Yea, but putting a turbo on and running like 3psi on that should be ok. I just dont see how spending all that money for some more MPG is going to be worth it, because with an engine as weak as the one youve got, a TOP professional tune is 110% required, and that is $$$$$.

 

i wouldn't put a turbo on just to run 3 psi

and i already outlined what my motives would be, its not just mpg

im just bouncing idea's around and wondered what you guys had to say...

but honestly if it's going to take away from the original fuel mileage when i'm riding it without booost because of having to get better rods

to boost a car like that is just a great concept, because you'd gett really sweet mileage on highway but still have some punch in the city, was all i was after

which i guess i could get some better mileage on the highway and better punch in the city by going I/H/E, but a turbo would'v ejust been a lot cooler, you know?

 

Eh, u CAN boost it, but its not the best engine to boost. The gas mileage WILL increase when youre not boosting.

 

iv boosted my cx and its ok. the gears are good if the car could push them that high. and the whole comment about the cx and vx having weak rods! the bottom ends from the cx,vx,dx,lx all have the same bottom end. i have personaly seen a d15b7 hold up to 215 hp untuned on nitrious before rod let loose.

 

the CX/VX series were good for 44-50 mpg from the factory back then with their 90ish hp...

similar to the HX series of the 6th gen, but the HX weren't as efficient

 

i was taking to a guy with at 2g gst eclipse that burt 1/4 tank of fuel in about 10 miles at 12psi boost...as far as i know, its stock turbo and fuel system. we were cruising at a little over 135...he was pulling at about 140+ for about 30 seconds.
so....sure..thats some GREAT fuel economy... i know, mitsu isnt honda, but still.
my 2cents as well

 

a quarter tank of fuel is rediculous

plus once you're going 135 the drag on your car is huge, because drag goes up exponentially after like 60 miles an hour or something

so due to drag and boosting 12 psi

he would burn a ****load of gas

idk about a quarter tanks worth though

 

Well sure, any engine can hold an alotted amount of power without blowing up. But obviously the engine didn't last, because the rods went. Nitrous is also a bit different than a turbo system as well, it's either on or off and you can only use it when you have the bottle there ready to go.

bp5213215410, I'm not saying don't boost it, but I think you're confusing yourself with what happens when you DO boost an engine. Since you have to change all of the fuel maps and fuel injection paramaters, you're mileage is going to be going down. And when I say down, I mean waaaaay down. It's no longer going to be a car that runs at 16:1 with 180cc injectors, it will be a car running at 11-14 with ~450cc injectors. If you decide to run an SAFC or god forbid... FMU, the gas mileage will be worse ten fold.

That, and like I said, if you want fuel mileage you're going to need a large turbo that is not going to spool at the flick of the throttle. Problem is, you'll also face making excessive amounts of power that argueably could put a lot of strain on the engine. With a good tune it should last ok, but long gears make for long boost sessions and HOT conditions... which isn't good.

I don't know, do what you want. Either way I really don't think that the D15B7 is a good engine for boost. *shrugs*

Good luck whatever you do.

 

Just to clear up some misplaced statements in this thread about D15 engines:

92-95 VX's came with D15Z1's in them. They share the same stroke, bore, and rod journal diameter (important) as the other USDM D15s. However, they have longer rods of 137mm.

D15B7's are what came in the 92-95 DX/LX, and D15B8's came in the CX. I think the differences between these two are the pistons and the cylinder heads, but they share the same shorter 134mm rods. The result is the B7 makes more power, while the B8 is more fuel efficient.

There are also several variants of JDM D15B's (no number, just D15B). These engine's have the same larger D16 rod journal diameter and rod length (137mm), and therefore are able to accept aftermarket D16 rods.

It should be noted that no aftermarket rod is made for D15's (I'm pretty sure), and aftermarket D16 rods though the correct length, will not fit the D15Z1 crankshaft.

 

Also, I don't think there's much difference in what power a D15 or D16 can endure. They can't have much different thickness.

They're not nearly as strong as forged though. Although I'd recommend to anyone having a back up ride/motor when pushing their daily, if that's your daily bp, it might be paticularly important to you to keep a second block ready in case you do throw a rod.