I bought an 02 subaru wrx really cheap without an engine and looking to swap either a 5.3 or 6.0 into it. It seems the 5.3 is the better choice for gas mileage? What kind of gas mileage difference is there between a 5.3 and 6.0 in a 3000 lb car? Im not too concerned about it, but i'd like to average atleast 24mpg. Ill have to get an ls1 intake and oilpan for clearance. Any issues with hooking up the ls1 injectors to the 5.3 harness? And I may need a different alternator bracket to lower it...not sure. Are they the same as the ls1 bracket? And I assume you can hook up a t56 trans to the 5.3 without any problems, or with the harness? And also, what year range im I looking for to get a 5.3 to work with everything and a t56 trans? I've been researching this, but cant really find good answers to some of these questions.

 

Anyone?

 

Many are likely wondering if you searched.

https://ls1tech.com/forums/conversio...p-lsx-wrx.html

 

I knew about that thread along time ago. Also, he doesn't address the questions I asked. He used a camaro harness, im asking about using the 5.3 truck harness. Same with the rest of it.

 

With an overdrive gear in the transmission you can make your mileage goal with either engine.

 

I have been researching the same swap for some time. It will NOT be an easy one, lots of fab will be needed.

I just finished my first LS swap, in a 96 Impala, which was pretty tame compaired to what would be needed for the WRX swap, and it was still a lot of time and money.

Before I humor you and answer the questions, I will suggest that you do some searching for basic info on the LS family of motors. The accessory mounts are different on car and truck motors, intakes are also different, with variations in the car platforms as well. Most of the basic info can be found with an hour or so of web searches. You will be amazed what you will learn as well as what is similar and useable on all the LS motors.

Don't worry about mileage, you'll be in the ballpark either way, 5.3 will be better, but either will be damn good for a v8.

Oil pan - I have done a lot of research, there are a couple successful swaps, both use front sump oil pans from other GM LS motors, GTO if I recall...Both required some pretty extensive crossmember mods.

LS1 injectors and truck injectors use different plugs, so you will need to modify the harness.

Brackets for accessories are WAY different from truck to car. You will want a car accessory bracket, or F.E.A.D. It won't be cheap, but it will be needed for clearance.

Yes, a 98+ T56 will bolt up, don't buy an older one, it will be more money and trouble than you want to deal with

Any 5.3 or 6.0 will work

Wow, that was a lot of questions.

This will be an intense swap and don't get into it until you have done all your research and you are willing to start cutting your car up. Personally, I would suggest an easier swap first, one with pre-made mounts and exhaust. That or there are lots of Subaru motor swaps that are reasonably priced and easily done in any Subaru car.

Do some heavy research online, but let me know if you have more questions, I've done all the research and there are plenty of very knowledgeable guys on here, but they will be more apt to answer your questions if they are paced a bit more and if you have done the basic research first, because it will show you are more serious.

Good luck

Doug

 

Nothing good can come of this.

I love it!

 

I work at a shop that works exclusively on subarus. Ive got a couple questions. I assume you are going to a rwd conversion? What are you plan for the non drive front suspension and spindles? What rear end or axel do u want to run? Are you wanting to keep it IRS but 2wd? The fab and routing are not that hard for swaps. It only metal afterall . We build alot of race (open track) subarus and I'm pretty savvy in body/suspension knowledge. I might be able to help you out if any problems come up.

 

I just thought of something else also. The wrx/sti platform is very tempromental to front end weight distribution changes. I know the costs increase but I would also consider an aluminum block for you swap.

 

Wow thanks pooge for all the info. I'll be researching more for sure but there's just so much to read and not enough time. I think I'm pretty capable of this swap as I had a truck with air ride on it a couple years ago and did some fairly major fab work on it, including cutting the frame apart and rewelding and making a new tranny x member. I'm fairly new to wiring though.


I'm thinking I may just seal up the holes in the spindles where the axles go, depending if the bearings are exposed to the weather but I won't know until I take the trans and axles out. For right now, I may just stick with the stock diff until I have time to address it, but possibly an sti diff. Haven't really looked into it much yet. And, I may be getting an ls1, which will be lighter, as a friend of mine found one for me, but we'll see. And thanks for the offer, I'll let you know if I have any questions.

 

LSxWRX - Here is an LS swap info thread from a forum I frequent. The first couple pages are very informative before it's starts getting a bit spuratic. You will find lots of great info here for basics and information on the truck vs car accessory brackets and why they can be very important for hood clearance. It will also bring up why you can not use a car accessory brackets on a truck motor without spacer modifications, the Balancer depths are different.

http://www.impalassforum.com/vBullet...d.php?t=228454

sounds like you have some fab skills,so that will go a long way in this project.

As far as wiring goes, there are lots of folks that will build a stand-alone harness for you, but the LS harnesses are pretty easy to do the wiring on compared to others I have researched.

I believe the weight savings from an aluminum block to a iron one is 65 lbs. (I could be wrong, but that number sticks in my head) I have yet to check the weight difference on the T56 trans to the stock Subaru transaxle, but I assume it's pretty close.

Daniel - I am curious about how temperamental the cars are to weight change.... I had a stock 02 WRX for 5 years and loved the car for everything about it, except the lack of low end power and lack of sunroof. I am concerned about the potential for too much front weight distribution, what would be considered too much? I know guys add FMICs and all kinds of crap to these cars, as well as move batteries to the trunk.

The Subaru motor sits well ahead of the front axle and the transaxle only mostly behind the axle, but not fully, where the V8 will sit on the axle with the tranny fully behind it. Shouldn't that help compensate for the extra weight? Or is the weight distribution issue simply front/rear?

Doug

 

if anything id think an lsx/rwd swap would improve distribution.

 

i agree it will be hard, but they do make pre made crossmembers and mounts and money is not an option. https://m.facebook.com/202012099849893/these are the people who make them. TSSFAB

 

You are replying to a TEN YEAR old thread, and Pooge has not been here in that amount of time either.
Please check post dates

 

We don’t need a line monitor. 🙃

 

whatever happen to that kid that was doing a full caged out subie, like welding and plasma cutting the parts in his dorm room?