How much boost will a stock bottom end hold?

[93cobra1928]

School me up on this. I don't know much about boost (turbo or s/c) and was wondering how much my motor could handle. The bottom end is stock except for forged pistons and ARP rod bolts. Before you flame me on the piston comment, yes I know some stockers are forged :jester:

[qkjuicedpony]

The block will split in half before any of the rotating assembly fails.

In my opinion if it is a daily driven car I'd keep it around 5-525rwhp

Keep the tune safe and the rpm's low(under 6500) and it will last a while too.

[EHardy1971]

The block will split in half before any of the rotating assembly fails.

In my opinion if it is a daily driven car I'd keep it around 5-525rwhp

Keep the tune safe and the rpm's low(under 6500) and it will last a while too.
:stupid: I know somebody on this site that turned up teh boost on a certain 331 powered car, lifted a head, and tore a chunk out of the block around a head bolt hole though. :jester:

[93cobra1928]

The block will split in half before any of the rotating assembly fails.

In my opinion if it is a daily driven car I'd keep it around 5-525rwhp

Keep the tune safe and the rpm's low(under 6500) and it will last a while too.

:hmm: I wasn't thinking it couldn't hold that much! I was thinking of trying to put about 450 to the wheels and max RPM of 6500. :banana:

[93cobra1928]

:stupid: I know somebody on this site that turned up teh boost on a certain 331 powered car, lifted a head, and tore a chunk out of the block around a head bolt hole though. :jester:

They didn't happen to do that on a 93 Cobra did they? :D

[qkjuicedpony]

:stupid: I know somebody on this site that turned up teh boost on a certain 331 powered car, lifted a head, and tore a chunk out of the block around a head bolt hole though. :jester:


I know a guy that had a stock shortblock car with afr's and a systemax intake with a novi2000 that made 595rwhp 4 years ago and is still living today never been apart:D:D

[93cobra1928]

So...would you go blower or turbo?

[qkjuicedpony]

So...would you go blower or turbo?



I'd put some gas on it!

Thats just me though.

:jester:

[EHardy1971]

They didn't happen to do that on a 93 Cobra did they? :D
Nope. It was an '88 GT, 04Mach1's actually. QJP was at the track that day too.:D
I know a guy that had a stock shortblock car with afr's and a systemax intake with a novi2000 that made 595rwhp 4 years ago and is still living today never been apart:D:D
Don't post that up on the corral! It's the gospel truth over there that a stock block automatically splits at 500 hp.:lol:

[93cobra1928]

Nope. It was an '88 GT, 04Mach1's actually.

Oh, I was thinking it was QWKSNKE's old car. Thought I remembered reading that in an old thread when I was searching combo's

[qkjuicedpony]

Nope. It was an '88 GT, 04Mach1's actually. QJP was at the track that day too.:D

Don't post that up on the corral! It's the gospel truth over there that a stock block automatically splits at 500 hp.:lol:

Corral can lick my sack!

[EHardy1971]

Oh, I was thinking it was QWKSNKE's old car. Thought I remembered reading that in an old thread when I was searching combo's
Yeah, Dale found out it was cracked when he went into it.

Corral can lick my sack!
I still play around in the lounge over there, but the tech section has turned into total shit.

[qkjuicedpony]

Yeah, Dale found out it was cracked when he went into it.


I still play around in the lounge over there, but the tech section has turned into total shit.



Yeah they tried to tell me I was full of shit in a dyno number thread over there..Even when I posted sheets they said I made them myself with photoshop

[QWKSNKE]

Yeah, Dale found out it was cracked when he went into it.


.

My block didn't crack under boost. The motor was inspected and freshened up when the blower came off the car. It cracked at some point and time on the last combination

I agree with qkjuiced. Keep it around 500 rwhp, good tune, and it will live.

[93cobra1928]

I agree with qkjuiced. Keep it around 500 rwhp, good tune, and it will live.

How much boost to get to 500? 10psi?

[QWKSNKE]

So...would you go blower or turbo?

I would do turbo. Quieter, better mpg, doesn't take a massive fuel system to feed the same hp as a blower car....

And way cooler :D:D

[qkjuicedpony]

How much boost to get to 500? 10psi?

Depends on the whole combo.

[93cobra1928]

Depends on the whole combo.

Look at my sig

[QWKSNKE]

How much boost to get to 500? 10psi?

Depends on the whole combo.

qkjuiced is right.

