Newby with blown engine/Whipple

[eleanor06]

Hey Guys,

I “HAD” a 2006 Mustang GT with a Whipple HO Supercharger installed in November of last year. The engine was bone stock and had a Ford Racing dealer tune installed. This last week the engine through a rod through the bottom of the block creating an opportunity for a rebuild. Since it was at an insured vendor when it happened it will be covered by insurance. The offer I am getting from the vendor is to have the engine rebuilt at a reputable engine builder here in state. The engine builder plans to take a Romeo block out of a 2003 cobra and stage it with Eagle rotating assembly, eagle forged rods and Arias pistons. I spoke with Eagle and they stated that the cast crank would be weakest part of the bottom end and be rated at 500HP. The Engine builder has not given me a max HP number but has stated that the Whipple can do 500HP and not cause issue with the engine. I also have the opportunity to upgrade the crank (at my cost/$800.00) now to a forged crank if I so desire.


Guys I am in no way a mechanic and have no idea what the pitfalls might be. Here are my general questions and I appreciate your feedback

Should I be worried about a 2003 cobra block considering what I had was a 2006 block with 21k miles
If I add the forged crank what is the next weakest point on the engine?
What is the new safe HP number now that the bottom end is forged? For example 450HP use to be my safe number. I understand that there are numerous supporting mods needed to do before uping the boost.
The scary part about this is I don’t know what I don’t know, I am not a racer but would like the car to be stronger than what I had.

2006 Ford Mustang
4.10 gears
Whipple Supercharger HO/intercooled and installed by Grand Prairie Ford
Stock suspension
Stock Brakes
21k miles on car before failure
Unused SCT tuner

 

[Chris06GT]

Forged bottom end, built right, balanced in an 03 Cobra block........Up the boost with supporting mods and skies the limit......It's all in the tuning and the precise build of the engine......

There are Cobra's making upwards of 900 with stock blocks, BUT, they are tuned VERY GOOD!!!.......

I am sure some of the other guys on here will chime in.....A lot of them on here are far more experienced than me....

 

[maxpayne]

what exactly happened!were you running 10 psi?was it on the track or just driving around...

 

[eleanor06]

It was reported to me that the failure happened at 3500 RPM driving in the city. I wasn't there and previously had not had issues or heard anything unusual. I tried my best not to freak the hell out and will take his word on what condition it was in, as long as it is fixed free of charge. The tune came from Ford Racing because I had to wait an extra day for it to arrive and watch the tune be put on. The gas was the same gas I have always used that was 91 octane and no Ethanol. (As far as I know)

 

[maxpayne]

It was reported to me that the failure happened at 3500 RPM driving in the city. I wasn't there and previously had not had issues or heard anything unusual. I tried my best not to freak the hell out and will take his word on what condition it was in, as long as it is fixed free of charge. The tune came from Ford Racing because I had to wait an extra day for it to arrive and watch the tune be put on. The gas was the same gas I have always used that was 91 octane and no Ethanol. (As far as I know)

91....I tought you're suppoesd to drive a SC'd car with 93 at least......

 

[rayS197]

why not stick with an aluminator block and reduce the weight than the iron block?? or just order the forged shorblock from FRPP?? just some options.

 

[psfracer]

If you want to eventually run 10s in the 1/4, then get the forged crank now. If your happy with 500 rwhp and everything else stock, then just keep the stock crank.

It really just depends on how hard you want to push the car. But think ahead, because you wouldn't want to put the stock crank in, then next year decide you want an 800 rwhp monster, because then you will have to do it all over.

I know a car where the stock crank ran reliably at 600rwhp, so take that for what its worth......

 

[CataclysmGT]

91....I tought you're suppoesd to drive a SC'd car with 93 at least......

Where did you hear that BS from?

 

[flounderlipps]

I think you should get who ever replacing your motor to give you a 05-09 aluminum block.
Go for the forged crank now.

 

[danbogart]

Where did you hear that BS from?

+1. We dont even have 93 octane in WA state.

 

[one eyed willy]

i would go ahead and do the crank, getting a fully built engine for $800 sounds like a great deal, and should always last you. you wont hve any issues with a 03-04 block,they will need to get some motor mount adaptors but other than that, its pretty much the same deal as what you had.

your next weakest link will be your input shaft on the tranny (are you auto/stick?are they upgrading the clutch?)max i would push is 500 unless you have them upgrade the tranny while its all apart.

 

[EagleStroker]

Our stock cranks are stronger than a typical cast crank, but still no where near as strong as Eagle's 4340 crank. Just the metal is 30% stronger than a forged Cobra crank.

We have customers with these kits well over a thousand horsepower, you'll need a new everything before you'd push the limit of that rotating assembly. There isn't anything wrong with the 03 block, I chose to re use my stock block BUT since you broke a rod that may not be an option!

 

[US-1]

Fuck that Cobra block. No way would I swap an aluminum block for an iron version. In addition, the Cobra block will have to use motor mount adapters. The vendor is buying so insist on a new aluminum block.

I'm also sick of hearing that the stock crank will "only hold 500 hp". Sheer bullshit.

 

[EagleStroker]

Fuck that Cobra block. No way would I swap an aluminum block for an iron version. In addition, the Cobra block will have to use motor mount adapters. The vendor is buying so insist on a new aluminum block.

I'm also sick of hearing that the stock crank will "only hold 500 hp". Sheer bullshit.

You've got to keep in mind what most of our salesman listen to everyday, they can't all be specialists in the 4.6 3v world I was waiting on that comment though. That's also the same reason I re used my block, it's an expensive block lol.

 

[ZmanM3]

91....I tought you're suppoesd to drive a SC'd car with 93 at least......

Where did you hear that BS from?

+1. We dont even have 93 octane in WA state.

Funny, my Saleen S/C'd car makes great power on my JDM 91 octane tune. Now I do run 93 for the most part but that is just added protection.

 

[race4food]

Aluminum block with a Cobra crank and the rest of the parts you mentioned will be near bullet proof....

 

[eleanor06]

I appreciate all the feedback. Here in Oklahoma the only gas available is 91 octane. Most of the gas stations have gone to no Ethanol. Hopefully everything will be better than before and I will ask the guys at B&R performance to give me a conservative tune under 500 HP. Thanks Again.

 

[Vapour Trails]

Wow, another one bites the dust on the FRPP/whipple tune no less. So you obviously weren't driving it, I'd be suspicious of the story. Anyway, looks like you have a great opportunity.

I agree insist on an aluminum block.

 

[Grabber07']

Glad you made it over here Kevin. Very good bunch over here and they know their stuff.

Good luck with the build!!

 

[1FastS197]

the stock 03-04 cobra shortblock is forged already... why would the builder want to pull the internals and replace them with other forged internals? don't get me wrong, eagle is a great product... is the motor blown or something? my brother has a 302 stroker that is eagle crank/rods and CP pistons... has done well... personal opinion, the aluminium block will be ALOT lighter and will support the power just fine