Mod list

I've narrowed my Mod list to this:

Kenny Bell Blowzilla charger Ford Motorsport 4.10 gears Borla Cat back exhaust Pro 5.0 short throw shifter Eibach sportline kit

My goal is to have approx 400-430 RWHP.

Any comments/suggestions (pos and neg) welcomed.

Jeff

01 GT FIPK
Reply to
Jeff
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it sounds like you will have one badass gt, and that kb will def get you into your desired hp range

from what i have read, and this may or may not be true, but when you install a roots blower and the torque is so greatly increased down low in the rpm range, the 4.10 gears may be too deep? unless you have the right tire, wot in first may be virtually unuseable. i cannot even hook with my factory

3.55's in my 04 cobra without low psi drag radials.

on the other hand alot of guys swear by 4.10's even on the 03/04 cobras, and even i sometimes feel like the engine would be happier with a lower (higher numerically) gear, for overall driving.

anyway best of luck with your mods

chris

1 of 72 2004 competition orange cobra convertibles

Reply to
Chris Shea

KenneBell is twin-screw, no? Regardless... torque out the wazoo.

-Mike

-- A happy kid behind the wheel of a 98 Mustang GT Cold air intake FRPP 3.73 gears Steeda Tri-Ax Shifter Flowmaster 40 Series mufflers (self-installed woohoo) Hi-speed fan switch

255/60R-15 rear tires Subframe connectors

Reply to
<memset

Funny you should mention that about the 4.10 gears and SC; somewhere I came across that as well and honestly don't know. Something I'll have to research more into before committing. I got decent tires IMO; BFGoodrich g-Force T/A KDW but not for dragging, which is not my intent (for now).

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Jeff

01 GT FIPK
Reply to
Jeff

This on a stock bottom end? What wheels and tires do you plan to run? Are you planning any more rear suspension mods?

On an '01 Mustang GT with the stock bottom end and redline, plus blower, especially a twin-screw, running on street tires, 4.10's are going to eat up a ton of rubber. You'll need more work on the suspension and wheels/tires to put that power down. 3.27's, maybe

3.55's are probably better, 3.73's max.

On the stock motor that kind of power is running just over the reliable limit. The biggest issue is detonation against the hypereutectic pistons and that amount of power is on the edge. Another issue is that the twin-screw is going to make peak torque fast and down low. This is harder on the bottom end than the kind of power production a centrifugal makes. An intercooler will help and a safe tune is a must. With a really good tune and proper care you can keep it going for a long time but you've got to pay proper attention to it 'cause one hiccup in the fuel supply and it will detonate hard. The downside to the nice low end on such a blower is that this is true across the entire power band, and tip in detonation is harder to hear :).

Don't get me wrong, this is a great setup. And it will work. You just gotta be prepared :).

Remember, greed kills motors :).

Reply to
Dan

The good thing about the Kenne Bell 4.6L kits are that they are well thought out and come complete. It includes things like fuel rails, injectors, BAP, chip etc. As long as the boost is kept to around 9-10 psi he should be fine. IMO, the time when allot of low end torque can be a problem is when you're launching on slicks. Other than this, the tires will just spin which relieves the stress on the drive line. Also, the KB, and Roots, blowers don't require you to rev to 5k-6k rpm to get into the meat of the powerband like a centrifugal. This is a plus relative to engine wear and tear and increases the fun factor exponentially. :)

Reply to
Michael Johnson, PE

Forget about the gears. You won't need them with a twin screw blower. In their place install a larger throttle body and a cold air intake. Then to complete the list add a high flow, after market H-pipe. This will get you around 430-440 rwhp/rwtq.

Reply to
Michael Johnson, PE

I think dropping the 4.10's may be a good idea. I can always upgrade the gears after I've had a chance to sample the KB if I'm not happy or greed gets the better of me ;-). Initially I was looking at a major upgrade in one shot, perhaps gradually building up makes more sense :-)

Running under 9 psi should be fine on my motor (crossing fingers). The kb intercooler can be added to the existing model 1700, which is a plus.

Here is a quote from the KB site:

"Contrary to what you may have heard, the calibration/tune (chip) we supply with our kits is dead accurate and repeatable from car to car. The cars DO NOT vary as some would lead you to believe. It is the "other" mix and match products that create the tuning or driveability issues. Then there's those air fuel ratio meter variations. How can we be sure? We've sold hundreds of 9 psi kits that perform flawlessly. We ask for and receive feedback.We KNOW what causes problems with our kits."

What do I have to mod on the engine to allow more than 450HP? Crawling the Mustang forums and Piston (heads?)/rods seem to be on the list.

Reply to
Jeff

I agree. I think 10 psi with an interooler is about the limit.

My reason for mentioning care with the low end with the TS/Roots type blowers is that the problems that can occur with something like a centri at the top end where boost is peaking occurs much sooner. I've met a couple of '03 Cobra owners now that were tuned without this in mind. Both popped motors at around 2.5k to 3k when the car tipped in lean with full timing. Bad tunes for sure (one was a small upper on the stock tune). Both never heard the detonation either but the motors changed sound.

As for the suspension, I wasn't thinking specifically about beefing it up to handle the power, although that's a Good Thing, but more along the lines of thinking about how to actually make that power usable. It's fabulous to have 400+ ft-lbs at 2500 rpms. But it's a pretty big waste if you're only able to use half of it ;). All that's moot from most rolling starts so take that for what it's worth :).

Reply to
Dan

Yeah, 9 psi should be OK with a good tune. However, while KB's got a good reputation I wouldn't put my motor completely in their hands. If you've got a local dyno get it on there and check the tune out where the car lives. That line you've quoted is their marketing lads and their tune may be consistent but I can garantee you it's different on every car and different for every environment that the cars run in. It's conservative and safe but it's always worth checking it out yourself.

To get at or above 450 bhp *safely* you'll need pistons and rods. The block is good and the crank will support quite a bit of power as long as you don't spin it too much. I've seen a couple of 600+ rwhp 2V 4.6s on the stock crank but they never spun over 6300 rpm. Most folks swap out for a forged crank since they are in there for the pistons and rods anyway, but it's not absolutely necessary for the 450+ bhp range.

Reply to
Dan

Hmmmm I'm not sure I understand that Michael, how does driving around low RPMs, under boost, cause less wear and tear than NOT driving around under boost. And I don't drive around town doing 5K RPMs either, but it's there when I want it. I would like to drive my car with a KB on it just to get a comparison, may be in the market for something else someday and I know yours is a 5.0 so they drive a little differently.

p.s. If the fun factor was to go up exponentially I think my head would explode :-)

Reply to
Gill

The Roots and twin screw blowers have to be tuned throughout the rpm range. KB seems to use a fairly conservative tune in their chips. Plus they have tons of experience with programing them in Mustangs.

But it's soooo much fun having more power than you can use. ;)

Reply to
Michael Johnson, PE

Engines wear really accelerates under high rpm. The speed of the moving parts like pistons, rods, crank etc. puts tremendous strain on the block, bearings and other parts. Especially when they change their direction of travel. A KB blown car will make the same power, say at

3,500 rpm, as a N/A engine makes at near redline. Because the blown engine doesn't experience the added stress from parts moving at high speed it is, in total, under less strain. Now looking at both engines at the same rpm then the blown engine definitely has more stress. I know in my LX I can meet my fun factor while driving and never get close to 5,000 rpm. To get the same effect with a centrifugal I would have to regularly run the engine to 5k-6k rpm. One other thing I think the KB provides is a safer street driving experience. Since power is there at any rpm and in any gear you don't have to rely on being at 5k-6k rpm in each gear to feel the power increase. Most cars require a speed of around 90+ mph in third to be close to redline. That isn't practical for driving on public streets. You are basically limited to feeling a substantial power increase in the first two gears. This is why I say the KB's and Roots blowers are great for the street. This isn't meant to say that centrifugals are bad or don't make great power because they do. Also, if you don't need, or want, low end/mid range torque then centrifugals are the ticket.

What I like the most about my LX is to be running along in third gear at

2,000-2,500 rpm, push the pedal to the floor and it just gives you a tremendous rush of acceleration for as long as you want or until redline (which comes on quickly). The feel or a torquey engine that revs freely to the redline like a built N/A engine is just too much fun, IMHO.
Reply to
Michael Johnson, PE

Mine makes close to that. Because the blown

That was basically my point, that running at full boost in all RPMs is more stressful than say, half of max boost in the low/mid RPMs. I

Depends on which centri your talking about, but I understand your point of the KB low-end torque. One other thing I think the KB

I get the feeling that your trying to say centrifugals are digital or something :( On or Off? Most cars require a speed of

My car in third gear, at 45 miles per hour, is making 6lbs of boost. Plenty of fun, and safe I'd say. This is why I say

Again, none or all. Here's my dyno chart,

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I know it's more peaky than a KB would be but it's by all means not unsafe or hard to control on the street.KBs ARE great blowers and I hear the Whipple chargers are also great but they're not the only ones out there. Novi 2000's are really nice blowers as are the Procharger D-1SC's. I may have to upgrade to a D but not sure yet. I got lucky that my charger has not leaked after 25K miles and that's why I don't recommend them to anyone, buuuuut.

Reply to
Gill

The last dyno pull I did with my car made about 240-250 rwhp @ 3,000 rpm. That beats the peak stock number by about 20-30 rwhp but it's the torque that really kicks you in the a$$.

I only see full boost when I want the power. I can also modulate the power easily with the throttle. It is essentially like running a very strong big block engine.

Please don't take my comments as putting down the centrifugal blowers because that wasn't the intent. They are proven performers. However, I think the reason you don't see any major car companies offer a centrifugal from the factory is their lack of low/mid range torque. They also beg the driver to run the engine to redline. Positive displacement type blowers give the average driver a sense of power throughout the rpm range. Americans basically prefer torquey motors.

The cars I have driven and ridden in with centrifugal blowers kind of remind me of nitrous. The power comes on in a flurry north of 4,500 rpm. It's definitely a rush. The twin screw amplifies the N/A power curve more and there isn't a huge rush of power near redline. Also, with the power delivery being based on throttle position rather than rpm I think makes them easier to control and to keep the tires on the edge of traction a little easier. Of course, in the end, which one is best depends on the personal preference of the driver.

My car can make 16 psi of boost at 2,000 rpm and hold it to redline. It is what hooked me on the twin screw blower. I'm just a torque junkie.:)

My last dyno pull showed 460 rwtq at 2,500 rpm at the start of the pull. It held 400+ rwtq to 5,500 rpm. The torque and hp curves are much flatter than the typical centrifugal makes. Also, the KB's seem to run about the same times as centrifugals that make about 40-50 more rwhp. It all comes down to who has the most area under the power curve with other things being equal.

I don't think they're less safe. I think it takes a lot of caution to wring out a centrifugal on the street. To do it in third gear means 90+ mph speeds. The KB gives me the same feel of acceleration you get at

5k+ rpm at lower speeds and rpm. That doesn't make it faster than a centrifugal, just different. This is why steep gears help centrifugals run better because it keeps their rpm window small between shifts.

If I were to go with a centrifugal it would be the Novi 2000 with an intercooler. That is all the blower most street driven cars could ever use. Where the twin screw has really shown itself as a great blower is the '99+ 4.6L GT kits. They currently, and on average, make more hp/torque per pound of boost then about any other blower available short of turbos. They are getting 400-440 rwhp from 9-10 psi of boost on an otherwise stock engine. They are a great match with the 4.6L engines.

Reply to
Michael Johnson, PE

Stop it!!!!!! STOP IT!!!!!!! All this talk about superchargers & such high HP and TQ numbers is making me want to go strap on a blower to my car & end up blowing the motor!! *wahhh* I wish i was rich!!!!!

-Mike

-- A happy kid behind the wheel of a 98 Mustang GT Cold air intake FRPP 3.73 gears Steeda Tri-Ax Shifter Flowmaster 40 Series mufflers (self-installed woohoo) Hi-speed fan switch

255/60R-15 rear tires Subframe connectors

Reply to
<memset

Reply to
Michael Johnson, PE

Well... I'm in college.. and have a decent paying job.. but hopefully that'll improve even more soon. You just..... you just wait!! I'll come to your house in a Ford GT!! hehehe shyeah right.

-Mike

-- A happy kid behind the wheel of a 98 Mustang GT Cold air intake FRPP 3.73 gears Steeda Tri-Ax Shifter Flowmaster 40 Series mufflers (self-installed woohoo) Hi-speed fan switch

255/60R-15 rear tires Subframe connectors

Reply to
<memset

Hey! I resemble that remark. As soon as the last kid leaves home . . . . or maybe before!

Reply to
John

Reply to
Erik D.

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