If you look in my thread "History of the 93" you can see my combo at 14psi

Stock intake, stock t/b, AFM blower cam, AFR 165 heads

[qkjuicedpony]

Look at my sig

An S trim at 12-14psi will probably get you close to 480-490 rwhp with your current combo. If you went turbo I would change the cam for sure.

[93cobra1928]

qkjuiced is right.

If you look in my thread "History of the 93" you can see my combo at 14psi

Stock intake, stock t/b, AFM blower cam, AFR 165 heads

Yeah I read that earlier, I should be close to that.

An S trim at 12-14psi will probably get you close to 480-490 rwhp with your current combo. If you went turbo I would change the cam for sure.

I was thinking the X-303 had too much overlap for a turbo

A Garret T04 V1 should get me where I need....I guess

[EHardy1971]

My block didn't crack under boost. The motor was inspected and freshened up when the blower came off the car. It cracked at some point and time on the last combination

I agree with qkjuiced. Keep it around 500 rwhp, good tune, and it will live.
Ok, my mistake!:nice:

[qkjuicedpony]

Ok, my mistake!:nice:

Yeah STFU Eric:jester:

[EHardy1971]

Yeah STFU Eric:jester:
:lol::finger:

[Dale McPeters]

I was thinking the X-303 had too much overlap for a turbo


Yep to much overlap for a turbo IMHO.

If you can swing the extra cost just buy an after market block and be done with it. Once you get the first one built and get used to the power you will want more......and with a turbo it is way to easy to turn the boost up. :jester:

I had three cracked late model 5.0 blocks in my shop at one time....
I now have a Dart SHP on the engine stand to take their place. :D

[93cobra1928]

Dale I wish i could afford an aftermarket block right now!

If I can piece together a turbo setup I will be keeping it around the 450rwhp mark and doubt I will turn it past 6000rpm.

As far as the cam goes I will either go with an Anderson or similar turbo grind or put the factory cobra cam back in.

[qkjuicedpony]

Just tuned a car yesterday...Stock short block with either a f or x cam(never verified) performer rpm heads,cobra intake and S-trim at 14psi with a water/meth kit


Made 526rwhp through a c4 trans after finished...No chips or tuners used either and drives like a stock car too

[93cobra1928]

Nice numbers. I would think it was the F cam considering the idle quality is really good on that cam. The X, which I have, has a rough idle with the amount of overlap it has.

[93cobra1928]

I just looked up the specs on both cams and there is only 2* difference in the overlap so I guess my thinking is WAY flawed on that!

[TurboPete]

This is a interesting topic b/c Im beginning to put together my fox body build .
I also heard that the main issue obviously was the upper valley that splits down the middle , so I bought the Valley girdle and main girdle.
The block is a stock block with FRPP crank , Eagle forged I beam rods and Forged Arias TW pistons. I got a sweet deal on a Cam motion custom Turbo Cam from a buddy of mine who aborted a Turbo build , but the cam is a bit aggressive but thats ok I can re-use it later when I build a Dart Block. For now Ill use it in the 306 we re-built.
Heads are TW CNC 185cc , and a Victor Jr upper Intake manifold .
This will be a Turbo Car with a Precision Billet 67mm or maybe a 71mm turbo .
Ive been told rpm is what kills them so Im hoping to push at least 16 psi's on c16 thru a c4 and turn the motor 5600 to 5800 no more then that .
Not sure what it will make but Im guessing somewhere around 530 to 550.
I have a very good friend of mine that ran a bone stock shortblock with afr heads , cam and TW Intake with a Masterpower 70mm for almost 2 years , and only runs c16 and buzzes the motor around 5600 car ran 10.06 @ 134.00 thru a c4 .

http://www.youtube.com/watch?v=OEFjMBvx1iU&feature=related


Pete

[93cobra1928]

Nice video! I am hoping to piece together a system for my cobra, still have tons to learn. I hope Coupe will chime in with his knowledge.

[QWKSNKE]

.
Ive been told rpm is what kills them so Im hoping to push at least 16 psi's on c16 thru a c4 and turn the motor 5600 to 5800 no more then that .
Not sure what it will make but Im guessing somewhere around 530 to 550.


I would be willing to bet that 16 psi of turbo boost will be between 575-600 rwhp

[TurboPete]

I would be willing to bet that 16 psi of turbo boost will be between 575-600 rwhp


Thats what I was thinking as well but since the cam thats going in is really more for a 363 ci Turbo set up turning 6800 Im thinking by turning the motor only 5800 should make a little less. In any case if it makes 570 Ill turn the boost down..


