Iron block HP limit with forged internals? 1500+ HP truck
 

I'm debating on building a weekend toy. Either a CRX with max 800whp, most likely less or a single cab short bed truck. The CRX only weighs 1700lbs so it doesn't need much to fly. Already picked up the CRX but doing a last brain storm before it gets expensive. The truck will be minimum 4k lbs, closer to 5k for 4x4. Huge traction advantage to the truck. CRX with 600whp would have the around the same power to weight as truck with 1500whp. Real world truck would win, traction and hp advantage plus wind resistance.

Anyone know if the 4x4 in these trucks are okay with high hp? I see a ton of people go 2wd but I assumed it was because the huge drivetrain loss. Would be nice to avoid needed drag radials on the street.

Anyway, I had no luck searching, everything I find talks about the stock bottom end. I want to know when the stock iron blocks start to let go. Either too much flex or cracks.I'll have a better idea of costs and goals then to make a decision, thanks!

Your google search should have shown people making well over 1000rwhp with stock iron blocks.
cant say ive seen 1500 yet but havent been looking either.

What is the budget? I think you will have more trouble with the 4 bolt heads holding enough boost and blowing head gaskets before you would run into the limits of the block itself.

A 600whp front wheel drive car is no fun to drive at all. your constantly having to fight the car and have little control, at least the ones ive been in

If you put (search site www.ls1tech.com ls iron block max hp) into google with no brackets 43,000 results come up.

If you search enough and have enough money then having 4 bolt heads wont stop you from making tons of hp. (hint look at the diesel and SBF guys)

What i would be concerned about is the caps walking and the cylinders cracking especially on a 6L block.

I will sum up what most guys here will say and that is "dude just buy an lsx block it has provisions for 6 bolts heads"

Building a 600whp build is a different world than a 1500whp build. If you can go basically just as fast with a CRX @ 600whp, I'd go that route hands down and deal with trying to get traction. It will be MUCH cheaper.

1500whp may be a stretch but they will do 1500 crank without spending a bunch of money. Personally I think the truck would be 100% more fun then a CRX, nothing like doing rolling burnouts with a bunch of your friends piled in. My truck does rolling burnouts with a dozen people in it but its a diesel, still be absolutely hilarious fun with a gasser. I've been kicking the idea around of building a burnout box rwd manual pickup and swapping to some 32" slicks when it needs to hook. I wouldn't bother with 4x4 for something you want to race, you can fit plenty of tire to hook in a truck and save a ton of money. Not sure how fast your looking to go but guys easily run 8's in a basic RWD truck platform.

Why not 1500 hp CRX?

THAT would be fun to watch...… become a mushroom cloud...….lol

Because they blow up 3 out of 5 passes lol

I was going to hint at RWD swapping the CRX lol.

My post was entirely under that assumption....RWD LS based CRX

I've seen a few with the CRV drivetrain, certainly different.

I mean, if you're going to decide between 600 horsepower and 1500, why decide that with the 1500 you want it to weigh 3000 lbs more?

Because not everyone likes tin cans, it could have 2000hp but I still don't want to drive a tiny Honda.

That's purely preference....others don't want to drive a tank that takes 4 digit power to make it move :jest:

I would think the clamping force of 4 bolt's per cylinder would limit you long before the block.

And small block Pontiac guys

I've had fast FWD honda's and fast rear wheel drive cars. The rear wheel drive cars are a lot more fun. That being said I miss my forged motor turbo GSR more than any other car I've had, that was mostly due to the ergonomics and how fun it was to whoop LS1 ass in it. But having RWD and being able to hook from a dig and drift through corners is more fun over all.

Plus, I got really sick of the 4 cylinder sound compared to the v8 sound. Oh and torque, it's so nice to have torque.

Doesn't really answer your question but if I were looking at building one or the other, the above would be a big factor for me.

True, why my new car is barely 3200lbs lol But it still needs 4 digit power just because, well why not!

4 bolt TFS heads have made well north of 1500hp and cost $1600, not a bad bang for the buck compared to a 6 bolt block and heads depending on your goals.

When a tiny Honda was one of his options, we can probably take the dislike for high powered tin cans off of the table.