to accomplish the same thing in different ways. The V8s that drop a couple of cylinders while crusing is one, a better one is the variable valve timing of NA engines like the Honda VTEC, but I think best of all is the small high efficiency turbo engine, because while they can put out comparable power and torque to an engine twice the size or more in the NA world, when you stay off the gas, they act like an NA engine with modest cam timing and usually get excellent mileage, something the large displacement NA equivalent can never do.

I'm pretty happy with the Ecotec, even though some of the V8 options discussed don't add very much weight to the situation.

[I1ULUZ]

Originally Posted by wspohn One often overlooked advantage to a tubro engine is the schizophrenic nature of the beast. Other engine formats try to accomplish the same thing in different ways. The V8s that drop a couple of cylinders while crusing is one, a better one is the variable valve timing of NA engines like the Honda VTEC, but I think best of all is the small high efficiency turbo engine, because while they can put out comparable power and torque to an engine twice the size or more in the NA world, when you stay off the gas, they act like an NA engine with modest cam timing and usually get excellent mileage, something the large displacement NA equivalent can never do.

I will agree that a small turbo motor has Bi Polar Personality Disorder, but my 6 speed auto C6 gets the same MPG as the 5 speed auto GXP. 11.7 at 120 vs 13.5 at 100.5 now which do you think feels better when you want to go fast?

I've owned a V8 swap car, FC RX-7 it was a lot of fun to build and drive, always got looks but snapping 1/2 shafts was the least amount of fun with the car. When you do a swap like this you will find the weakest link in the platform you put the V8 in if you use the car and not just cruise it. Some just like the attention they get at car shows so it's a perfect car for them.

For the money it's better to get a Corvette than a V8 swap Solstice. Or do like a few on here have get both.

[LatinVenom]

Originally Posted by mena661 One of the members here is running his Sky RL at 400whp with 93 octane and meth/water injection. Don't know how close that is to 450 hp crank though.

Way north of 450 BHP more like 479 - 480 BHP.

[ender]

Well... I was thinking of V8ing my Sol... but I'm already having issues with putting the power down on the stock turbo, Exhaust, Intake, 275's all around and Wester's tune.

I'll probably just finish the GT35R upgrade on my STi. :-) Hmmm... V8 STi...

[mena661]

Well... I was thinking of V8ing my Sol... but I'm already having issues with putting the power down on the stock turbo, Exhaust, Intake, 275's all around and Wester's tune.

Do you have any suspension mods?

[Yamatr3]

Originally Posted by Flash's Owner I have thought about this quite a bit. Adding an LS2 to a Kappa increases front weight by 160# and rear weight by 45#. This takes a stock base manual Solstice to a bit over 54% front weight distribution - better than a Cobalt SS, but definitely moves the balance (IMHO) of the car away from where I personally prefer it, even if you accomodate the changes with appropriate spring rate adjustments and stabilizer bar tuning.

Flashes Owner, I have to ask where your getting your numbers from? They are way off. As most know, Wade from Wades Garage put an LS7 and T56 in his Sol and his numbers were no where near what you are posting. His numbers were, 52.25 front and 47.75 rear. Those numbers are only marginally higher than the stock Sol. Here is his weight pic, I took this from his website.

Originally Posted by Flash's Owner Another thing to consider is the fact that the LS2 will only make the rated power at around standard conditions. At altitude (maybe up to 5000+ feet), or on a hot day, that little turbo will still be making pretty much full power - the LS2 will be wheezing and may be 20% down on power. Chalk one up for turbos. Lower than standard conditions, the LS2 will make more power - but who cares if the temperature is near 40º - summer-only tires will not be able to grip.

Cmon, 20% down, thats a little much. I put my LS on the dyno in 93 degree Florida heat with 90% humidity and was no where near 20% down, maybe 10%. I think your exaggerating a little bit LOL. Granted the turbo's do have an advantage here, but not as much as your implying.

[ender]

Originally Posted by mena661 Do you have any suspension mods?

Just lowering Springs. Eibach, the mild ones. The car's as low as I'd ever want. Especially since the smaller diameter tires (275/35ZR18) lower it even more.

