SaleenGT2001
Well-Known Member
if it makes you feel any better my x pipe hits the trans crossmember and makes a terrible noise at 200-2400 rpm.
foot to the floor to see boost on centri?
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By the time you get everything needed to run the 2.6 properly you are looking at about $3k more than a 2.1.That doesn't include a built motor.
i wish i had a 2.1KB. anybody wanan trade?
But why......you've got soooo much more potential still available in that S-Trim. That bottom end has still got some leeway in it to handle the additional power. Time to add a little water methanol or some sort of air/air after cooler into the mix, swap out that sissy 8lb pulley, beef up the fuel system and introduce it to a new tune. You'd be surprised not only about how much additional peek airflow is available, but at the rate said airflow will introduce itself into the system with a pulley swap and a cooler denser air charge. Pulley that thing for 11-12psi and you'll be into boost before you know it and you’ll pull harder than you ever have before all the way up to redline. Feels like a whole different power band. You still wont' have the instant bottom end of a positive displacement blower, but it'll get to the end of the track every bit as quickly as the KB guys and is a hell of a lot cheaper than doing it all over again with a different set up.
AmBo
Active Member
If I'm in 2nd at 3000 rpms and floor it without warning you, your heart may skip a beat.
In 3rd at 3,000 it'll build quick and around 3500 you'll get that "plastered in your seat" feeling.
mostly because of the instant power i liek the KB - and the sound kicks major ass!! but yeah i knwo waht you are talkign about - smaller pulley and a tune would be great - but first i need a MAF & injectors, then icodul do a pulley and tune - already have an A2A FMIC and power pipe.
i dont go to the track that much, my stang is my DD unless it snows, so i liek the low end torque that the KB gives ya. but once the vortech spins up its awesome power
im sjtu worried about the bottom end. im ocnfident that i codul hit 400rwhp with bigger injectors/MAF and a new tune for em - and im stil at about 8psi. 11 woudlnt be too much?last time i was pricing out SC's, i dont think any roots/twin screws were carb legal. most if not all the centri kits stated CARB legal on the package/link.
then again if you live in cali, you make sure all your mods are fully reversible, cause even with carb stickers theyll still give you ****. easier to just take a day or two, revert to stock, smog, realize how much better the mods made it by driving it stock for a day, then stick everything back on.
well, im going novi 2000 that was the reason for the thread.
also, i have to buy all that other crap anyway. i already paid for my vt built stroker engine. the plan is for the blower, intercooler, cobra pumps, 60 injectors, sct maf, plugs, 8 rib pullies, and 2.9 or 3.0 blower pully. i guess i have to get a vortech race bypass too. so i am not worried about the cost of that stuff as i already have to get it. just looking at the difference in price between blowers.
i am trying to run the highest boost i can on pump gass on the compression im getting in the engine. so i am looking at boost because if im only making 10psi and 450 hp, then i have to switch pullies get a smaller one to make more boost, and make 500rwhp.
the engine should be able to handle about 15psi on pump gas.
also, i have to buy all that other crap anyway. i already paid for my vt built stroker engine. the plan is for the blower, intercooler, cobra pumps, 60 injectors, sct maf, plugs, 8 rib pullies, and 2.9 or 3.0 blower pully. i guess i have to get a vortech race bypass too. so i am not worried about the cost of that stuff as i already have to get it. just looking at the difference in price between blowers.
i am trying to run the highest boost i can on pump gass on the compression im getting in the engine. so i am looking at boost because if im only making 10psi and 450 hp, then i have to switch pullies get a smaller one to make more boost, and make 500rwhp.
the engine should be able to handle about 15psi on pump gas.
You didn't research hard enough.
.......The 1.5L, 1.7L and 2.1L kits are still 50-state legal and as far as other companies versions of Positive Displacment Roots/Twin Screw kits go, Saleen, Roush and Allen kits also all utilize 50-state C.A.R.B. approved kits to keep the smog police happy. But yeah as screwed up as things are in California, it's anyone’s guess as to whether or not they'll pass you.
Ahhh, but boost isn't a measure of airflow, it's a measure of restriction.
What's seeing 15lbs of boost on one set up doesn't necessarily mean you're moving the same amount of air as the other guy who's also seeing 15lbs of boost with his set up.That's why when I see Centrifugal and Positive Displacement guys comparing each others horsepower figures based on the amount of boost they're seeing on the gauge it makes me shake my head and laugh. Complete apples and Oranges comparison. And when I see supercharger companies trying to pawn this logic off the “more horsepower per pound of boost” sales pitch onto the general public as an argument, it certainly makes me question the rest of their data and statistical information….not just their sales practices.
High flow manifolds, big MAF and Throttle bodies and other intake mods make boost numbers go up. Exhaust mods, ported heads and certain cam grinds will make boost levels go down.....but all of these modifications are allowing a larger over all volume of air to enter and exit the engine.
Take as an example a fixed amount of air entering the intake side of an engine. One guy is running a stock 4.6L and the other has all the bolt-ons. The guy with the bolt on's is going to see less boost on the gauge, because he's removed a lot of the restriction that was backing the air up on the intake/exhaust side to start with. The guy with the stock car may see be seeing 3-4psi more on his gauge, but he's down in power 40-50rwhp over the first guy because the majority of that air being taken in is being backed up within the intake manifold as it struggles to enter the engine, or is unable to exit the exhaust side as efficiently as it should because of an exhaust system that's not expelling the spent fumes quickly enough.
