KB pulley change

WillDuhhBeast · Jan 26, 2007

hey guys,

I plan on changing my pulley to a smaller one in the near future. Right now I make 373rwhp, but I'd like to see closer to 400 on just the pulley change.

My question is..

Is Kenne Bell the only place to buy a pulley from? I'm interested in maybe going with a 12lb pulley. I have the 1.7 9lb intercooled kit currently.

Oops, forgot to ask about tuning. Would this need a retune for adding a few lbs of boost.. or could I get by fine without a specific tune?

CENTENNIALSTANG · Jan 26, 2007

BOOOOOOOOOOOMMMMMMMMMMMMM

WillDuhhBeast · Jan 26, 2007

I'm not worried about reliability. It's not going to be driven a lot.

It's only somewhat more risky than what I have already.

saleen556 · Jan 26, 2007

Depending on what octane is available 10 or 11 is about max on pump gas. Otherwise too much timing needs to be pulled. I went with a 10# pulley and went up to 404 on 92 octane with the 1.7. I had it tuned with a 12# pulley and race gas and busted a rod the first trip down the track with NO hint of detonation. Unless you plan on a rebuild in the near future I don't recommend going over 10#s.

hotmustang331 · Jan 26, 2007

You will need a retune with a pulley change.

However, you should be able to get over 400RWHP with 9PSI and full boltons....and a good tune ofcourse. What boltons are you missing? And I think the steeda CIA is good for a few RWHP over the KB unit if you still have the stock KB one.

I personally wouldnt go with a smaller pulley...you can get the desired power with more boltons and a better tune....and almost no change in reliability. Smaller pulley will definatly reduce the engines life.

02LaserRed2V · Jan 26, 2007

^ what he said

retune is necessary.

WillDuhhBeast · Jan 26, 2007

I don't have longtubes, and my mid pipe is still catted. I just don't want to spend another 1000 on exhaust.

I have the BBK CAI, so that should suffice.

I suppose the best bet is to just save for the bottom end for awhile.

What kind of boost would be safe with a forged bottom end? Could I run 14lbs safely? Or would it be better to maybe run 9-12lb's with cams?

My goal is 500-550. I know I'll have to do something with fuel and my MAF will have to be bigger also. Probably have to address rear end issues also.

Over all, I understand that a forged block is inevitable.. but I'm trying to find a way to get a few HP without spending thousands.. just for the meantime.

saleen556 · Jan 26, 2007

You will have a hard time getting 500rwhp out of the 1.7. It just can't push enough air. There tests were done on a stock compression motor with race gas and I believe 23 degrees timing. Most aren't getting over 425 on pump gas and 450-475 on race gas and 12-14# boost.

WillDuhhBeast · Jan 26, 2007

saleen556 said:
You will have a hard time getting 500rwhp out of the 1.7. It just can't push enough air. There tests were done on a stock compression motor with race gas and I believe 23 degrees timing. Most aren't getting over 425 on pump gas and 450-475 on race gas and 12-14# boost.

So you're saying even with cams, the 1.7 can't push out 500rwhp?

WillDuhhBeast · Jan 26, 2007

I just read some stuff from the KB site..

They say that long tube headers make little or no power at all on a KB 4.6. They said they have customer reports from actually losing power with long tubes.

What the hell?

It also explain how exhaust HARDLY improves HP numbers. They said the best they tested was bassani x and catback, and it netted 15 rwhp. They say that just removing the stock cat's nets about 10 rwhp alone.

Am I missing something? I was confident I'd gain quite a bit of hp by replacing the stock headers with long tubes.. but apparently not.

Are they blowing smoke and should I not waste my money on longtubes and a shorty midpipe or should I still go for it?

Will cams help me get closer to my goals?

sgarlic · Jan 27, 2007

Well, KB seems to have a negative opinion in general regarding just about every popular Mustang mod except their supercharger.. I personally take what they say about other modifications with a grain of salt.

Besides a CAI, a straight through muffler like Bassani or Magnaflow will give you a few hp as well, however a set like Flowmaster will likely give you nothing but a sound gain. A catless midpipe will also free up a few torque. That's dyno proven even on N/A cars. These hi-flow cat midpipes will give less gains than a catless.. that's also dyno proven.

saleen556 · Jan 27, 2007

WillDuhhBeast said:
So you're saying even with cams, the 1.7 can't push out 500rwhp?

I would say it's probabley possible with forged internals,stock comp and cams.Normally when going with a forged setup guys are dropping the compression to run more boost.The 1.7 has been shown not very friendly on a lower comp engine when turning the boost up.The IATs get way too high.As far as KB view on exhaust mods I don't believe it.I went from 366 to 404rwhp when I went from 9 up to a 10# pulley and added the bassani headers and x-pipe.

WillDuhhBeast · Jan 27, 2007

So in the end.. best bet says I get some blower specific cams, longtubes and a shorty midpipe and I should see close to 500rwhp on a stock compression forged block?

so really.. I'm only a few grand away from my goal.

I will have to upgrade my injectors, and get a new MAF. Possibly build the rear in the near future (this wont see heavy track time until that's done.)

Anything else I should be prepared for?

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