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Is a Kappa the correct type for a project?

7K views 45 replies 11 participants last post by  JohnWR 
#1 ·
I like the way they look. Both Solstice and Sky. I like the way they handle. So when I started looking for a car for a project, a kappa was one of the first which came to mind.

But after over 10 years on the road, does it still up to the task? Or is it getting a bit long on the tooth?

And how well does it take to things like custom powertrains, engine swaps and the like? I'm guessing it is post CAN bus? So electronics will complicate swaps?

Are there any kits available for engine swaps or anything would have to be a custom one of? What about kits for suspension, chassis and the like?

Or am I better of with something like a Miata or old S2000 for such a project?

Thanks in advance for the help.
 
#2 ·
They are still great cars whether you modify them or leave them stock. Lots of folks have done engine swaps. It's all up to your skill, wallet and patience.
 
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#3 ·
You leave this very open ended in terms of what you expect to accomplish, but the primary difference between the kappas and other similar cars is that the kappas actually have frame rails. Generally speaking, that makes it much easier to extensively modify, if you can fabricate parts on your own.

I would recommend you buy and live with one for a few months before you dive in. The things you wouldn't change, like the interior, storage, top, and ergonomics, are an absolute disaster compared to the Japanese. But if you want quirky and different, that may be a good thing.

In terms of bolt-ons, there are really only two big players. I won't promote either of them because that might break forums rules, but you should be able to find them. If they don't have it - you're making it on your own.
 
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#5 ·
Thanks everybody for the replies.

Frame rails, yes. Another advantage is that it is basically a rolling space frame. So seems quite simpler to mod than some or most other cars.

Good to know there are at least some bolt ons. Are we talking engine swap kits here? If so, I'm guessing LS?

Has anything other than LS engines been put in these cars? I saw one with a supra engine. But anything else out there for inspiration?
 
#4 ·
If you plan on doing an engine swap, look for an NA car, not a GXP. Preferably a salvage title car is the cheapest way to go. And there are tons out there with very little damage!! They're usually a lot less and I'm hoping you don't think because you put a special engine in it, it's going to be worth more then what you spent on it.... There was a guy here that did an LS3 swap and had about $25k into the car and it was for sale, within 500 miles of doing the swap for $15k. Don't know if he ever sold it or for how much.

Even something outrageous like a BMW or Supra engine doesn't bring any more money. Good Luck.
 
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#6 · (Edited)
Thanks.

I have seen a supra. But so BMW has also happened?

About getting a NA car, is that only because it will be cheaper or it also makes the swap easier technically?

Oh yes, I'm not expecting to make money on it. You never do. These types of projects are money losers. :)

What is the biggest obstacle in an engine swap with the kappa? Does it already use CAN-BUS ? CAN-BUS was introduced in 2004 but only made mandatory from 2008, when the kappa was already on its way out. Since kappa was introduced in 2005, maybe it doesn't use CAN-BUS yet and still use one of the older GM protocols?

I'm guessing there is no published manual or book on the subject like there is for several other cars?
 
#7 ·
An NA car will certainly be cheaper, but the turbo will has all the options standard that the base model may not, including a limited slip, traction control, and ABS. (Note these are all available on the base model, but were additional cost extras when new.) And the additional vents in the front bumper may come in use for cooling.

One of the suppliers makes a fair amount of what's needed for an LS conversion, but it's still not a direct bolt in, plug and play situation. From what I can tell, the throttle by wire has been the biggest hiccup for some reason. I'm not aware of anyone else offering any other engine kits.

The kappas do use can-bus, but it's not quite as integrated as a brand new car. There have been quite a few people able to divorce sub-systems from it to maintain or delete a certain function. I have no idea how they do so.
 
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#8 ·
To expand on Phil's response, the biggest hurdle is going to be packaging. The Kappa architecture was designed around the Ecotec I-4, and there isn't a lot of room for anything else. The entire car is rather short on space, so even installing additional electronics modules can be a bit of a challenge.

I think you are misunderstanding the CAN requirement. It only requires CAN at the diagnostic port, and there is no specification for universal communication within the vehicle.

