Ohmyneck

I'm doing a build up, with a nice Head and cam package and some minor bolt on's but before its said and done... I'm shooting to get some high to mid 11's all motor. I was just concearned about the bottom end. I dont want to build a car that cant take the power so I figured I'd find out how much the stock bottom end will take before i need to worry.

z98

Short answer: more than you're going to throw at it, as long as you don't plan on revving too high.

I don't think a h/c will outgrow your bottom end. Depending on which cam, you will probably be less than 450 RWHP. You'll have to worry about your tranny (A4)/clutch(M6) and rear first.

NataSS Inc

iTrader: (9)

I am at 430rwhp through a moser "9. That puts it at about 525 fwhp and so far *knock on wood* no signs of even phasing the bottom end.

Kevin 276

Mike Brown's Twin Turbo CE was running 9.85 @137 stock bottom end, what about 750rwhp give or take 50...ran over a year with no problems...when he finally pulled it apart to install forged parts, it showed no wear or tear...

PREDATOR-Z

Stay around 6500 rpm and it will outlast a lot of other parts

JZ'sTA

iTrader: (23)

I say you can even go 6800 without any problems. The botton end is very strong until you start throwing a ton of boost of a huge shot of juice.
Make sure it is tuned properly and it will run a long time.

Ohmyneck

How much is the price difference between a moser 12-bolt and a Moser 9" rear? i thought about going with the 9' but if it isnt any better or cost a whole lot more I'll stick with the 12

PewterZ28

iTrader: (1)

We will find out. My Z28 was bouncing off the rev limiter on two passes a few weeks ago. My friend had set the rev limiter at 6800 with Edit but the shifts were supposed to occur at 6500. After two passes of 6800 rpm shifts I called it a night until I could lower the limiter to where I wanted it to begin with (6650).

The next week I got the car shifting right and made 4 passes including a personal best. However, I started up the car a few days ago and at idle a very audible knock could be heard. Putting my hand on the water pump, the knock was very noticeable. I'm all freaked out that I spun a rod bearing that night it was shifting at 6800.

Is that even possible, to damage a rod bearing but then run 4 passes a week later including a personal best?

Kevin 276

All of the ls1tech guru's say why spin the engine so high if stop making power up almost to 7,000? Sure it will take it...

GTA91

iTrader: (14)

Pewterz28- Whats up man? Hate to hear that about your car!


*As for what I've been told, alot of guys have told me to just run some APR rod bolts in a stock bottom end and it should be good for 6500-7000 runs. I'm not too sure about the high end of that (7000rpms) but I know I won't be scared to shift it at 6500-6700. Good luck with it all!

PewterZ28

iTrader: (1)

I'm not convinced yet that it is serious. I really think Jason (Tech) could be right and it could be a tensioner. I listened again and felt different parts of the block. The sound and feel of the tap was only near the water pump, which makes me also think it is not something in the bottom end.

IMO, I've been fairly conservative, always setting my car to shift under 6600 and never having my rev limiter higher than 6800. I have the rev set at 6650 now but I am hitting the rev limiter on my shifts so I'm either going to have to lower my shifts or raise the limiter. First I need to find the culprit of the tap though. I'll look at it some more today at lunch, hopefully it is something simple.

PewterZ28

iTrader: (1)

I lucked out! After further examination it turned out to be just the tensioner. A slightly shorter belt fixed the problem.

Ohmyneck

So basicaly if I go with a H/C package and a 12-bolt my bottom end should hold up just fine? I'm shooting for some mid 11 second times without any nitrous.

PewterZ28

iTrader: (1)

I don't see why not. Hundreds if not thousands on "the boards" have been doing it. Just don't spin too high. I don't know what that number is and it is probably different for each car. Too many factors; mileage, wear and tear, oil levels, etc. Just be as conservative as possible with your shift points without sacrificing too much performance.

Kevin 276

Yeap, without a doubt!

eallanboggs

iTrader: (1)

Are you kidding? It's a 6 bolt. Can you say TOP FUEL?