This is topic Max./Safe HP for 04 cobra?????? in forum Tech Talk at Northern California Ford Owners  .


To visit this topic, use this URL:
https://californiafords.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=6;t=013476

---

Posted by throckman69 (Member # 6511) on :
 
I have an 04 cobra w/all the bolt ons you can get. I am doing a KB 2.4 upgrade and am courios as to what is really a safe(if there is such a thing) power range for the cobra bottom end. I am shooting for 600 rwhp. would love more but not quite sure if it's good for the motor. Right now I have steeda CIA,full bassani exhaust,SCT chip and tune,and accufab throttle body to help out the new KB.
 

---

Posted by 93PONY (Member # 60) on :
 
I just tuned a buddies KB 03 Cobra to 683RWHP (STD) & 623RWTQ. (stock shortblock)

I'd recomend a Whipple over a KB. They seem to make a LOT more torque down low. (55+ with the same boost/bolt-ons)

Also remember to upgrade your fuel system.
I just tried a few things on the above 03 & was able to squeeze out that power with stock pumps/lines/rails. KB BAP, wiring upgrade, 60lb injectors, & opening up the systems restrictions.

The 03/04 motors can handle 600RWHP no problem.....assuming a safe tune.
 

---

Posted by throckman69 (Member # 6511) on :
 
wow that's bad ass. I am planning on Apex do the work for me. I am just not rich. I can afford the KB but not a blown motor shortly after. Did you beef up the clutch? and How about the rear end? the more info the better I feel about doing this. I am both excited and nervous. thanks for sharing info w/ me
 

---

Posted by Jmir018 (Member # 1414) on :
 
,.

[ March 03, 2006, 11:36 PM: Message edited by: Jmir018 ]
 

---

Posted by throckman69 (Member # 6511) on :
 
hey 93pony, did you use KB's tune or do your own?
 

---

Posted by JohnB (Member # 969) on :
 
You can have all the RWHP in the world but it doesn't mean squat unless you can get it to the pavement. The weak link in the 03-04's is the IRS. Anything on DR's or slicks, you're asking for trouble...even with just a pulley and filter. Unless of course you just want a dyno-queen, then you'll be just fine.
 

---

Posted by jayl (Member # 185) on :
 
not always johnB, my buddys gone 11.90@119 w/437 rwhp about a million times on nittos cutting 1.80s and never had any issues so far......i think its a lot of the idiots that stay on it through the wheel hop that kills them everytime!
 

---

Posted by baggins (Member # 3957) on :
 
chinis whipple 04 with stock IRS and a slipping clutch ran a 11.2 last weekend........?
 

---

Posted by throckman69 (Member # 6511) on :
 
so say i get my hp that I want. and john b says the irs is my weak link. Is there anyone who makes parts for the IRS to beef it up. Or is it not worth it. Ford must have put it in there for a reason, right? Keep the info coming I appreciate it guys.
 

---

Posted by JohnB (Member # 969) on :
 
Ok, 430ish RWHP and 600+ is a big difference. I didn't say it will blow up on the first pass, but you are on borrowed time. If you're going to do it, why not do it right the first time? Everyone has a buddy or friend that has ran the piss outta their car, still drives it daily, and has no problems. But what do I know, I just fix them.
There are several companies such as Billetflow that make upgrade parts for the IRS. As a minimum, I'd install a front and rear IRS brace, solid bushings both front and rear, and upgraded half-shafts if you are indeed going to run 600+.
 

---

Posted by throckman69 (Member # 6511) on :
 
right on john b. I do have the rear irs brace already. I am no car guru so bear with me. What exactly is the weak link in the irs rear end. I haven't checked yet but billetflow makes upgrade parts that can handle the punishment of 600+ hp. I won't be tracking it soon. just play with it on the streets for a while. While I save for a new clutch/flywheel. I am sure that will be next.
 

---

Posted by JohnB (Member # 969) on :
 
What is the weak link IN the IRS?

The IRS Housing. It will go first. Anywhere there is a rubber mount attached. There are two in the front, on the snout of the housing. There is one on the rear (the Brace bolts to it with the two 15mm bolts). ANY serious flex, these will break. After both of these weak areas are corrected, the only other thing is the half-shafts.
 