There aren't all that many aftermarket parts for the platform for a couple of reasons, I think. One is that the stock components make the cars pretty good out of the box, and there is no universal desire to replace a lot of things. There are deficiencies, and certainly some things that could or should have been done differently, but the improvements that can be made are mostly incremental so there isn't a huge incentive to replaces parts en masse. The second is that there is a relatively small population, with only 100k of the cars made, so there isn't a significant profit to be made.

For engine swaps I think that the LNF discourages many, since it is so easy to get so much power out of it. There really isn't much of a need to replace the engine for power, and the LSx satisfies those who just "need a V8". There have been many discussions here about the value of various engine swaps and the reality is that there are no solid gains to be made with any of them. That leaves those who want to do it just because they can, and that is a pretty small population.

What is your goal for the project?
 
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#9 · (Edited)
You may want to check out the FB Kappaswap group. The focus is on swapping engines (and supporting each other through the process), though most questions/discussions center around the LS.

I don't know how many V8 engine Kappas have been built, but I'm thinking it should be a couple hundred by now? Check out YT, for LS videos, supercharged LS, TT LS Sky, and a couple of Toyota 2JZ swapped one's too. You might want to check out the newest player; Kappahaus as they have installed or helped with several recent swaps.



Generally speaking, the main reason I see people choosing something different is because back in the day car magazines began to recognize that some people were bored of building another Ford, Chevy or Mopar. Then Car Craft and other car magazines started to encourage enthusiast to think outside the box. That's an OK reason, but I think the better reason is that a person should have genuine affection for a specific brand or model that they would like to modify, and not just pick something different to be different.
 
#10 ·
Performance Autowerks does direct swaps in the LS flavor you prefer. They have done them for several years and include everything from LS1 to LS7 with supercharger. They also offer "kits" if you want to do your own swap.

Get a doner car with traction control and stability control. Without that, the car has so much power to weight that it becomes dangerous to drive on the road.

In order to retain the factory TC and stability control, you will want to integrate the engine control module for the LS with the Body Control Module BCM which manages the car including the TC and SC.

You will want a car that has a limited slip differential as the alternative is ugly. Basically that suggests either finding a correctly configured NA or any turbo car.

In order to integrate the ECM and the BCM, the only known / proven solution I am aware of is using LS1 edit. LS1 edit is very old code and most "with it" "modern" tuners hate it. It was developed by a very smart Bell Labs research technician for his own use in his personal car when the LS first became available. Its not very user friendly and a little clunky. But it is the only tool that I am aware of that ensures the LS ECM will integrate fully with the car electronics.

Ken Kelly the author retired and no longer sells or really supports LS1 edit, however, Dave at Performance Autowerks and Dave at DDM Works along with Wade's Garage all have manufacturer's version of the tool and can continue to install and support it for you. Basically, even if you do the work yourself you will likely end up paying Dave at PAW to build your ECM for you. LS1 edit requires a HARDWARE key to function and if you don't already have a key, then you are basically dependent on Dave or Dave or Wade to do the install for you. I have a licensed copy and a key, but the first time you connect to the code, the VIN is loaded into the key and will only work on that VIN unless you have a manufacturers license like the Daves and Wade.

My recommendation is you talk with PAW and see if you can work with Dave. I have used him many times over the years with great success. He is a race car builder and approaches his builds from that perspective but he is probably the most experienced LS conversion shop currently in the business.

The same basic code was used by Mallet for the ~100? LS swaps he did.

My recommendation is you go find a car that already has an LS in it and test drive it. To pay Dave to do the swap turnkey for you is about $25k plus the car. You can buy running, low mileage LS cars for that or less and save yourself a lot no a LOT of headaches.
 
#14 ·
Thanks a lot. Lots of info.

So with the 2JZ swap, was it fully integrated too? Maybe somebody developed a similar tool to LS1 Edit for the 2JZ? Or perhaps found another way around it?

Could another way around be stripping the kappa from all systems and using the engine donor systems instead? Meaning bringing the systems from the engine donor with the engine into the Kappa? This could possibly mean fully stripping the Kappa and bring the engine donor loom in and all systems.

Because it seems like a race build is no problem, as they don't have to keep any of the systems. Just a working engine and gearbox. So if the systems are such a pain and one can live without some of them, doing what I suggest above could be a viable thing and make it easier?
 
