2GRFE and the Infamous DQ250.... What's the deal? pt4
Okay it has been a month, what did you accomplish??? Well, a lot actually.
So last blog post, we showed the adapter plate and the flywheel mounted in the SW20 chassis. We determined a lot of issues and solutions since that last post. So let's dive into it.
1) The driver side mount was created, trashed and recreated several times. I spent a lot of time getting the natural angle of the 2grfe to fit correctly in the chassis. Two issues with this. The fuel filter bracket is in the way of the oil pan on the DQ250. I clipped a corner off that bracket and was able to get the engine/transmission squared in the engine bay, however, it needs to be pushed back 20-25mm or so, to give it room around the movement of the engine/transmission. No big deal luckily, just something to be done.
Also the transmission and the driver side frame rail mount provisions are annoyingly close. After getting the right angle of the engine, it became closer. Hence in my previous post, I had this offset bushing setup. Well I decided against that, despite us to making molds for the bushing. A better solution was decided to remove the mounting boss off the DQ250 that cannot be used anyways (since it always interfered with the mounting of the isolator mount) and used Frankenstein Motorwork's rubber isolator. So he sell's these with his own kit, however he has graciously extended the offer to allow me to use it in my kit.
So why is this important? A few reasons... 1) I do not have to cast bushings to sell in kits, 2) this isolator matches the driver side that most people typically have anyway for this swap. 3) MR2 shop collaboration, who doesn't like that? So after some design work and receiving my test isolator from him, we have decided it is close, but fits! We have added the OEM adjustability too (so hopefully this can work in the future on 3S/5S/2AR setups as well as the 2grfe.
The front and rear mounts are less exciting but have prompted changes. The plan is to connect to the stock isolator locations, so if you are using stock bushings or aftermarket poly bushings, it will all work still. The rear was easy, we just made a 3d printed fixture, laser scanned it, designed some bent plate around it and voila, a mount. Simple right? The front has to wait a bit. I was able to design one prior to the correction of the engine angle but I have discovered the mounting provisions on the adapter plate are just not in a good spot. Since this, they have been relocated to a lower area and when the next adapter plate comes in, I will make the front mounts.
2) Enough about mounts, what about axles? Another tricky part of this swap. First off, you cannot easily or at all use the stock passenger stub axle on the 2grfe. It does not clear the casting of the engine block and a tremendous amount needs to be removed to see if it is even possible to use it. The DQ250 sits inboard to the engine block compared to the E153.
So after countless (what I actually mean is over 100 hours) of trying to get from point A to point B on the axles, we decided to do a custom intermediate shaft to a common CV hub (Honda 27 spline). Why this? Well the turbo MR2 axle hits the block, remember? And the only chance to not hit the block is to step it out by the crank pulley and when you get that far out, the axle is too long. So the idea of using the MR2 axles is out of the question. The Honda 27 spline female CV is small enough to fit tucked into the engine block so someone could get DSS or whoever to make custom axles very easily without any issues. We have yet to figure out a CHEAP solution for this, but the possibility is there.
To combat the block grinding issues, the seal area of the shaft was modified to be smaller and a seal adapter is made to slip into the DQ250. You would cut down the snout of the DQ250 so it doesn't hit the block. The seal can be welded in or retaining compound (I will be testing out the compound since I used to use this stuff all the time in another career for similar stuff). Welding is the other way.
Another issue is the driver side. The MR2 axle is about 1.5" too long, so an adapter hub to the stock DQ250 output flange is a no go. Sorry, these axles will really just not work.
But, we are trying to develop something "new". Lies... Marc actually showed how he did it in a Youtube video, where he mated a 930 CV flange to a stock MR2 outer CV hub. We will be manufacturing a set of these (no welding) to see how they turn out.
Likewise, we are also making an adapter to go from the 27 spline shaft to the 930 flange as well. We have to put it in front of the timing cover, which makes the axle a little short, but the 930 has a lot of articulation, so this does not pose any issue. We may eventually make a 1 piece shaft for the intermediate with the hub on it already, but since we are prototyping, we will not be.
As we design through this crazy build, we realize how many little things it takes to get this to be successful. This is not just buy and adapter plate and it will work. Unfortunately, there has been so many different items, that the availability and testing of this kit is just not there yet. We appreciate all the fans of this build for being patient. We do not want to release a kit that is not ready.