As per our conversation Andy...

In the spring (If I make it that long with the ZR1 fever coming on strong) I will be looking to make a few modifications to my boat. I actually happen to really love the style of this car, and it is as you can imagine one of the most comfortable cars on the planet. Unfortunately it is slow by Corvette standards (I have been spoiled by my C4 and now the C6) and I would like to do some "light" mods to improve its drivability.

In 1997 my mother owned a 96 Callaway Impala SS (see how many of those were made!). I have vivid memories riding around in that car, and since then it has been a fixation of mine. The other fixations were the 71 Chevelle, A Corvette, and above all, the 57 Chevy. My moms impala was amazing from what i remember. Callaway built a great car. It was fast 409Hp, it sounded great, and it was a pleasure to drive. It retained all the drivability you would want out of a luxury sedan, but was an animal when the pedal hit the floor.

So now that you see where i am headed with this. This is the vehicle I am attempting to duplicate, of course on a much tighter budget, and without opting for the 383 hers had.

Mine is comfortable, and in excellent condition, but its a dog as far as performance, and since my recent mods it has lost alot of its driving pleasure.

The only mods so far: K&N air Intake with smooth elbow, 3.42 Rear with Eaton #400 Posi, 3000 Edge Converter, Transgo Moderate shift kit (which clunks from gear to gear), Goodyear Eagle F1 GS-D3's 275/40/17, Borla Cat Back Exhaust, and a Brian Herter Tune.

In the spring I will be looking to improve upon any mistakes I may have made, and also do a Heads Package, and a cam, and a set of headers. I would ideally like 400HP, but not at the cost of daily drivability. I don't care all that much about gas mileage as long as I am getting at least 15MPG Highway. Car weighs about 4500lbs with me in it.

The consensus seems to be I should be able to squeeze 400 Streetable, tame ponys out of this car and still get 24MPG... according to some memebers.
Ok, So,.. whats the plan?

DG
[IMG]http://i142.photobucket.com/albums/r97/BG528/Impala027.jpg[/IMG]

Quote:

Sounds like you already have it???

Keep us posted. I love those impalas.

Matthew

Wheres Bogus??

sleeping, damnit.

I will defer the transmission issues to Pete. I am not a huge fan of the high stall on a heavy car, tho...

The Eaton is a good part... I would leave it. If it was mine, I would go down to a 3.2x gear, tho. It will make it much more streetable.

Your Mom had a Callaway Impala? Damn. Mom's cool.

If I remember rightly, their stock EPA was 24mph highway. So getting performance and getting that are mutually exclusive. Weight is the killer here... but lowering the rear gear will get you closer.

This is where a softer gear and more power will result in a nice compromise.

If it was me, I would build a moderate 383. Get a short block from another Impala, Caprice or Fbody and go to town. The charm is that you can take your time and ammortize the cost out over a longer time frame and not harm your car as a daily driver until the motor is ready.

Extra power will really help keep the refinement. I reference the Callaway as your benchmark.

What does everyone else think?

I'm with Bogus, build a mild 383. Small cam. Get some alum heads and dump the cast iron crap. Every pound helps.

Ditch the high stall. No need for it IMHO. Stay with the 3:42 gears you got. Nothing wrong there.

I would toy with the idea of a 6 speed swap. I would do it just for the fun of it and the challenge. It's been done before. Not sure what year you have, if you have the column shift or the console shift.

I've wanted a Imp SS as well, but every time I see one, they are mostly ragged out.

I've got to go with the stroker idea too, reason being is the torque benefit which becomes even more important with a heavy vehicle. You can buy econo stroker kits damn cheap these days. It doesn't have to be an all forged set-up for your purposes. The difference in torque between a 350/400 HP engine and the same HP level with a 383 is substantial, very substantial.

I read through the comments. I agree with losing the high stall converter. I noticed that the lighter cars take higher stall well but a car that is 4500lbs is a pain with a converter that high.