#22 ·
An exotic twin turbo V8 ;)

I would still love to know your opinion based on the systems I said I wanted to keep. I have the feeling this is not a topic many know deeply about. But you seem to be very knowledgeable about it. :)

Reason for the project is basically because I already have the powertrain. Well, basically the whole crashed donor car actually. So I started thinking of a new home for the engine. It would be a waste not to. So I thought of the kappa. I thought the kappa would be up for the task. It's a nice chassis.
 
#23 ·
I'd do a Tesla motor swap if I were to do anything that didn't involve the 2.0T. The price to pain ratio for anything else just didn't seem to pan out for me. If you want an LS motor it's easier and probably cheaper to get an older C6 vette. Plus you have a huge aftermarket. If you want straight six turbo then get and E89 series Z4. Really good aftermarket there too.
 
#28 ·
I'm also trying to find more detailed info on the 2JZ swap.
For the 2JZ check out Pantherqs YouTube channel, and scroll back to about four years ago. Or just click on the videos w/a black Solstice in it (though he has about 100 videos of stuff he's into). It appears he does a lot of illegal street racing against other cars w/the Sol. If memory serves correct I don't think his videos are particularly heavy on technical data as far as the 2JZ swap goes. The below video is his last one posted from four months ago.

PAW is the only vendor that I know of that advertises an Kappa LS harness. However I have read negative comments of its functionality so make sure you do your research on it.

There was also a former member (gmtech16450yz) who installed a LSA (supercharged) engine that came out of a Cadillac V Series (mid 2000s). Very knowledgeable & technical guy, but he didn't care for the forum and left after awhile. But you can search the forum for for his old postings.

patherqs 2JZ


gmtech LSA
 
#31 ·
Ok, so what is the process used to build Kappa race cars? They get the engine and car running.

Then adding 3 systems is really that hard? There is no stand alone aftermarket ABS and airbag? Maybe there is not traction control. But something as simples as ABS and airbag maybe?

Otherwise maybe I should look into another platform? Maybe slightly older? I would have thouht the Kappa was old enough, being probably developed in 2004 or so, not too be such a pain in the neck. Guess I was wrong. Probably all that I want to do is doable in a Miata. But I don't like them much and they are quite a bit smaller. Maybe a BMW Z? Or any suggestions for another RWD sports car platform that could make it easier? Something not as small as a Miata but not as large as a Corvette.
 
#35 · (Edited)
Ok, so what is the process used to build Kappa race cars? They get the engine and car running.
You don't want a race car, you said that you want a fully-(or mostly-) functional street car.
Then adding 3 systems is really that hard? There is no stand alone aftermarket ABS and airbag? Maybe there is not traction control. But something as simples as ABS and airbag maybe?
Yes, it really is that hard. Phil summarizes it pretty well above.
Otherwise maybe I should look into another platform? Maybe slightly older? I would have thouht the Kappa was old enough, being probably developed in 2004 or so, not too be such a pain in the neck. Guess I was wrong. Probably all that I want to do is doable in a Miata. But I don't like them much and they are quite a bit smaller. Maybe a BMW Z? Or any suggestions for another RWD sports car platform that could make it easier? Something not as small as a Miata but not as large as a Corvette.
Any chassis that you use is going to have the same basic problems, unless you get something that pre-dates OBD2 in the mid-90s. At that point you won't have the features that are giving you problems adapting to anyway.

The best thing you can do, since you say you have a fully-functional exotic donor car, is to strip the Kappa chassis down to basically nothing, and use all of the components from the donor. Re-machine the uprights for the donor hubs with their wheel speed sensors and for the donor brake calipers. Use the ABS servo system from the donor, along with the fuel system and instruments. You can probably keep the drive axle, but it may be easier to mount the donor's than to adapt the propeller and axle shafts. Engine, transmission, ECU, etc of course from the donor. The HVAC and power windows can probably stay as they are stand-alone, but you will have to re-wire the trunk latch, hopefully with some safety circuit to prevent actuation when the car is moving. Use the airbags from the donor, since adapting them physically to the Kappa is probably easier - and safer - that trying to get the Kappa controller to play well with the donor electronics. Lighting control should probably be from the donor, although clearly you can splice the Kappa lights into the donor harness.
 
