When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
After speaking to one particular breaker it's been established that the radiator support and rails are the same on the f-type . There are 3 crossmembers available - steel, aluminium AWD, aluminium rwd obviously that's the one we are interested in . I'll get my car up on the lift week and use a Tremel to get measurements off the xkr subframe to see if they match up as I've had another breaker send me through some pics of the f-type measurements. For a part reference we are after T2R21964 / T2R40869 :GX53-5019-BD / GX53-5019-BE
estimated weight reduction would be in the region of approx 45lbs Distance measured at 39\" by breaker
Further measurements apparently this is the one we want it is the first lot of f type subframes that came with hydraulic rack T2P1028 EX53-5019-AH
Cross-reference the measurements both the subframes (hydraulic & electric) have exactly the same mounting points the only way to determine the difference beside part number is the hydraulic rack subframe has single mounting points for the engine mounts whilst the electric has a single mounting point on one side and two on the other
Last edited by steve_k_xk; May 15, 2022 at 04:30 AM.
How did you arrive at the 45 pounds lighter than steel? I’m now seriously considering this while a good portion of the car’s currently torn down. Trying to figure the cost per pound of weight loss.
Regardless of cost, I'd not swap a subframe for a mediocre weight savings. Too much input for little output. Now if a currently installed one was DAMAGED, then there's a possibility.
Estimated the original coming in at 30kg (65lbs) based online calculator aluminium coming in at a third less weight I arrived at 10kg (22lbs) now this is a rough estimate however I did come past one of the retailer's that actually had the subframe listed at 8kg .
Cee Jay I guess this modification isn't for everyone however there are a few of us on here that have the equipment to do these jobs without paying labour so it simply comes down to the price of the item
For someone like myself I tend to like to push the envelope on these cars and see what I can do that has never been done before
Last edited by steve_k_xk; May 16, 2022 at 12:24 AM.
Got the xk up on the lift this afternoon the good news is all the mounting points match up with the f type subframe, I'm just waiting on measurements for the distance between engine mounts to confirm.
Both upper and lower mounting points measure in across at 835mm as well
People spend thousands on lightweight wheels, carbon fibre seats just to shed a few kilos. The subframe swap sounds like a very cost effective way to reduce weight.
Looks like the subframe with dual engine mount points on one side (electric rack subframe) is also confirmed, you would use the two engine mounting points (550mm) that are closest to each other.
HOWEVER if one was to use this you'd have to mount the rack with the two central bolts only as the third upper mounting bolt does not line.
Last edited by steve_k_xk; May 17, 2022 at 08:09 AM.
That's what I'm thinking with aluminium subframe and BC coilovers that's close to 100lbs right there
This is equal to a weight saving of gutting out the interior, and swapping out cast iron brake rotors to carbon ceramic rotors!! How much are carbon ceramic rotors again?
Let me know if its ok for me to swing by your workshop one day and check out your progress!
All on a 4000+ pound car. I guess if you combine it with several OTHER weight reductions you will eventually get to a good point where all these 2.5%s will add up.
I’ve already saved around 500 pounds and in the excitement of chasing further weight loss a Motorsports mate of mine reminded me of something really important: cars are engineered with proper weight balancing and handling. Shifting, adding or removing weight may have negative results rather than positive without adjusting the vehicle design accordingly. For example with a long wheelbase, front engine rear drive, tail happy, front end lift at speed car, removing substantial weight from the front axle will affect aerodynamics, under/over steer and more.
So now I’ve more to consider besides the effort to do this.
Cee Jay, you were there once upon a time. Me too!
I'll bet you'll be doing it again now that your son is working on an XKR!
Yeah, fine, but I tore apart an old 1975 that wasn't doing anyone any good. I got it from 2833 down to 2800 after swapping in a 300lbs heavier engine and trans, and traded out the anemic little rear axle.
Once again, it was a $200 car that I tore apart, not a $30,000 wonderful GT car.
I guess it all depends on How Much ya Got and What Ya Wanna Do with It.
I concede.
F type subframe
