v8 swap help

[Ascinder]

This is why I don't understand the fascination with going the V8 route. If you swap the auto tranny for the AR-5 5-speed you keep TOD, get a more power-capable transmission, and you can bolt up to the Ecotec turbo 4-bangers that (when tuned with the factory kit) make well over 300 HP. That gives you equivalent power plus less weight and better fuel economy.

But you guys are the experts actually turning wrenches. Is there a hole in that theory?

Yes, V-8's have nice fat torque and horsepower curves while turbo 4 bangers have to rev to the moon to get their horsepower and even then their torque is lackluster. There is also the availability and expense. V-8's are produced in such high numbers and have been around so long that practically everyone knows how to work on them or can point you to someone who can. There is a huge aftermarket and knowledge base as the GM LS series has been installed into just about anything that moves. Don't get me wrong, the ecotecs are really great engines, but the VX is a pretty heavy vehicle and you're going to be running that engine pretty hard all the time, where in the same circumstances the V-8 is going to move it around in it's sleep. The ecotec is actually quite a bit lighter too, but I can't say that really adds all that much to it's value here. What's another couple hundred pounds when the vehicle already weighs over 4,000? Gas mileage is never going to be great in a vehicross. I'm sorry, but our vehicle is just not a zippy little commuter car and never will be. We weigh twice as much and take up a lot more space. I think you're mileage might be better with a 4 cyl. but if you have to rev your engine to death every time you do anything, your mileage is going to suffer substantially.

[Ascinder]

Sorry, double post

[tribalvx]

im actually wondering what everyones opinion of using the engine transmisson of a BMW X6... the 3.0 has 300hp. engine bay appears to be the same size and the M series has 500 hp twin turbo. im contemplating doing a swap in 12 months and entering desert races downb here in the southwest. (lots of sand)

[Ascinder]

BMW's are great, but wouldn't a swap like that be expensive, not to mention parts/repairs down the road? Also, what side does the transfer case output sit? How about the AWD system? Seems like a cool idea, but sounds very difficult to execute and retain any of the systems. 8 speeds would be cool as hell to have though, and paddle shifters on a VX would be pretty cool.

[vt_maverick]

Yes, V-8's have nice fat torque and horsepower curves while turbo 4 bangers have to rev to the moon to get their horsepower and even then their torque is lackluster. There is also the availability and expense. V-8's are produced in such high numbers and have been around so long that practically everyone knows how to work on them or can point you to someone who can. There is a huge aftermarket and knowledge base as the GM LS series has been installed into just about anything that moves. Don't get me wrong, the ecotecs are really great engines, but the VX is a pretty heavy vehicle and you're going to be running that engine pretty hard all the time, where in the same circumstances the V-8 is going to move it around in it's sleep. The ecotec is actually quite a bit lighter too, but I can't say that really adds all that much to it's value here. What's another couple hundred pounds when the vehicle already weighs over 4,000? Gas mileage is never going to be great in a vehicross. I'm sorry, but our vehicle is just not a zippy little commuter car and never will be. We weigh twice as much and take up a lot more space. I think you're mileage might be better with a 4 cyl. but if you have to rev your engine to death every time you do anything, your mileage is going to suffer substantially.

Was reading through some old threads and just came across this for the first time (I was still on my epic cross-country adventure when it was posted). Couple thoughts:

• Ecotec Turbo 2.0 reaches max torque at 2500 RPM, max HP at 5300 RPM. I wouldn't call those "rev to the moon" figures - have you seen the chart for an RX-8 or S2000?
• See red above. If the Ecotec makes superior HP and torque at lower RPMs (5300 vs 5400 and 2500 vs 3000) with less weight than the Isuzu 3.5 why would I be running pretty hard all the time?
• See blue. Seems like the VX has an equal chance of being a peppy commuter as it does being a drag strip-blazing race truck, which it seems like is the point of V8 swaps that eliminate TOD.

I'm interested in improving fuel economy and reliability, not the ability to post quarter mile and 0-60 times that I'd have to be on a private drag strip to hit anyway. It seems like in the worst case I'd end up with similar performance to what I have today but with a more efficient and cheaper to maintain engine.

I might have a line on a cheap and complete Saturn Sky Redline so this isn't me being argumentative - I want to be talked out of it before I do something if there are serious flaws in the theories above.

Feedback?

[Chopper]

Keeping the factory TOD is near impossible, there are just so many issues with adapters and control integration with any of the TOD options that its not worth the time, money and aggrivation.

Second that emotion......just dump the lump
save some weight in the process

[ZeroSix]

On the peppiness:
Drag speed off the line is not the same as stability at high speeds. I learned this in my old tuner days that small city zippers or drag setups are lousy at sustained high speeds in general.

Case in point. A properly setup honda 4 banger will beat a v12 lambo in quarter mile runs at a fraction of the cost.

Past a quarter mile,the longer the distance: Byebye honda.

Comfort is another factor. Suspension and mounts soak a lot of wheel HP to be comfortable.