Because of class restrictions. Some do win in spite of that.



That's a 100% pure drag block as it lacks coolant jackets.

Tremec themselves say that this trans wasn't designed to shift over 7000rpm. I know from experience that this is in fact the case, over our stock redline it will not go into gear no matter what fluid or clutch you use. The only option is to faceplate the trans which is costly, labour intensive and makes it less than street friendly.

Ouch! $9K for the block alone.. That's going to be one pricey engine when all is done.
It's pretty though.. And a big weight savings..

Then FI is a better option IMO.. Less stress on the chassis and easier on drivetrain components.. Too bad they don't have a engine option with a lower CR for easier and safer boostng..

Strange I have taken my Vette my wife her SS and my other LS cars over 7k no problem.

Been there done that watched others here in AZ do it and many met failure even a built one so no thanks.

How much over 7000? I couldn't shift mine at anything over 7500.

I think the max was 7300 or just slightly over I didn't do it very often only autocrossing

What class restrictions? I'm talking about unlimited pro class time attack circuit racing, where there are very, very few restrictions and it's 100% all about who can achieve the fastest lap.

That's also expensive as fuck! lol

There are also billet SR20DET blocks too. The MCA Suspension Hammerhead S13 uses one (with a VET head) and took 3rd in World Time Attack Challenge yesterday.

Yes, because the engine swap puts them in the class that full on super cars or pure race cars are in.


You answered your own question...

Link me to exactly what you're talking about with proof. The biggest time attack event in the world just happened over the last two days in Australia, and the highest class is Pro class. Club Sprint class allows engine swaps, but not cross-manufacturer engine swaps. So, that explains why you don't see LSx swaps there, but the Pro class does not have that same rule. These guys are spending insane amounts of money on one goal, to be the fastest around these tracks, and they are not using LSx engines. They are using light, built small displacement engines with huge turbos and setting world records.

I actually can't think of any LSx swapped cars setting records in the U.S. either. There are fast turbo/supercharged s2000s, fast turbo NSXs, etc. with records..... and there are some fast Corvettes holding records too (they tend to do well on less tight tracks though, due to size & weight), but I can't think of any light FR chassis cars with LSx stuffed into them doing well outside of drifting/drag racing. The NSX is an exception to the light, small displacement trend, because it has amazing handling and stability with the mid-engine layout.

It doesn't seem to be about restrictions. It seems to be about weight, balance, and traction.

If anybody has examples of where I am wrong, I would like to hear them though! I have considered putting an LS1 or LS3 in my 240sx several times, but decided against it since I am more into grip driving than drifting or drag.

EDIT: The top 5, by the way, were:

An Evo, an S15, an S13, an S2000, and an RX7......... all with turbo'd small displacement engines. (These cars finished way ahead of all of the cars in the Nissan GTR class, btw.)

BTW, I am in no way saying an LSx or 2JZ swap is not a great idea for performance or even daily enjoyment. I'm just saying it depends on what you want to do with the car and your goals. It's not necessarily the BEST option for overall performance like some people like to state.

It's the cheapest option to get a lot of torque that's going to break traction (good for drifting) or propel you in a straight line very quickly (drag racing).

In things like Corvettes, it's different, because the platform, balance, suspension, etc. is all built around a specific design and the handling is great.

I just wish the Corvette was smaller and more affordable. A baby Corvette would be an incredible car.

Cross brand engine swap instantly puts a car into Prepared or Modified class under SCCA rules which requires a roll bar that most people aren't going to install on a street car. Prepared class is filled with gutted and race-spec cars that are usually not street legal, and Modified class are usually even more extreme.


At these levels weight savings alone is going to essentially remove a large V8 from the equation (as you've said). If you can make the same power with a lighter car, it's going to be done.