Well, as you all know, I'm prepping for a stoker conversion. My absolute number one concern is driveability . Unlike the majority of the forum, I would be willing to sacrifice some HP for driveability. I know that driveability generally equates to: the cam, intake and gears you choose based upon the rpm range you plan on running. That being so, am I better off to go mild (lower flow #'s) when choosing an intake? What do you suggest I use for an intake?
Thanks for the input. :cheers:

 

The intake you already have. With the LT4 that is your only choice. I also like the heads that More Performance uses. They are done by CNC Heads and More sets them up with Comp hardware. Mike will also pick a nice cam for you for driveability and emission concerns. His website is http://www.moreperformanceinc.com
I have a 396 motor with the Super Ram. I had driveabilty issues with the Miniram and the Superram drives like a champ. I need more cylinder head, more porting of the intake and bigger cam to get my targeted HP (375 RW). Maybe next year.




[Modified by 89vette, 7:27 PM 1/31/2002]

 

If you are talking about the airbox, for every day driving, use an open air lid. You can cut yours or buy one from Ecklers, Mid America etc. I have not heard big gains from the the SLP claw. Some report good gains by cutting holes in the shroud below the K&N Filters using the SLP claw. The Vortex unit and other styles that flip the air intake I'm scared of sucking up water and hydra locking the motor, but I've never heard of it happening to a Corvette.

Who are you planning on having build the stroker?

 

Sorry, meant heads, not "intake". Been a looong day. :yesnod:

I was talking about flow rates for the cylinder heads. For instance, MORE performance has Stages I, II, and III port jobs. I'm wondering if the driveability would be increased by going with say their stage I, or II heads instead of the stage III's they generally use.

 

How are ya Lamar? That's a good question. Lingenfelter has sent me their contract packet, so things are getting serious. I've been sold on their work for a long time, but now that it's come to writing the check for the 50% down payment ($6500), I'm taking a last look around, and MORE is once again on the list. I want the best possible setup for a bulletproof daily driver.

How are you coming along with selling your car? I haven't seen it advertised on the forum?

 

hehe oops :) http://www.fierolt1.com/lt1_lt4_headflow.htm has some flow #s

I would talk to ChrisB of Speed Demon Motorsports and get some Gallant heads stage 2 or 3. I think the LT4s come with 2.02/1.585 valves and I would spring for titanium retainers. MORE's package is very good as well.

 

A stroker can absolutely give you better drivability - more torque and horsepower across the powerband, and the potential for an even smoother idle.

I wouldn't look for low flow numbers, I would make sure the heads were ported with your goals in mind. As long as your charge velocity is kept up more flow will give you better drivability. Your number on factor really is going to be camshaft choice.

 

Like I said before, call ChrisB or ChrisK of Speed Demon. Even if you don't do business with them, you'll learn a lot.

Charles

 

You can't go wrong with MORE doing the motor. I've talked to some very happy customers including my old roommate's father who had 383 LT4.

As for my car I'm waiting on some #'s to come out on the idea talked about at Jeff's shop. We'll see I'm not in a big hurry now.



[Modified by 93Polo, 4:12 AM 2/1/2002]

 

Your cam will be the largest factor on driveability. Choose wisely.

 

For driveability , the cam will be your more important concern.

Vic

 

I would suggest having Speed Demon Motorsports help you pick a cam. I have a pretty mild 383 because I was really worried about passing emissions here in Colorado. I had them help me and they came up with a GTP 2 Cam, 216-226/508-534/114lsa - with this cam I passed emissions even better than the car did completely stock yet I have decent HP and excellent driveability.

Tim

 

Three letters will guarantee your car drives AS IT IS NOW but with TONS MORE POWER.

L P E

 

The GTP cams do work well. Some local Z28s have run their cams. Also MORE has used a Crane 222/230 grind that works very well. I believe that is the cam my friend ran in the MORE 383 LT4 I've talked about. The Comp Cams 305 cam is a very good and drivable cam too.

A local friend from the f-body club built a 355 using the Crane cam it is a very driveable combination. http://www.mindspring.com/~threed/ has info on his combination with chassis dynos.