[scoobyless]

Originally Posted by Flash's Owner I have thought about this quite a bit. Adding an LS2 to a Kappa increases front weight by 160# and rear weight by 45#. This takes a stock base manual Solstice to a bit over 54% front weight distribution - better than a Cobalt SS, but definitely moves the balance (IMHO) of the car away from where I personally prefer it, even if you accomodate the changes with appropriate spring rate adjustments and stabilizer bar tuning. Acceleration actually suffers, too. It gets difficult to put that power to the ground. I have yet to see a well done brake upgrade kit that dovetails properly into the chassis controls, and the added front mass hurts the balance of the ABS and dynamic rear proportioning. Unfortunately, nobody does chassis controls tuning for aftermarket modified cars, so you get what you get, but you should help that extra front mass with bigger front brakes. Good luck there. Another thing to consider is the fact that the LS2 will only make the rated power at around standard conditions. At altitude (maybe up to 5000+ feet), or on a hot day, that little turbo will still be making pretty much full power - the LS2 will be wheezing and may be 20% down on power. Chalk one up for turbos. Lower than standard conditions, the LS2 will make more power - but who cares if the temperature is near 40º - summer-only tires will not be able to grip. Now, if you replace all the body panels with carbon fiber, including the doors, hood, and decklid, and you put a nice strong rear end in a Solstice, and THEN you put an LS7 into it with properly tuned suspension and appropriate tires, and tune controls with someone who knows what they are doing, I think you may have a real gem. That might be one expensive car, but with stopping distances well under 100' from 60 MPH, skidpad well over 1g, and 1/4 mile at 10.9 seconds and a 0-60 time like a motorcycle (3.3 seconds), you have a true monster car on your hands. LOL Such a car would weigh about 2840 lbs, be around 53% front weight, and have pretty much about 600 hp (crank). So, the question is this: is it possible to push a current GXP w/ LNF to 600 hp crank at a 2.0l displacement? I am thinking not without a bunch of changes, but maybe 450 crank is not out of the question with the proper selection of a turbo and some requirements for either E85 or racing fuel. Then, apply the weight savings of carbon fiber to get the weight down to ~2750 lbs. Me thinks YUM. Then, the extended question becomes this: Why go to all the trouble when you COULD just buy a Corvette Z06, take all the body panels off, "reimagine" a Solstice Coupe-like (maybe even improved) skin in carbon fiber and have a 'Vette in Solstice clothing?

Your not specifying if your thinking of this as a track car or a street car, race fuel would be out of the question when it comes to most people, and e85 is not available to everyone. Not only that, but you need a much larger injector to run e85 rather than regular 93 octane, I want to say about 50-60% larger and I'm not sure what we have available for the direct injected motor. As it is, to hit 600hp with 93 octane, I'm sure the fuel system would have to be revamped and your starting to lose the oem fit and feel of a car, which is why it may be appealing to do an lsx swap where you aren't pushing things so hard to get the same power. When your getting into those power levels fuel lines need to be looked at, fuel pumps, etc. This is all aside from a turbo which your looking for something larger than a gt35r at that point, maybe a 37r or 40r, the 40 would be a bit on the big side. It can become a pretty involved project for something not as proven and without the power curve of a v8.

That being said I love turbos ( I'm 99% done with a 650+whp gt4088r subaru build for myself) but I also know their limitations. And at this point we're not just talking about turbo limitations, but the limitations of the LNF motor with direct injection. Don't forget, your looking to get 250% the power out of the motor that it was designed for. Usually a far from ideal circumstance and it usually takes quite a bit of work.

As far as brakes and the chassis controls are concerned, this car could use a nice brake setup from the factory, the stockers are pretty sad. Maybe it doesn't need a bbk, but at the least a quality of rotor that can handle a bit of heat. To be honest I don't know exactly how better brakes effect the chassis controls since I don't understand their logic and how they work. If a bbk really effected the chassis controls I would think that you could even run into an issue with a different pad/rotor combo, they should bite harder and should react a bit differently than the factory brakes.

To be honest I agree our brake offerings suck for this car, unfortunately I wont be at SEMA this year, but imo the best people to talk to are Stoptech or Performance Friction when it concerns brakes. Both are small enough to do a complete kit from their factory rather than just selling a caliper to a reseller to make a bracket and kit. Stoptech tends to take a decent amount of time to adapt their caliper to a car using various piston sizes for the caliper to balance the clamping force so they achieve the bias they feel is best for the braking system, definitely a good company I'm just not sure if their is enough interest for them to get involved.

And back to chassis controls, I'm not sure how hard the computer is to crack, but there are a few companies out there who tune awd computers, usually for center diffs, but I'm sure they could have some insight into making any modifications to the chassis controls if they are actually necessary. And really, when your going that far with a car, should you really need abs and other driving aids? Personally I could do without them.

[mena661]

Originally Posted by ender Just lowering Springs. Eibach, the mild ones. The car's as low as I'd ever want. Especially since the smaller diameter tires (275/35ZR18) lower it even more.

I haven't tried it yet but I am told the GXP ZOK sway bars will cure the squirrelly back end. Specifically, it will make the handling more neutral. Might be worth a shot. I think they're $130 each.