---

Posted by throckman69 (Member # 6511) on :
 
I am getting it now. I just went to the billetflow website, but didn't see any half shafts. I saw those irs subframe brackets. Are those the fronts you were talking about? Hey John B thanks man. How do you know so much about all this. I am googling half shafts now.lol
 

---

Posted by JohnB (Member # 969) on :
 
I know there are halfshafts that are deemed "Level 10" but I don't remember who they are made by.
I've pulled just a few rear ends apart.
 

---

Posted by 93PONY (Member # 60) on :
 
IRS is heavy & weak. I'd advise a solid rear end swap if this is a street/strip setup. If it's a roadrace, then you'll probably do better with an IRS.

The IRS is at least 100lbs heavier than a beefed up solid rear end.

Clutch will definately need to be upgraded.
Apex has access to excellent clutches, but they come at a high cost. You can get a VERY good clutch from ProMotion (700hp capable) for around $400. I'd also recomend getting a 26 spline input shaft for the transmission at the same time. It's 50% thicker just after the splines than the stock 10 spline shaft.....which have a tendancy to break from time to time.

The tunes I do are custom. KB's tunes are not ideal. They add/subract timing/fuel based on ACT temps.....with BIG swings from temp to temp. Plus, every car is different, so tunes will be different from car to car.
 

---

Posted by mustanggt5091 (Member # 444) on :
 

quote:

---

Originally posted by throckman69:
Hey John B thanks man. How do you know so much about all this.

---

Because hes the man and doing side jobs on stangs for a long time
 

---

Posted by Jmir018 (Member # 1414) on :
 
you are getting a lot of great info here, but i would also check svtperformance.com that forum is inhabited by some majorly modded cobras. they should be able to give you some info so you can make up your mind on which direction to go.
I had a cobra, never broke a halfshaft but i'm sure it was on borrowed time, was i to get another one again, i would get just get a solid axle.
you can upgrades halfshafts ($1500), bushings($800 or more w/ installation and aligment after)clutches, braces etc etc and it might still brake.
i guess it's about what you want to do with the car. will you even be going to the dragstrip often? if not, there is no real need for you to worry.
good luck and post some pics of your cobra (i was gonna say snake, but that sounded funny )
 

---

Posted by Jmir018 (Member # 1414) on :
 

quote:

---

Originally posted by jayl:
not always johnB, my buddys gone 11.90@119 w/437 rwhp about a million times on nittos cutting 1.80s and never had any issues so far......i think its a lot of the idiots that stay on it through the wheel hop that kills them everytime!

---

not to be a dick or anything, but those numbers are not all that impressive.. a friend of mine goes 11.60s@116 consistently with 1.6s on the stock irs. I'm sure if your friend would start getting those numbers he would start suffering some repercussions too. some cobras just snap the halfshaft without any wheelhop by just launching the thing to hard.
 

---

Posted by JohnB (Member # 969) on :
 
Definitely check out SVTPerformance. A TON of knowledge over there!!

Think long and hard about what your goals are for the car. Be realistic. Just remember, for every action there is a equal and opposite reaction. Mod the engine? Other items *may* fail. Keep it all in perspective...
 

---

Posted by jayl (Member # 185) on :
 

quote:

---

Originally posted by Jmir018:

quote:

---

Originally posted by jayl:
not always johnB, my buddys gone 11.90@119 w/437 rwhp about a million times on nittos cutting 1.80s and never had any issues so far......i think its a lot of the idiots that stay on it through the wheel hop that kills them everytime!

---

not to be a dick or anything, but those numbers are not all that impressive.. a friend of mine goes 11.60s@116 consistently with 1.6s on the stock irs. I'm sure if your friend would start getting those numbers he would start suffering some repercussions too. some cobras just snap the halfshaft without any wheelhop by just launching the thing to hard.

---

never said they were impressive, but the car is street raced almost every weekend......and no problems.....i was just giving an example, and the power level is now 495rwhp.....But its all irrelevant now that a solid rear and twin snails are in boxes!!! but i am glad your friend runs 11.60@116.....its good to see those cars et'ing well for the traps!
 

---

Posted by throckman69 (Member # 6511) on :
 
Great info guy's. thanks much. I will stick with the KB upgrade. Then my next thing to save for will be the rear end. I wish I could jump right into the track scene but my wallet isn't that deep it seems compared to some of the other guys around here. I'll see if I can behave with the new power until I can afford to get on it hard enough to be able to pay for more upgrades/repairs. I'm gonna get all the parts for the KB ordered next week. I have been talking to Ed@Apex. He say's like 3 weeks for the blower and then 2-3 days for install/tune. I can't wait
 

---

Posted by Jmir018 (Member # 1414) on :
 
good luck, enjoy your new power.
 