Whats interesting is that I see alot of people on the ImpalaSSForum running the yank 3600SS converter. Thats a 3600 stall; and no complaints. I don't get it.

I do however like the slight improvement over the stock 12in 1800 stall converter, so rather than swapping it, I think I will just have my 9.5in re-stalled at 2400, and tightened up.

I have no complaints about the gears, except for the fact that on decel from 40-30MPH you can hear a noise; sounds like tires slowing down quickly on cement/concrete. But most people who have seen the pattern say it is almost dead on so I am not too sure what to do about that.

My next mod, which will be coming within the month will be a new aluminum driveshaft from Denny's. I've got the dreaded vibes.

I am confident I could probably build a motor myself, with a little bit of refreshing in certain areas. My origional plan was to go with a moderate Llyod Elliot port on a set of Aluminum vette heads, and a cam... and call it a day. I figured I could squeeze 350 Wheel HP out of that and still retain most drivability.

Does anyone on here have any experience with Transgo... I have a couple of questions???

DG

[IMG]http://i142.photobucket.com/albums/r97/BG528/Gears005.jpg[/IMG]
[IMG]http://i142.photobucket.com/albums/r97/BG528/Gears006.jpg[/IMG]
[IMG]http://i142.photobucket.com/albums/r97/BG528/Gears010.jpg[/IMG]

Ironically the stock cast iron heads outflow the aluminium ones.

I'd put a blower on it, go figure, plenty of room for it and an intercooler.

Yea but as far as I know, The aluminum ones outperform the stock ones after porting. I haven't really spent much time on this yet, I just had an idea of what I wanted to do.

Craigslist right now has a whole LT1 Powerdyne setup for the LT1 Impala. $1000 OBO.

DG

Anyone want to take a crack at the gears?

DG

Quote:

Everything looks good. The meshing is right in the center of the tooth, it looks like you could shim the pinion shim thickness and bring the mark a little further down the tooth.

But yet everything is still within the tolerances... the pattern looks "acceptable" if not perfect, and I have a noise on decel from 40-30. The rest of the time, the rear doesn't even make a peep. I am hoping in time it will "break in" and quite down. But i know from my little experience with rears, that they don't need break in time to quite down; infact they usually get louder.

DG

I assume the diff housing is square? The GM rear is weak at best. I am a big fan of the S60 from Strange. I am sure it's not cheap, but it is a stout piece.

A $1000 blower? Damn. Even if you have to spend $2k to make it right you are way ahead of the game.

Hi Dan,

Regarding the diff noise....had that exact same problem once. Found out that the carrier bearings were actually making the sound due to the pumpkin caps were 'oversize'. (It was on a Jeep GC and they're aluminum...had stretched) I fixed the problem by machining down the caps and re-installing. Hope it's as simple as that in your case.

Re the best bang for the buck on power....I (wanted to say) would go for torque over HP, thus the 383 stroker. Kits ARE really cheap. Although this forced induction idea sounds much better! I mean, no pulling the entire motor and rebuilding it? That labor ALONE is worth a Grand (even if you pay yourself $3.00/hr!)

Calm,

Thanks for the tips... I will have to spend sometime looking into that.

DG

Definitely piece together a stroker over time or forced induction. With the weight I think youll be dissapointed in ported heads/cam for the work and money factor. If you do dont go too big on the port job

Does anybody know of any reasonably priced stroker sets. I'm not quite ready to jump into this yet, but I wouldn't mind formulating some ideas. Wheres the go to place?

I know I've seen "kits" avaiable. I don't need any crazy sh*t, the most HP the engine will see is 400-450HP. I just need a little more punch, not really looking for a monster. I could probably even do hyper's instead of forged and that would be just fine.

DG

cnc-motorsports

This place was very reasonable back when I bought my rotating parts. I didn't use a kit but they still made me a kit price once I'd selected my parts.
But always shop around, things change.

Wow, their budget setups are really cheap...

The forged stuff is a little more expensive but still not that bad at all. I am going to have to investigate further.

Thanks Notorious,

DG