Re: what's the difference between vr4 engine and na engine?
I see, so it would be useless to have a vr4 motor in there if you don't plan on doing turbos... It has lower compression so that there would be less knock when turbos are used? Thanks
Re: what's the difference between vr4 engine and na engine?
IT would be a flat out dog if you didnt use turbos. NA's are rated at 222 hp with the 10:1 pistons. Rated being the key word. They probably make 205-210hp at the crank. With 8:1 pistons and no turbos its only going to be like 180hp, so it will be about as good as a SOHC, only with an extra 1000 rpms. Its not worth it just so you dont have to use premium gas. Premium will cost you about $3 more per fill up than 87 and if you cant afford that then sell the car.
Re: what's the difference between vr4 engine and na engine?
The 8:1 compression pistons aren't really designed to reduce knock as much as they allow the engine to push more boost. You would be able to run 9-11 psi (stock for 1st and 2nd gens, respectively) on 10:1 compression, but it probably won't be as reliable for a fleet of engines. (Yes, I know IPO can run 17+ psi, but Mitsubishi doesn't have a warranty on the engine).
There are also a number of other differences between the two engines. The 93+ turbo engines have forged cranks and 4 bolt main bearings. NA (like the 91-92) do not. Also, the turbo engines (not sure if it is 93+, or all years) have additional oil squirters.
Re: what's the difference between vr4 engine and na engine?
Oh yeah, different oil pan too. There's a number of other small differences. You can search to find the specifics. The bottom line is you probably don't want to run a TT block without turbos unless you just have one lying around - and then you would be better off selling it to buy an NA motor (assuming you plan to stay NA).
Re: what's the difference between vr4 engine and na engine?
Quote:
Originally Posted by Hannibalzero
The 8:1 compression pistons aren't really designed to reduce knock as much as they allow the engine to push more boost. You would be able to run 9-11 psi (stock for 1st and 2nd gens, respectively) on 10:1 compression, but it probably won't be as reliable for a fleet of engines. (Yes, I know IPO can run 17+ psi, but Mitsubishi doesn't have a warranty on the engine).
There are also a number of other differences between the two engines. The 93+ turbo engines have forged cranks and 4 bolt main bearings. NA (like the 91-92) do not. Also, the turbo engines (not sure if it is 93+, or all years) have additional oil squirters.
91VR4-3.0L-Stock heads and Cams-835AWHP 747AWTQ Daily Driver 10.31@142mph on street tires
SLTT-10.9 @ 142MPH Stock NA engine and NA heads/Cams
T4 AWD 9.21 @ 154.98 (Chris Hill Driver/Builder/Tuner Car Owned by 3SX)
T2 FWD 10.19 @ 140.31 (Chris Hill Driver/Builder/Tuner Car Owned by 3SX)
T4-159.23 MPH Ran on 6G72 3.1L! (Chris Hill Driver/Builder/Tuner Car Owned by 3SX)
T4-995AWHP Uncorrected 6G72 3.0L C16 (Chris Hill Driver/Builder/Tuner Car Owned by 3SX)
T2-820FWHP 3.1L 27psi C16 (Chris Hill Driver/Builder/Tuner Car Owned by 3SX)
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what's the difference between vr4 engine and na engine?
