850-1000hp cobra build

[SouthsideSVT]

Looking into rebuilding my 2003 cobra started with a slight tapping in the head that would come and go bought the car knowing it and was planning on rebuilding it anyways still don’t know what the issue was that caused it but it ended up melting a piston my guess is maybe a loose thrist pin there’s no way of telling right now with it still closed up but anyways just looking for what a good reliable setup would be to make 800-1000 hp open to any suggestions have pictures of previous build and melted piston if you’d like to take a look

 

[badcobra]

I have some questions.

1. Are you mechanically inclined and able to do some of this work yourself?

2. What fuel are you planning to run?

3. What power adder and fuel system are you going to run to make 800-1000?

I would consider finding an aluminum block. Either a WAP, Teksid, or Nemak. The reason I ask about fuel is because I would not do a dished piston, especially if you can run e85. There is some savings on the invoice if you do Fel-Pro 26187PT & 26222PT head gaskets. That price is high on the oil pump gears also. You can do a gt500 pump and billet gears for cheaper. On the cylinder heads, it would be worth considering doing hardened exhaust seats. You could also save a bunch of money if you do the top end assembly/degree yourself.

 

[SouthsideSVT]

1.I know the basics and it’s mostly a learning experience as I go on the shop working on it is right down my road and he is okay with me coming in and working on it with him
2.currently is tuned on 93
3. It’s running dual walbro 342 fuel pumps

I know a 1000hp is a reach but some people do it with ease it seems while others are struggling to even get 700 it makes 700hp now and still had room to go on the past setup going with the same setup it had before is no issue to me the power was enough just wanted to see the extent of what was need to go for more power

 

[badcobra]

1.I know the basics and it’s mostly a learning experience as I go on the shop working on it is right down my road and he is okay with me coming in and working on it with him
2.currently is tuned on 93
3. It’s running dual walbro 342 fuel pumps

I know a 1000hp is a reach but some people do it with ease it seems while others are struggling to even get 700 it makes 700hp now and still had room to go on the past setup going with the same setup it had before is no issue to me the power was enough just wanted to see the extent of what was need to go for more power

Can you run e85? Is it available to you? It's much easier to make that power on corn. You never said what the set is that's on the car now.

 

[Weather Man]

1.I know the basics and it’s mostly a learning experience as I go on the shop working on it is right down my road and he is okay with me coming in and working on it with him
2.currently is tuned on 93
3. It’s running dual walbro 342 fuel pumps

I know a 1000hp is a reach but some people do it with ease it seems while others are struggling to even get 700 it makes 700hp now and still had room to go on the past setup going with the same setup it had before is no issue to me the power was enough just wanted to see the extent of what was need to go for more power

Pushing 93 past 650 is just asking for it. The fuel has to be perfect every single fill up and cool mornings have to be driven with care. Get on E85. The wrist pins specced should have been plenty for your power level. I would bet you will see plenty signs of knock when you open it up.

 

[SouthsideSVT]

Can you run e85? Is it available to you? It's much easier to make that power on corn. You never said what the set is that's on the car now.

E85 is available so it’s not an issue to run it on that but what would that entail for switching over do I need a new fuel system to support it or could I use what I have on it now
What do you think a good setup is for it too is that past setup the way to go or should I change some things
Thanks for the help btw

 

[SouthsideSVT]

Ignore this message

 

[TK1299]

Wow, all that in one sentence

 

[badcobra]

E85 is available so it’s not an issue to run it on that but what would that entail for switching over do I need a new fuel system to support it or could I use what I have on it now
What do you think a good setup is for it too is that past setup the way to go or should I change some things
Thanks for the help btw

If you have e85 available, that should be your only fuel choice. You will need bigger pumps, at least 340's, but preferably some 450's. You will possibly also need larger injectors. What you haven't stated yet is what is the current set up on the car? Does it have a supercharger or turbo?

As I said before, do not do dished pistons. Do a flat top piston for 10.5:1 compression minimum.