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#32 ·
There is a book available (used only at this point) that will tell you how to make a solstice race car, published by GM for the SCCA. I don't have it, but it might cover disabling or modifying such systems.

The rest of your recent comments have me seriously doubting that you would have the ability to pull this off to the level you think you're going to.

Bosch sells an aftermarket ABS/TCS module. It costs $6,500 and it's up to you implement their sensors and hardware.

Here's a link to the best example I can give you of what happens when you try to copy or transfer someone's "simple" airbag and it changes the timing of it by 0.070 seconds.
 
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#33 ·
I'm not aware of any modern engine swap projects that aren't a giant pain in the neck.

That being said I've always thought the Scion FRS was a good looking, lightweight car desperately in need of a real engine. There seems to be a fair amount of LS swap info on those.
 
#40 ·
I'm not aware of any modern engine swap projects that aren't a giant pain in the neck.

That being said I've always thought the Scion FRS was a good looking, lightweight car desperately in need of a real engine. There seems to be a fair amount of LS swap info on those.
I honestly prefer the look of the Solstice and Sky over the FRS-GT86. Besides since they are newer I guess they would be an even bigger pain in the neck to swap. ;)
 
#34 ·
They certainly get more difficult every year.

Fundamentally, you need to keep the body electronics stock and functioning, while tricking them into thinking that any missing components are indeed there and functioning correctly either via basic circuits that will provide the steady-state "on-line" signal they are looking for, some sort of artificial variable signal that you create yourself (arduino boards are popular for this,) or bastardizing the donor car circuits. All of this is very tricky and time consuming because it's pretty much a crap shoot as to figuring out what needs to see who when, and it'll be different for every chassis, even different year to year between similar cars. And just because something works in the garage doesn't mean it will continue to work with a car in motion. The TBW example I referenced earlier for example, may work fine until the car detects slip, at which point it tries to command a different throttle position, is unable to do so, and goes into limp mode.

Once you get that done, the rest is relatively easy, and includes:

Implement and calibrate/tune a stand alone ECU for the engine, attempting to use as many OE sensors as possible.

Use some sort of aftermarket configurable dashboard or generic gauges, piggy backing the ECU input/outputs for things like temperatures and engine speed, and harvesting others such as vehicle speed from a source you come up with.

Re-wire the rest of the car so that you can have things like a radio, power windows, power locks, dome lights, trunk releases, HVAC, etc via something like a Painless kit.
 
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#41 ·
They certainly get more difficult every year.

Fundamentally, you need to keep the body electronics stock and functioning,
I would prefer that too. But it seems to be too difficult. It's looking like a full strip of the chassi, despite being a lot of work will end up being less time consuming,

while tricking them into thinking that any missing components are indeed there and functioning correctly either via basic circuits that will provide the steady-state "on-line" signal they are looking for, some sort of artificial variable signal that you create yourself (arduino boards are popular for this,) or bastardizing the donor car circuits. All of this is very tricky and time consuming
Exactly. It's looking like that.

because it's pretty much a crap shoot as to figuring out what needs to see who when, and it'll be different for every chassis, even different year to year between similar cars. And just because something works in the garage doesn't mean it will continue to work with a car in motion.
One more reason to go the full chassis strip way, I would say?

The TBW example I referenced earlier for example, may work fine until the car detects slip, at which point it tries to command a different throttle position, is unable to do so, and goes into limp mode.

Once you get that done, the rest is relatively easy, and includes:

Implement and calibrate/tune a stand alone ECU for the engine, attempting to use as many OE sensors as possible.
But a stand alone ECU will not be need if I carry over the engine donor ECU, right? Which is what I would do if doing the full chassis strip.

Use some sort of aftermarket configurable dashboard or generic gauges, piggy backing the ECU input/outputs for things like temperatures and engine speed, and harvesting others such as vehicle speed from a source you come up with.
Again not need if I fully strip the chassis and use the engine donor gauges on the dashboard?

Re-wire the rest of the car so that you can have things like a radio, power windows, power locks, dome lights, trunk releases, HVAC, etc via something like a Painless kit.
Ok. Although I might ditch things like power windows, power locks (it's a door car anyway) power mirrors (if it has) etc for shaving weight. I want to try to make the car lighter.
 
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