 

i have a mild 383 stroke and its very drivable. I also live about 30 min from LPE
i have seen there work.very nice stuff. I think there kinda high but hey i bet it doesnt break. my 2 cents. jay. hey JD I saw ur car on there site to have you sold it yet ??

 

A couple of guys have hit on this already. It's the camshaft.

The MAIN factor which determines the overall characteristics of an engine and, hence, driveability, is the camshaft.

Camshaft selection has by far the greatest effect on overall engine performance and characteristics, idle smoothness, part throttle response, fuel mileage, etc., than any other component.

Stay at 210 or below at .050 tappet lift and keep the LSA wide for a smoother idle and broader power range. Something on the order of 114 to 115 lobe centers. Also, choose a cam that has an exhaust duration no more than 6 degrees greater than intake duration, both @ .050. Even tighter than that would be better; like a 210/214 or 212 across.

Stock cams are in the 204 duration range @ .050.

When you get up into the 218 or 222 range, you've crossed over into a performance oriented cam territory.

In choosing a shorter duration cam, you've got to keep an eye on compression too, since short duration cams build a lot of cylinder pressure early. This can lead to detonation when you crank in too much compression. With a short cam, I'd shoot for 9.5:1 CR max.

Think of cams in 6 degree steps. Each 6 degree difference between cams represents one step difference in cams.

When considerating of flow, air flow velocity is key to throttle response. If deciding between, say, two sets of cylinder heads, if both sets flow about the same, choose the set with the smallest intake port volume. Concentrate your attention on low and mid lift flow numbers for you comparison, NOT max flow numbers. Exhausts should flow about 75% of the intake too at each lift point in order to have a good flow balance.

Just my thoughts.

Jake

 

I had the CC305 cam in my 396 and it was very tame IMO. If I remember correctly it is a 220/230, .540/.540, on a 114. I don't think I would go much smaller than a Hotcam in a 383/396 combination.

 

uh huh :yesnod: :yesnod: but for some major $$$$$

BTW, i'm stickin' with the HOT cam .. so far it seems excellent to me for my 383. Just perfect for daily driving (of course I'm still doing some tuning on it .. trying to smooth the idle a bit)


[Modified by Glock'94, 4:09 PM 2/1/2002]

 

On a stock motor with catalytic conveters a hotcam on a 350" bottom end generally has no problem passing. Don't forget that we are talking about a 383/396" engine here which will definitely change your cam selection range - the extra cubic inches will make the same size camshaft idle much better.



What do you mean by performance cam? If you mean make more power than stock I would agree, but if you mean idles badly, can't pass emissions, etc. I would have to disagree with that point.



Excellent point, and the converse is also true - if you go with larger duration you can go with a little more compression and regain a bit of low end power/drivability (comparatively). I do think your 9.5:1 comp. number is geared for Iron heads though. Stock compression is going to be from 10.4:1-10.8:1 (lt1/lt4), and any of these cams are larger than stock. Compression is almost always a good thing as long as you aren't detonating/pinging, and the minimum I would go with would probably be 10.8:1-11:1, and generally like to see closer to 11.5:1 (depending on the setup of course)

 

This demonstrates the main problem in responding to a question such as this one. So much of it is subjective.

An engine which has excellent driveability to one person may not meet the expectations to another.

My advice is admittedly subjective too. I'm running a 415 CID, modded TPI with a ZZ9 that has 212/224 and from my prospective, drivability is marginal; barely acceptable to me.

Even with 11.0:1 CR, reprogrammed PROM, 26# injectors and smallish port aluminum aftermarket heads and headers, idle hits noticably. I can only imagine what a 218 or 224 cam would be like.

Younger guys and even some ladies love the sound of my engine, but I'm years beyond appreciatlng the 'rock'.

I've changed more cams in my lifetime that you can shake a stick at and I now know that whenever you increase duration in the area of 20 degrees more than stock, even with more cubes, driveability suffers.

Camshaft selection is always a trade-off; you give up something to gain something.

Whether it causes the engine to cross the acceptable threshold into the unacceptable arena is a personal call. For me, anything greater in duration than what I'm now running would be completely unacceptable FOR ME.

As I said before, just my thoughts. Your mileage may vary.

Jake