How much power is too much power

[IkFate]

I want to ls swap my 88 528e and am wondering is 505hp to much and will it bend the unibody?

[Bimmerguy2002]

I want to ls swap my 88 528e and am wondering is 505hp to much and will it bend the unibody?

Its been done (not that its old and shouldnt be done), just need to throughly inspect the current chassis for stress cracks in the usual places like the B pillar corner, getting enough tire to put the power down, and having a significantly stronger driveshaft. You would probably want to cage it to increase rigidity to some degree ideally.
Main work is getting headers to clear in the engine bay.
Would love to see more of these being done tbh.

[gwb72tii]

Oxymoron?

[Mike W.]

Oxymoron?

I was waiting for this to go slightly sideways. I'll do my part with a quote from Mark Donohue.

If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower.

[gwb72tii]

I long for the days of the Camel GT series with Donahue, Folmer, Danny Ongias and others. Best time for racing in-some ways with huge horsepower and non-computer fluid dynamics driven aero, just seat of the pants stuff.
I can’t guarantee, but I believe at the height of its success the Porsche 917K driven by Donahue had something close to 1200bhp and weighed less than a VW bug. And pictures of Ongias in the Shadow cars of the day make him look as if he’s driving a go cart with a big V8 stuffed behind his head.
I was living in the socialist republic of California then and would go to Laguna Seca for the race there. Watched a guy hit turn one (2?) at high speed, where there was a bump that would unweight the car. He slid outside the corner, hit the gravel and then the hillside, and launched about 50ft in the air and came down in a huge oak tree. Shit flying everywhere, but the driver walked away.

[gadget73]

I'd say its too much horsepower when it goes from "this is fun" to "this is scary" for the driver. Or alternatively when its just boring to drive because you can't actually make use of it's capabilities.

[Mike W.]

I'd say its too much horsepower when it goes from "this is fun" to "this is scary" for the driver. Or alternatively when its just boring to drive because you can't actually make use of it's capabilities.

In spite of my earlier quote, and mental tendency to think more is always better on power, an argument can be made that it's more fun to drive a slow car fast. Not too slow, though circumstances vary, but going balls out hanging right on the edge is fun. In a fast car it can be harder to balance and you can get in a lot more trouble faster, while not really going much faster.

My '70 Simca 1204 I bring up every once in a while was undoubtedly slow, 60 gross HP in a 2,000 pound car, but it was so well balanced and handled so well it was just tons of fun to drive fast. And believe me, I did drive it fast.

[gwb72tii]

I'd say its too much horsepower when it goes from "this is fun" to "this is scary" for the driver. Or alternatively when its just boring to drive because you can't actually make use of it's capabilities.

In spite of my earlier quote, and mental tendency to think more is always better on power, an argument can be made that it's more fun to drive a slow car fast. Not too slow, though circumstances vary, but going balls out hanging right on the edge is fun. In a fast car it can be harder to balance and you can get in a lot more trouble faster, while not really going much faster.

My '70 Simca 1204 I bring up every once in a while was undoubtedly slow, 60 gross HP in a 2,000 pound car, but it was so well balanced and handled so well it was just tons of fun to drive fast. And believe me, I did drive it fast.

Such as the e30 318is? Light, nimble, motor revs forever, maybe the best 2 door BMW ever built.

[mitch5]

I have a 500+ turbo ls bmw and I would say it is too much. That being said i think the chassis can handle it, I have yet to break one bmw drivetrain component. It’s hard to fit a proper tire In the rear

350 with the turbo 3.5 six was perfect.

[turbodan]

300 rear wheel is a pretty good place to be. More than enough to punt an e28 down the 1/4 in the 13 second range. A moderately boosted M20 or M30 can do that reliably, or you could get there with a lightly modified NA LS motor if you're dead set on an engine swap.

Big power is useless without substantial modification, and the further you go down that road the less of an e28 you have left. The far end of that spectrum would be as much an e28 as the NASCAR version of the Camry resembles the original Toyota version.

As far as a turbo LS would go you're looking at using, I imagine, nothing original forward of the differential. The diff, axles and rear suspension are very strong. You should reinforce the subframe mounting points, at each bushing and the rear differential as well. Ideally, you would get rid of the IRS entirely, build a tubular chassis with a four link rear end and some kind of solid axle. Would be far simpler to just buy an older Camaro and put a turbo in it because that's pretty much where you end up.

[Mike W.]

300 rear wheel is a pretty good place to be.

Dan, what was your old turbo car, HP wise? IIRC it was pushing 400 or some crazy thing? So much it wasn't really fun anymore?

[turbodan]

300 rear wheel is a pretty good place to be.

Dan, what was your old turbo car, HP wise? IIRC it was pushing 400 or some crazy thing? So much it wasn't really fun anymore?

A little over 400 at the rear wheels. SAE corrected was 468 but that correction factor is considered excessive for turbo cars at high attitude.

It was fun but not practical or usable at that power level. It would usually hook up in third gear and really hauled ass on highway. It got into the felony speeds very quickly. Around town though there was almost no opportunity to stretch those legs and getting going from a standing start up until about 70 mph was nothing but wheelspin and banging the rev limit.

The current build, based on the first generation of the original, spools very quickly and still makes use of first and second gear. Boost pressure could be increased even with this relatively small turbo but I find it sufficiently enjoyable as is. It's faster than anything bmw produced in its time and the safety margins are excellent at low boost.

[garageboy]

Maybe I've lived too sheltered of a life, but...

Other than having sex (with women), there's nothing more fun than driving a 520i on the Nordschleife at the limit, or just driving my '88 528e around anywhere in the USA, at its limits. That's my story and I'm sticking to it.

[szacsi72]

In my dictionary,
for the street/personal use:

• When the car becomes unsafe e.g. huge turbo, no brake upgrades

• When you are constantly fighting the car, or its hard to drive, so you start to loose fun

For track use:

• When you start to get worse laptimes, because you can't hit the optimal lines due to fighting the car

My 0.02$. This is of course, a personal "limit". And also depends on your area - condition of the roads, tires, weather etc