Reinforcement of the frame

[ToTallForAnNSX]

So, this is possibly in the wrong section. But I feel like if you're hitting your car with nitrous, you've likely considered twisting the frame.

Roughly at what horse power figure does the NSX start to twist?

Additional question for those who have k series swapped. What intercoolers do you run? I was thinking of doing a air to water and locating jt in the trunk. Is there a more ideal way?

 

[Wild Turkey]

Is twisting a frame a thing with a transverse oriented crank and drive shafts? What would twist and around what axis? The back torque would be forces applied to the engine mounts and twist the engine bay? It mounts pretty thoroughly to the frame, so it would just lift the car at the front ever so slightly, unloading the front springs.

There's no engine putting longitudinal torque (twist) into the frame, unless you rotate the engine 90 degrees & move it to the front.

 

[ToTallForAnNSX]

Honestly? I'm not certain, thats a really good point.

 

[MotorMouth93]

Frame twisting isn't a thing when you have a transaxle bolted directly to the engine, as the chassis is never exposed to the torque created by the engine.

The engine/transmission will try to rock backwards though, so I suppose at some point you could rip the front or rear engine mounts off of the subframe but I've never heard of that happening even on 1000whp+ cars.

But yeah there is a variety of intercooler mounting solutions that don't involve cutting holes in the trunk if you don't want to. SoS offers a bolt in front mounted air to water setup.

 

[Old Guy]

Frame is a bit of an oxymoron on a monocoque body structure.

The drive torque does need to be transferred to the body somehow otherwise the car will not move forward. That transfer is through the suspension upright and the A arms and the engine mounts. In a hypothetical thought experiment, you have to know that if you removed all the engine mounts, blocked the wheels, put the transmission in gear and revved the engine the engine / transaxle will want to rotate around the driveshaft center line in the absence of being able to transfer that motion to the car body. I have no clue as to the split in terms of load transfer between the points; but, I will hazard a guess that the engine mounts are probably pretty important.

So no 'frame' twist; but, there will be distortion at the various load points. That distortion does not appear to be a material issue with the stock engine and I have never heard of performance engines causing a problem. If the engine mounts are not failing its probably well within the design limits of the body load points.

If you want to get your knickers in a twist over chassis twist, take a look at what happens to the body as the suspension points are loaded during cornering or hitting bumps. Take the roof panel off of a Tee roof and drive over some uneven road surfaces and it is pretty easy to spot lateral twist in the monocoque structure.