No its a pretty clever question and after thinking about it for a while, I didn't have a good answer.
Heavy VX= bad canidate for a 4 cylinder
I4 smaller/lighter than 3.5L= good weight shed for VX
I4 turbos= possible annoying turbo lag (maybe not since there's 2)
I4 more HP= that's all good
I4 better MPG= also all good
Sky/Solstice short production run= that engine could cost big $$$
Too many pros/cons to make a stance. I think its a great idea as long as the extra 45HP goes to the wheels. Then again the MPG alone may make the swap worth it.
Often top HP numbers don't tell the whole story. For a 2-ton vehicle, torque is an important consideration. It doesn't matter how much HP you generate if it takes 20-seconds getting it from 0-25mph. (IOW if that HP doesn't happen until higher rpms)
Responsiveness is usually a product of cubic inches and compression. OTOH, I haven't driven a dual turbo 4-cylinder.
Hmmmmmmmm....interesting article http://www.caranddriver.com/reviews/...take-road-test There's an upgrade for that 2.0 I4 which consists of an ECU flash and a new MAP sensor. Results: 290hp and 360 lb/ft tq.
The 2008 2.0 engine produces the 260hp @ 5300 rpms, and 260lb/ft tq @ 2000rpms. Considering the VX makes its hp/tq numbers @ 5400rpm and 3000rpm respectively, I think we would be all right
(Source of info: Wikipedia)
Last edited by eternal21 : 01/07/2012 at 03:48 PM
Couple things that I think mitigate the highlighted concerns above. First, if an I4 makes more HP and torque than our 3.5 V6 and weighs less it should be all good. Second, the GXP engine is shared amongst the Solstice, Sky, HHR, and Cobalt so there should be plenty of engines out there. I haven't priced them yet though.
I saw that too, and here's an interesting note. Although the AR-5 is only rated at 260 lb-ft of torque, if you have a certified GM dealership install this turbo upgrade it does not void your factory powertrain warranty. So does that mean the transmission will handle that much more power? Or does the GM warranty not cover the clutch or other parts? In either case GM must believe it will be reliable enough not to piss off upgrade customers.