Pete

[QWKSNKE]

Thats what I was thinking as well but since the cam thats going in is really more for a 363 ci Turbo set up turning 6800 Im thinking by turning the motor only 5800 should make a little less. In any case if it makes 570 Ill turn the boost down..


Pete

Gotcha. Didn't realize the cam was designed for high revs

[coupe]

The X303 is a bit big for a mild 306 build... and really not needed for your combo if you're going turbo. Stick with something simple and you should be okay... Seen a STOCK mustang GT with stock 5.0 intake, TB, MAF, etc... with a 70mm turbo on fairly low boost make right where you're wanting to be: 480rwhp. It was a little lazy so I recommend a turbo somewhere in the 60-62mm range. I would consider a F303 cam or even revert back to a stock cam for it... it will get you the power no problem as long as the other stuff is sorted out and it's tuned well.

I wouldn't waste money or time on the valley or main girdles... it's just not needed unless you're planning on testing the limits...then it does a good job holding the mess together when it breaks... but it doesn't prevent any breakage.

[93cobra1928]

The X303 is a bit big for a mild 306 build... and really not needed for your combo if you're going turbo. Stick with something simple and you should be okay... Seen a STOCK mustang GT with stock 5.0 intake, TB, MAF, etc... with a 70mm turbo on fairly low boost make right where you're wanting to be: 480rwhp. It was a little lazy so I recommend a turbo somewhere in the 60-62mm range.

Any hope of finding a junkyard turbo in that size or are junkyard builds
pretty much limited to twins?

[coupe]

First, I will forewarn you about trying to "junkyard" a turbo mustang together: Luck plays a big part in going that route and I've never seen anyone with enough luck to actually end up with a decent budget "junkyard" kit that actually works well. You will probably still have a bunch of money in getting it right after encountering problems.

If you're looking to make 450-500rwhp on a junkyard budget, I think you should find a used S-trim Vortech then drop in a 255 pump, some 42's, a bigger MAF, and a tune.

[qkjuicedpony]

If you're looking to make 450-500rwhp on a junkyard budget, I think you should find a used S-trim Vortech then drop in a 255 pump, some 42's, a bigger MAF, and a tune.



This.


S-trims can be had for really good deals right now

[qkjuicedpony]

I wouldn't waste money or time on the valley or main girdles... it's just not needed unless you're planning on testing the limits...then it does a good job holding the mess together when it breaks... but it doesn't prevent any breakage.


This too.

The intake manifold is the best valley girdle you can get...The motor wont fall apart until you take it off:jester:

[Procharged87]

If you're looking to make 450-500rwhp on a junkyard budget, I think you should find a used S-trim Vortech then drop in a 255 pump, some 42's, a bigger MAF, and a tune.

I definately agree, especially if you aren't certain what your final goals are for the car yet. It's a pretty simple bolt on type install and will make a massive difference. If you decide you want something different later on, you can usually get almost all of your money back out of a used S-Trim kit as long as you keep all the pieces together and take care of it. Also, don't forget that once you cross certain power levels, the block isn't the only thing you have to worry about. The trans, chassis, and suspension needs all go up with power levels too.

[93cobra1928]

The junkyard thing was just something I read about, not something I was set on or really planning. I like things that fit right and work like they are supposed to.

Realistically I would be happy with 400rwhp so that everything else will survive. I don't drive the car much and don't dog it when I do, but want that extra power.

Coupe, what turbo would you recommend? I mean specifically. I don't know turbos but have been reading a TON. Also what would you suggest for good reading to learn the right stuff?

[coupe]

For a real fun streetcar, I'd ditch the cam...go with something smaller...under 220º duration (like stock or even E-303). Turbo I would use for that is a straight T4 turbo. P-trim turbine wheel in a .68 A/R housing and a 60-1 compressor. 400-450 rwhp and it would respond almost instantly...

As for good reading...join www.theturboforums.com (http://www.theturboforums.com) and look in FAQ, newbie forum, and turbo tech forum. All good info there. The search function works too.

[93cobra1928]

For a real fun streetcar, I'd ditch the cam...go with something smaller...under 220º duration (like stock or even E-303). Turbo I would use for that is a straight T4 turbo. P-trim turbine wheel in a .68 A/R housing and a 60-1 compressor. 400-450 rwhp and it would respond almost instantly...

As for good reading...join www.theturboforums.com (http://www.theturboforums.com) and look in FAQ, newbie forum, and turbo tech forum. All good info there. The search function works too.

Thanks Coupe!

Hmmmm stock cobra cam back in, boost it with the hairdryer
and smile all day long :metal: