I was wondering if any of you have some advice on how much boost the 4.6L SOHC engine can take without doing too much internal work. From some things I've read, the Kenne Bell twin screw superchargers seem to work very well on the 4.6's and 5.4's...but I talked to a guy in their tech department yesterday and he said they don't sell the kit for my truck with more than 8 lb. of boost. I was thinking more along the lines of 10 lb. but I don't know if that's too much. I have the 5-speed manual trans and I don't really want to liquefy it. Does anyone also know how well the 5-speed works with superchargers??? Every story on supercharged F-150's I've read in magazines features vehicles with automatics and I was wondering if the trans should be beefed up becuase a guy told me it was kind of weak. Any good advice would help.

Thanks, Adam

 

What gears were you thinking of installing? I think mine already has 3.73 gears which should be good enough. 4.10 is probably too much don't you think?

 

Crash will be along to answer this question. He has a magnacharger installed on his 5 speed, and the tranny holds up fine. (I've questioned him numerous times on it).

I will hopefully be able to convince myself to spend that much money on a S/C for by summer. What I'm looking into right now is changing the gears in the 5-speed. Those gears just erk me for some reason.

 

crash (or anyone with a 5 speed) - How do you like the gearing of the transmission?

I don't like the fact at how high the first gear is and some of the other gears bother me also. I know and understand that it is used for that granny gear to get the truck rolling when your towing something. But I never tow anything and it bothers me that it's so how high. In order to get the truck up to 20 in first gear I have to wait til over 3000 rpm's to shift.

Other things, when I shift from 1 to 2, 2 to 3, and 3-4 the rpms drop by about 700, which I like. But when I shift from 4 to 5 it only drops a little under 500 rpms. That doesn't seem like enough of a drop for a overdrive/ highway /cruise gear.

I've never felt like I have lack of power in any gear though, even when driving on a highway in 5th I found that a touch of the gas peddle and the truck pulls enough so I don't have to downshift to 4th to get power like other cars and trucks.

 

Supercharger, good....

Seriously, have you considered NOS? Certainly less $$$, less involved, comparable H.P..

Just a thought.

http://web.tampabay.rr.com/tampasvt/

[This message has been edited by TampaBayLightning (edited 01-05-2001).]

 

I have the KB supercharger with a 5 speed. I've had lots of problems with the supercharger itself but nothing else. I run 4.56 gears with 36" tires and tow a 4000 pound boat 5 days a week in the summer and I've never had a problem. I also climb around in the mountains alot and play in the snow with both ARBs locked in without a problem. I think if somebody says the 5 speed is week, they are smoking crack.

------------------
hytek1dr@yahoo.com
http://www.geocities.com/MotorCity/Freeway/7515/

 

crash - I have a 3.55 rearend with only 30" tires, believe me I shift out of first very quick, it takes a little over 3000 rpms just to reach 20mph, and I want a S/C to add more power. Thats why I'm looking into trying to change tranny gears.

I didn't know you only had 3.08's in yours, planning on changing anytime soon?

------------------
black 97' x-cab 4x4, 5 speed 4.6, black westin nerf bars, pilot ground searchers, borla SS split rear exhaust, K&N genII, bosch +4 plugs, superchip, flexalite electric fan, v-tech oval side window covers, IAS shocks

premier 720, pioneer 6cd changer, 12 premier sub, premier componets, 2 soso amps

still to come: new spark plug wires, new rims and tires, maybe a supercharger eventually.

 

I have a 3.73 in my STX and I like it pretty well. I can cruise on the freeway in 5th and don't have to shift down to get power and it doesn't seem like mine needs to be shifted as quickly as yours. I talked to a guy who has a 12 second '98 4.6L and he said a 4.10 gear will work really well with a lot of mods, but if you're maybe just going to add the s/c and a few minor things then a 3.73 should work well.

 

Keyser Soze - I know this may sound strange, but I would rather have my tranny regeared then to have to swap out my 3.55's for 3.73's, especially in a 4x4. From what I read before our trucks trans with a 5-speed is :
1st 3.90
2nd 2.25
3rd 1.50
4th 1.00
5th 0.80

Imagine how our trucks would perform (especially with a S/C) if we had gearing similar to the mustand tremec transmission: 3.27, 1.98, 1.34, 1.00, .68.

I fully understand that things like towing would be out of the question, but I bought this truck for looks, performance, quality, and comfortability, not a workhorse.

Fordman - the more I drive this truck the more I agree with you. This is not a weak 5-speed. It could be better if Ford worked on it an improved it, but thats not gonna happen b/c more and more people buy automatics nowadays, so why put money into R&D for something only a small percentage want.

 

Crash:

Reliability? Putting a SC on a high compression engine(stock) is not going to do anything for reliablilty. That's the reason they limit the maximum boost on most SC kits. Most stock drivetrains can't handle a SC.

To do it properly, you'd have to lower your compression ratio and install forged components. You also have the issues of an intercooler, etc.. A simple bolt on mod, it's not...

AND, Nitrous is not always the last modification. It just happens in that order with Lightnings. It certainly does more for reliability than an improperly prepared engine with a supercharger.

Most stock engines can handle a 100+H.P. shot without problems.

Just my .02


Rich

 

Crash:

One thing I've learned after being on this board for almost two years is that everyone has the right to do whatever they want to their vehicles. I'm not second guessing
your order of modification.

The only reason that I opted to post any information are the comments made by the originator of this thread.

He's being given advice to NOT run more than 8lbs. of boost on a stock engine. He wants 10 POUNDS OF BOOST!!!

I was just trying to bring up the issues of running that much boost on an unprepared engine and offered an alternative. I wasn't suggesting both N20 AND a blower...

Such modifications only require that they are done responsibly. I'm not picking a fight with you. I'd rather take it to the track...hehehehehe

Rich

 

Tampa Bay,

After talking to Cavitt Moon last week, he said I can be safe with 9 lb. of boost on the stock engine. He now uses 13 lb. but he had the block bored .010 over and uses a cobra crank and forged rods & pistons (which I'll probabaly do later). But for now I'll go with a 9 lb. kit. Heck, after I do the internal engine work later, I might add a small shot of N2O as well. I do appreciate all the info here on the board. Later

Adam (Keyser Soze)

 

Keyser Soze - consider following crash and going with a magnacharger. Thats what I'm gonna do, except I'm trying to decide between the magnacharger and the ATI procharger, not sure which type of S/C I want.
You might want to start with a blower that has a lower psi output and work up from there as you feel the need.

TampaBayLightning - nitrous is good, the only problem I have with it is that the bottle runs out when it is on all the time. But it is nice to have instant boost like that.

 

Captain,

I'll probably be going with the ATI Pro Charger with 9 lb. of boost. If I add headers, a chip, mass air, traction bars, drag radials, and the 3"/5" drop I'm planning I think I should be in the mid-high 13 second range.

Adam

 

keyser - the ATI seems like a really good kit, especially from the price, boost and intercooler it come with. The only thing that is steering me away from that kit is that it's a centrifugal so it doesn't produce boost til later in the rpm band. I guess that fact is not that bad considering under heavy acceleration or racing we hit very high rpm's anyway.