CBX

I have a 97 C5. I plan to install new heads (AFR 205's or the new Darts) G5X3 (or similar) cam, timing chain, and oil pump this month. I have Dynatech long tubes and a twin cone intake. I have 2.73 gears and a stock TC.
In you opinion, how well will it perform on the street with the 2.73's? What kind of 1/4 mile times can I expect?

Should I just go with the 3.42's and a 3200 stall? and if so do you think that will affect my cam selection? Thanks in advance for any advice.

Patrick G

iTrader: (14)

Your car will be an absolute TURD with the stock converter and that big cam, regardless of how much gear you run. You have to understand, you're going to need a looser converter just to help out with your idle situation. See a G5X3 is going to want a 900 rpm idle. With the stock converter, any speed over 700 rpm is going to pull against the brakes. Can you imagine how hard it's going to be pulling on the brakes at 900 rpm?

Then there's the performance aspect. With 2.73 gears, you're going to be going 50 mph before the cam really starts making power. Most cars with stock cams will be 3 car lengths in front of you by the time you start making power.

You can keep the 2.73 gears (which I'm a big fan of BTW) if you get a good high stall torque converter. Don't go cheap here and don't get one that stalls too low. Ideally, you'll want a 4000+ rpm converter like a Yank SS 4000. If that sounds like too much, it's really not, but if you must go lower, I'd say you'll need to consider a different cam if you go below a 3500 stall.

Your choice of engine parts sounds good. Get your driveline up to par and you will fly!

CBX

Thanks for the reply. Do you think the 2.73's with a high stall is the better way to go? Also, I thought the stock TC kicks in at around 1600.

Patrick G

iTrader: (14)

With a high stall converter, more gear is not as necessary. You'll get great gas mileage with 2.73s and your tranny will last longer because it will be rare that you do many 2-3 shifts at WOT. Do I think it's the better way to go? Not necessarily. More gear and more converter is typically better, but the converter is really the key component here.

Yes, the stock converter stalls around 1600, but the G5X-3 doesn't make good power until above 4000 rpm. That climb from 1600-4000 rpm is slow and painful with 2.73 gears and stock converter.

CBX

Maybe I should go with less cam? I wasn't planning on spending the money for the TC and differential right now. But I also don't want to look back later, or do the work twice. I also spoke to Ed Curtis and filled out his questionnaire. He is working on a package for me. I will be curious to see what he comes up with.

CBX

BTW Patrick, those are some impressive numbers on your car.

foff667

iTrader: (2)

i totally agree with patrick and just to add to what he said I have first hand experience with this HORRIBLE combination of heads/big cam/3500 stall/2.73 gears alot of bucking in 4th gear unless you work on it with a tune...i was tuned by a "pro" and still had a ton of it...wasnt until i set the converter to unlock right at the point where i was having issue that i was happy with it.

CBX

Thanks, I would rather ask the questions and do the research now than pay for it later. I figured I would get some good responses from this site.

calongo_SS

iTrader: (7)

If you can't afford to do all of it now, eliminate the cam, heads, or gears. The converter is the absolute first thing you should do in your situation. I'm running 3.73's, 4000 stall and a big cam. It's a pretty good combo, not very easy on tires, but a lot of fun to drive.
I'd also like to add, that I was running a 3500 stall with a smaller cam than the g5x3, and it wasn't enough verter. I'd consider running a considerably smaller cam, or more converter. The 2.73's will be ok, not ideal, but not horrible. Also keep in mind that a high stall will feel pretty sloppy around town with 2.73's. But that is something that may or may not bother you. The gears will give a performance increase, and help with drivability. They'll help tighten up the stall, and keep the r's up a little more to help with any bucking problems.

CBX

It's not a question of can I afford it. I can, I just have other projects going on right now. I didn't want to tie the car up right now for any legnth of time so I can still drive it before winter. I guess I could put it off til winter then take my time. I can do the heads/cam myself, but I would prefer to pay to have the TC and gears installed. Too much hassle without a lift.

calongo_SS

iTrader: (7)

I'm starting to agree with you on the hassle part. I've done 2 converters now on jack stands. It's not a whole lot of fun. If you can't get the verter done with the heads/cam, I'd wait.

CBX

I think your'e right. I guess I could have the T/C and gears installed first, do the heads/cam myself, then have the car properly tuned. I was told that I will get the best results by having the right combination of all these parts. They should be designed as a package of components, not just added. Also, I will only have to tie the car up one time and do it right.

CBX

Any ideas on what it should cost for a new converter and gears installed?

foff667

iTrader: (2)

i had my converter installed for $175...gears usually runs $250-350 for installation. Definitly try and match your converter to the cam you get...as stated my 3500 stall was way too small for teh cam i ended up with tsp231/237 so keep that in mind once your ready to plop down that $

Ragtop 99

iTrader: (7)

Keep the 2.73s, get a 3500 stall and get a cam with more midrange power and less top end focus. The GX3 needs to spin pretty high for full advantage. Reduce the duration and tighten the LSA and you'll make good power in the rpm range that will work with those gears and a 3500 stall.

CBX

If I go with say a 230/236 112+2 LSA, with aftermarket heads and a 3500 stall (or more). Will this be a good match for 3.42's or 3.73's? Also won't it affect my tune if I add the gears later?

Patrick G

iTrader: (14)

That's still a pretty good size cam, but more in the daily driving, street/strip range. 3.42 gears would be very nice with a 3500+ stall. You'll need to re-tune for gears in the future because your shift points and converter locking speeds will be completely different. You need to save up for 2 tunes if you don't do everything at once. Maybe that will give you some motivation to buy your own tuning software.

Tuning your car with a laptop is more fun than turning wrenches! You see big gains and don't get dirty.

CBX

I am thinking about it. I have already been looking at LS1 edit and EFI live. (I wanted to go with HP tuners, but it doesn't work with my car, I had HP check my VIN). I have been lurking in the tuning threads and looking at demos of these software packages and it seems like a fairly involved situation. Seems like a long learning curve just to get going. Although it would be nice to be able to change and experiment. Anyways if I don't decide to try my hand at tuning, I will just bite the bullet and do it all at once, I can't see throwing another $500.00 away.