---

Posted by jayl (Member # 185) on :
 
another friend of ours made 610rwhp w/ a KB setup on 19psi......very very fun ride! i got some video from the in the car, racin some pullied 03/04s/ and some ls1s......fun shit, crazy torque at extremely low rpms!
 

---

Posted by Jmir018 (Member # 1414) on :
 
damn. post the vid up. that thing must be fun to drive!!
 

---

Posted by jayl (Member # 185) on :
 
ill try to get my generic converter to work again.....that car was sick as fuck! makes a "tad" bit more power now! boost without a belt! i should put up some vids w/ KB then after vids w/ 76 GTS
 

---

Posted by RixSikCobra (Member # 5058) on :
 

quote:

---

Originally posted by jayl:
not always johnB, my buddys gone 11.90@119 w/437 rwhp about a million times on nittos cutting 1.80s and never had any issues so far......i think its a lot of the idiots that stay on it through the wheel hop that kills them everytime!

---

Jayl, I'm beginning to think that you don't like me ...I'm one of those "idiots" who stayed in the gas on a wheelhop launch at Sac I can tell ya though, by the time you realize you're wheelhoppin', it's usually too late, it happens that fast. I had no chance to get outta the gas. JohnB can verify the carnage that was once my rear end. I broke the housing completely and driveshaft also fell victim. It was fugly....BUT...JohnB in his usual "help everyone" fashion had my car back on the road in no time...with a IRS brace on this time. I agree with John, gotta upgrade part on the IRS wherever ya can. I'm going with bushings and halfshafts here pretty quick. ...or I'm gonna go with a built solid.
 

---

Posted by throckman69 (Member # 6511) on :
 
Thanks again to all that gave their input for me. I hope someday to meet some of you guy's one day. Mabye at the next Apex meet or something. Hopefully my car will be done by then too. This is a cool site to be part of.
 

---

Posted by jayl (Member # 185) on :
 

quote:

---

Originally posted by RixSikCobra:

quote:

---

Originally posted by jayl:
not always johnB, my buddys gone 11.90@119 w/437 rwhp about a million times on nittos cutting 1.80s and never had any issues so far......i think its a lot of the idiots that stay on it through the wheel hop that kills them everytime!

---

Jayl, I'm beginning to think that you don't like me ...I'm one of those "idiots" who stayed in the gas on a wheelhop launch at Sac I can tell ya though, by the time you realize you're wheelhoppin', it's usually too late, it happens that fast. I had no chance to get outta the gas. JohnB can verify the carnage that was once my rear end. I broke the housing completely and driveshaft also fell victim. It was fugly....BUT...JohnB in his usual "help everyone" fashion had my car back on the road in no time...with a IRS brace on this time. I agree with John, gotta upgrade part on the IRS wherever ya can. I'm going with bushings and halfshafts here pretty quick. ...or I'm gonna go with a built solid.

---

quote:

---

Originally posted by jayl:

quote:

---

Originally posted by RixSikCobra:

quote:

---

Originally posted by jayl:
not always johnB, my buddys gone 11.90@119 w/437 rwhp about a million times on nittos cutting 1.80s and never had any issues so far......i think its a lot of the idiots that stay on it through the wheel hop that kills them everytime!

---

Jayl, I'm beginning to think that you don't like me ...I'm one of those "idiots" who stayed in the gas on a wheelhop launch at Sac I can tell ya though, by the time you realize you're wheelhoppin', it's usually too late, it happens that fast. I had no chance to get outta the gas. JohnB can verify the carnage that was once my rear end. I broke the housing completely and driveshaft also fell victim. It was fugly....BUT...JohnB in his usual "help everyone" fashion had my car back on the road in no time...with a IRS brace on this time. I agree with John, gotta upgrade part on the IRS wherever ya can. I'm going with bushings and halfshafts here pretty quick. ...or I'm gonna go with a built solid.

---

hahaha in all honesty i forgot you did that!! dont take offense to my comments! you have a sweet ride and i hope it makes all the power you want it to! i was just giving examples from what i had seen and my opinion........

---

Shit, no offense taken...I felt like an idiot that night . I'm just glad the half shafts held Tune tommorrow so I'll see if it makes all the power I want it to...I'll post up with the results.
 

---

Posted by newcastle (Member # 4691) on :
 
good info...

http://svtperformance.com/forums/showthread.php?t=231900
 

---