…and all this of course is only taking into account over all airflow. We’re not even taking into consideration air temperature. The more you compress the air, the higher the discharge temperature. You may see a ton of boost on the gauge, but because of the elevated ACT's, you've got to add fuel and back off timing in order to keep cylinder temperatures at a controlable level. Now, not only is the guy with the more efficient combination engine seeing more airflow, but he's also seeing a lower air charge temperatures which is going to allow him to run more timing, and/or more aiflow (increased boost levels via a smaller pulley blower pulley) with the same level of octane in his fuel that you're running.
Then to throw another wrench into the mix, you get a guy with a 4.6L vs. a guy with a 5.4L spinning two identical blowers at two identical speeds with two identical engine combinations. Both guys look down at the gauge and notice that the 5.4L seems to be down on boost pressure according to the gauge, yet it's matching or besting the smaller 4.6L. The 5.4L cylinders are able to physically take in more air than the 4.6L and thus again......more power is made, with less restriction.
So….bottom line, don’t be so concerned with seeing a particular boost figure on the gauge. Be concerned with how well you’re able to move all of that incoming airflow through the engine. If you’re able to make 20-30 more horsepower than the guy next to you running the same blower with the same sized pulley, you know you’re doing the right thing.
….make your head spin yet?
no, im ok. i know what you are saying and its all good info. i dont have to have a certain boost number exactly. im just trying to push what i can on the pump gas. where ever the boost and rwhp ends up is where it ends up i guess. or i could not run the most possible boost and put less strain on the engine while still making good power, just not the most power the combo can make. we'll see.
twogts4us
15 Year Member
Pricing is on their website, www.kennebell.net. And yeah, it does leave out some components as someone noted here..plus the fact that you'd better have a built motor to sit the 2.6L on top of.
The October issue of 5.0 Mustangs and Fast Fords has a great article on the old (at that time, when they still had the 1.7L, it was the bigger blower) 2.2 on a 2V...with 20psi they easily hit 650 HP. Still not enough for ya???
The nice thing about these blowers is great power from idle. Hell, in stock form, this motor made 218 peak HP. With the blower, the dyno graph begins at 2800 RPMs and it's already at 254 HP. From there, it's a beeline, straight up.
It comes down to this...
What Would Jesus Drive?
the98stang
Active Member
blacksheep-1
Member
- Oct 21, 2006
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FWIW, I discoverred a little issue with centri's. If I hammer the gas and just tap the clutch between shifts the pressure stay up and away we go.(power shifting) If I let of the gas, even for an instant (granny shifting) between shifts, then (my theory) the bypass opens due to the abrupt vacuum increase, when I make the shift and hammer the gas the belt slips like crazy. What I suspect is happening is the the bypass operates and then the blower has to "catch up" creating the slipping as the blower tries to get up to speed with the engine rpm. It's a KB by the way.
Rickey_Bobby
New Member
What kind of vacuum do you pull @ 70mph? I'm only pulling 10... trying to figure out if it is normal, or if im about to get screwed.
DaNd4Speed
Founding Member
That's normal. I'm seeing 22 psi vacuum at idle. Most of the time even the slightest rev will drop me down to about 15 psi vacuum. I've never matched speeds vs. psi, but I'd say that 10 psi vacuum cruising around with a light foot would sound about right.
A Kenne Bell isn't a Centrifugal though, it's a Positive Displacment supercharger.
The reason belt slipage is so apparent with the Kenne Bell (and pretty much all Positive Displacment Superchargers) is because although the design of the blower allows the intake of large volumes of air in a single revolution (which is why they produce positive pressure *boost* levels at such low RPM in comparison to a Centrifugal supercharger), in order to do so it needs to utilize the use of two large, heavy screws/rotors. On top of that, you've not only got the weight of the internal components working against you, but also the resistance of the working volume of air within the unit itself. This combined with the abrupt closing of the bypass valve and/or change in belt speed basically overpowers the v-groove serpentine belt used with the accesory drive system. When switch gears under hard acceleration and you let out to switch gears, or even to a smallter extent with powershifting, the belt breaks traction with the pulley and gives you that dreaded squeek we all hate to hear.
This is why whey you get a big blower like a 2.6L Kenne Bell, or go with an ultra small pulley on one of the smaller blowers, they require the use of an 8-rib drive/driven pulley conversion to increase belt wrap on the blower pulley and thus increase traction. When you get a really big blower, you need to go one step further and go to a non slip secondary cog-drive belt system.
This can also be a problem for Centrifugal style supercdharger as well, (especially between ****s) only on a smaller scale.
blacksheep-1
Member
- Oct 21, 2006
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Gearbanger, sorry for the monster brain fart, yes I know it's a positive displacement blower, I guess I've been working long hours for two long. Anyway, my theory is essentially correct on the belt slippage apparently.
geoffsgt
Member
Damn....I didn't even catch that.
....and for all you that can't figure it out, it's "shifts" by the way.
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