 

[decipha]

Doing nothing more than just swapping E-85 in her and retuning would put you at 800hp.

No point in changing what you have. I don't see why they spent all that money replacing the stock parts when it was more than capable. Be sure the engine assembler measures everything and actually calculates the actual compression ratio for you as that is extremely critical for the tuner to know on a 4v.

The most common cause for engine failures is a failing fuel pump. Two 255 pumps aren't going to be safe for E-85 at that power level regardless. Best bet is to toss two stock oem replacement coyote fuel pumps in her and call it done.

 

[Fastback]

If you have e85 available, that should be your only fuel choice. You will need bigger pumps, at least 340's, but preferably some 450's. You will possibly also need larger injectors. What you haven't stated yet is what is the current set up on the car? Does it have a supercharger or turbo?

As I said before, do not do dished pistons. Do a flat top piston for 10.5:1 compression minimum.

Just with E85 you can run 2 points or more higher compression? With the same amount of boost? Did not know that.

 

[badcobra]

Just with E85 you can run 2 points or more higher compression? With the same amount of boost? Did not know that.

Absolutely yes. With just the fuel change, a boosted cobra will pick up 60-100whp. E85 is really liquid gold on boosted cars, not only for more power but also much safer. I run 35lbs boost and make over 1500whp with pump e85.

 

[01yellercobra]

Just with E85 you can run 2 points or more higher compression? With the same amount of boost? Did not know that.

Guy on S197 built an N/A big bore stroker with a compression ratio of 12:1. Just for giggles he threw on an M122 and at stock boost levels made around 700hp with no issues. He ended up pulling the blower off as he wasn't looking for that much power. I think he said mpg was close to stock because the extra compression really helped with the E85.

 

[SouthsideSVT]

If you have e85 available, that should be your only fuel choice. You will need bigger pumps, at least 340's, but preferably some 450's. You will possibly also need larger injectors. What you haven't stated yet is what is the current set up on the car? Does it have a supercharger or turbo?

As I said before, do not do dished pistons. Do a flat top piston for 10.5:1 compression minimum.

It has a 2.9 whipple on it

 

[biminiLX]

It has a 2.9 whipple on it

Which Gen rotor pack 2.9?
Also, that invoice posted from 2015 is what’s in the car and hurt now?
As above, yes most definitely switch to E85 if it’s local to you. E85 turned down will be safer and make power than pump 91/93 turned up.
I think the 2.9 would struggle to make 900rwhp on a stock head 4.6 4V.
-J

 

[SouthsideSVT]

Which Gen rotor pack 2.9?
Also, that invoice posted from 2015 is what’s in the car and hurt now?
As above, yes most definitely switch to E85 if it’s local to you. E85 turned down will be safer and make power than pump 91/93 turned up.
I think the 2.9 would struggle to make 900rwhp on a stock head 4.6 4V.
-J

Honestly not sure I didn’t put the supercharger I can go look but won’t know till tomorrow
And yes the current setup is from that invoice

 

[SouthsideSVT]

Honestly not sure I didn’t put the supercharger I can go look but won’t know till tomorrow
And yes the current setup is from that invoice

How much is the crank rated for I feel like that would be the next thing holding me back from 800+

 

[SouthsideSVT]

I think I’m going to mostly just shoot for 800hp it seems the most feasible according to you guys I only have a 2lb lower on it and could go to a 4lb and switching to e85 it seems that it would put me at about 800hp

 

[SouthsideSVT]

This is what is also on the car

 

[biminiLX]

It’s a strong build, just have the car and engine fully inspected by a trusted shop. Maybe the engine noise is an easy fix.
Then swap it two Walbro ‘Hellcat F90000285’ pumps with some ID1050x injectors and spin that 2.9 til it’s maxed. 800rwhp on E85 and tons of serious fun safe on E85 (don’t even worry if it’s at least E70).
Good luck.
-J