I was just woundering if I installed the extreme performance 292 camshafts they make for the 420a how much mpg would I expect to see drop?

If your worrying about gas milage your in the wrong game son.

I am not worried about gas mileage I am just curious

Buy them and have them shipped to my house, you will notice an increase in gas mileage. All kidding aside, you have to have some type of engine management to even run these cams. You will probably notice a HUGE drop in gas mileage because of how much how big these cams are and how far up they shift the powerband.

292's... on your build? Why? Start slow kid... Are 292's even streetable?

Idk if they are but im crazy so I dont care if they are. I also wouldent ajust the rev limit cause I havent built the lower end of my block yet so I dont wanna go breaking stuff.

And whats a huge drop like 3-5mpg?

If you are buying a 292 duration cam you shouldn't be worrying about fuel economy. You are also leaving out a ton of other information. Duration is only part of the equation.

Also, its not so much the bottom end that needs to be built before winding the motor out higher its the valvetrain.. Save for some rod bolts.

Do you know if you will need to worry about P to V clearance? Will you be using adjustable gears or installing straight up?

I dont think you've thought this all the way through.

LandSpeed-DSM said:

If you are buying a 292 duration cam you shouldn't be worrying about fuel economy. You are also leaving out a ton of other information. Duration is only part of the equation.

Also, its not so much the bottom end that needs to be built before winding the motor out higher its the valvetrain.. Save for some rod bolts.

Do you know if you will need to worry about P to V clearance? Will you be using adjustable gears or installing straight up?

I dont think you've thought this all the way through.

Click to expand...

100% correct... You are talking about "you dont care about street-able" Unless this is a all track car you really need to consider street ability! It would be horrible to buy and install these cams and have to idle the car at 1200-1500 rpm with hardly any vacuum ( low idle vacuum means horrible gas mileage).. It would be even worst to have to rev up to 3500-4500 rpm to pull off from a light because you dont have any torque down low (all your power will be on the top end).. You would really hate this kind of set up on the street. If any thing go from a stock setup to a medium to mild setup. that way you can explore what works and what dosent.
Corey

I have to rev up to 4k allready cause i have no low end torque. But i also misfire...

PhilipMc said:

the extreme performance 292 camshafts they make for the 420a

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Lol, what the hell is Dougie doing? 292?

Op, don't worry yourself with these. You'll have to rev up to 4k to get these to work for you also.

Dougie, Dougie Dougie.......

MB

For the rest of the specs here is the link Xtreme Performance Camshafts - Stage 4 292/292: DSM 420A [XPS-64450N-2] - $594.99 : XTREME Fabrications, Performance Services and who is Dougie?

njdaewoo said:

100% correct... You are talking about "you dont care about street-able" Unless this is a all track car you really need to consider street ability! It would be horrible to buy and install these cams and have to idle the car at 1200-1500 rpm with hardly any vacuum ( low idle vacuum means horrible gas mileage).. It would be even worst to have to rev up to 3500-4500 rpm to pull off from a light because you dont have any torque down low (all your power will be on the top end).. You would really hate this kind of set up on the street. If any thing go from a stock setup to a medium to mild setup. that way you can explore what works and what dosent.
Corey

Click to expand...

I'm glad we agree on the meat of my post.. but streetability for me is different for you and different for him.

I have had a caged/cammed/welded center diff/twindisk + 4spd dogbox with a big open T4 turbo on it before and I DD'd that for an entire summer.

On the other end, some people think an 18G and/or some 272/272 cams on an otherwise stock setup is too laggy and unstreetable.

My point was more to warn him about the mechanical end of it..

And pulling low vacuum in and around town provides less aid in terms of braking, which I would worry about first, more than mileage at that point.

PhilipMc said:

I have to rev up to 4k allready cause i have no low end torque. But i also misfire...

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WhatchutalkingboutWillis? I can easily drive around a town without ever breaking 3000rpm, and i am sure i have sacrificed more low end than you.

Go ahead and buy them. Then after they completely fail your needs, sell them to me for half price.

PhilipMc said:

For the rest of the specs here is the link Xtreme Performance Camshafts - Stage 4 292/292: DSM 420A [XPS-64450N-2] - $594.99 : XTREME Fabrications, Performance Services and who is Dougie?

Click to expand...

He is the guy that runs that shop, has a pretty nasty 420a-t....
2G DSM 420A Idle @ 900 RPM with XPS 292 cams - YouTube
said 292/292 cams...

expect 6-8mpg drop...I guess if you're already launching at 4k around town there's not much further down you can go.

Sounds like you'll be at less than 200 miles/tank. (150-175 approx), unless you were just exaggerating. These numbers arent scientific by the way and just represents what I would guess from my experience...

His other thread states that he has an automatic...

95TalonOwner said:

His other thread states that he has an automatic...

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WOW. What will he need for a converter to even be able to get going?


Oh, and your valvesprings will probably coilbind with that much lift. You will lose power EVERYWHERE with these cams. Your compression will be really low, and your brakes will suck whenever you push the clutch in due to no vacuum.

95TalonOwner said:

His other thread states that he has an automatic...

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Looks like a stick to me.

If I upgraded my valvesprings would I still lose compression?

I'm just asking because I'm curious. Where are you going with this? (or think you're going?)

johnovision27 said:

I'm just asking because I'm curious. Where are you going with this? (or think you're going?)

Click to expand...

But that doesnt answer my question

Your question makes no since. Valve springs have nothing to do with compression. The overlap from the cam is what makes you lose some of your compression. You need aftermarket valve springs to even run this cam so its not an IF you want then or have to have them. Its a you NEED these in order to run these type of cam. This cam is whats known as a "no bullshit" cam. Its not designed be be anything other than a race cam on a 2.0. Like stated before "streetable" is all in the eye of the beholder, what some consider streetable others would not. I still think for you mod list you should spend your money elsewhere first.

EDIT: And with your current mods I think you would probably loose power by getting these. I know that some of the Neon guys running big cams even have problems with cams like Crane 18's melting their valves because of the overlap of the bigger cams, I for one wouldn't risk it so IMO to even run these cams on a stock bottom end(which is stupid imo) you would need a bare minimum of SS valves, upgraded valve springs, and adjustable cam gears so you can degree in the cam and a manual IAC if you don't have MS.

So how much compression would I lose with this cam?