let's be real for a moment

[CLABORN1960]

Okay here is what I want to know. How much realistically can I modify my vette, and still be able to have it as a daily driver with decent (something more than 10 mpg) gas mileage?

I want 400 hp at least, and as I am reading various topics here I will also need to upgrade my transmission (its an auto) and rear end...

So someone please enlighten me....

 

[mike weyman]

you can't have both.325 h.p. will eat gas like a pig, let alone 400 h.p.
you can go big or stay home.

 

[wx briefer]

Look at my sig., I am getting in the mid 20's on the highway.

 

[Edmond]

Okay here is what I want to know. How much realistically can I modify my vette, and still be able to have it as a daily driver with decent (something more than 10 mpg) gas mileage?

I want 400 hp at least, and as I am reading various topics here I will also need to upgrade my transmission (its an auto) and rear end...

So someone please enlighten me....

It's all about how you put everything together. There are guys on this forum who can get almost 20mpg, pass emissions and have the car practical for everyday driving. I'm not one of those guys but we have em' here.

If GM can engineer the Z06 to get 19mpg on the highway with 405hp and 400 ft. lbs. torque, you can definitely do it!

 

[trumperZ06]

Okay here is what I want to know. How much realistically can I modify my vette, and still be able to have it as a daily driver with decent (something more than 10 mpg) gas mileage?

I want 400 hp at least, and as I am reading various topics here I will also need to upgrade my transmission (its an auto) and rear end...

So someone please enlighten me....

I don't think you can get 400 rwhp and still have a daily driver with the LT-1. Try Rippy, Mallet, and Lingenfelter(sp?) web sites for engine info!
Now if your talking "crankshaft" hp. (~350 @ rear wheels), yeah that should be do-able!

 

[Edmond]

We need to get 69MyWay into this thread. He had a 90' that put down 378hp to the rear wheels! If he can do it with an L98, which is more of a torque monster than a hp car, you can definitely achieve 400hp with an LT1.

At the crank, you're only 100 away. Heads and cam will get you very far, along with a nice intake and exhaust system, you'll be at 400 in no time!

 

[trumperZ06]

:L Hhmmm, automatic transmissions aren't known for being...

EFFICIENT !!!

That being a fact... and wanting the car to be a "daily Driver"...

heres wishing you good luck!

 

[Hib Halverson]

There were a couple of pieces of information not given. 1) is the car to be modified the "ruby" listed as the first poster's car? 2) is that 400 at the wheels or at the flywheel.

For the sake of discusion, let's say it is the ruby with an LT1 and it's 400 at the wheels.

My guess is that a 383 short block built with all the best stuff, a set of cleaned-up LT4 heads, the LT4 "Hot Cam", LT4 intake with a big TB, some kind of low restriction exhaust and, most importantly, proper calibration and injector sizing might get you close to 400 at the wheels.

If the cal. is done right and you keep the stock axle ratio mileage might make the 20s under certain conditions.

This assumes a six-speed manual and not an automatic.

 

[Edmond]

:L Hhmmm, automatic transmissions aren't known for being...

EFFICIENT !!!

That being a fact... and wanting the car to be a "daily Driver"...

heres wishing you good luck!

Yeah, you're right. I think he should give me his car and go buy a new Z06.:L:L:L

 

[vettered91]

I don't know how much hp do I have now in my vette but it can go easy more than 160 mph with the mods I have right now with the 3.54 rear axle. Top end was last May before the mods w/o cats and just the Magnaflows with the original r/axle 2.59 = 165mph. All this at 5,200 fts altitude.

About three weeks ago I tried to see what it can do and at 158 I had to use the brakes (very easy) because the straight road ended ahead but it was still pulling hard and I'm sure it can go much more!
With 37,300 k my vette is my every day car (it's an auto) with a lot of stop & go and it gaves me 13 mpg (it's running rich)

What I'm trying to say is that I'm almost sure that if I add an ATI Procharger to the mods I have it could past the 400 hp. without too much gas drinking!

But before a supercharger the mod I want the most it's the LT4 Hot Cam Kit.

Of course I'm speculating and maybe someone here can give us a light!
just my .02

 

[CLABORN1960]

To answer Mr. Halverson's question, yes it is the 93 ruby red that I wish to modify. It is an automatic and it has 130,000 miles on it. I was thinking instead of just a regular overhaul I would go for broke and do mods that would increase the hp to 400. From what I gather it would be more difficult to reach 400 hp with an automatic and still make it a daily driver?

With engine modifications I will also have to rebuild or have built a transmission correct?

 

[Mad-Mic]

To answer Mr. Halverson's question, yes it is the 93 ruby red that I wish to modify. It is an automatic and it has 130,000 miles on it. I was thinking instead of just a regular overhaul I would go for broke and do mods that would increase the hp to 400. From what I gather it would be more difficult to reach 400 hp with an automatic and still make it a daily driver?

With engine modifications I will also have to rebuild or have built a transmission correct?

Claborn,

i am positive you could hit 400 rwhp and overall you wouldn't go for broke

heads cam combo. something other than the LT4 "Hotcam". i've seen alot of people say it's either really what they want or it wasn't enough. automatic i'd want a big lift cam. it's more effecient than a mild lift cam with a 6 speed. don't get me wrong the cam kit itself is a good kit but for an extra few dollars you can get a stronger cam and still keep it streetable.

if you plan on keeping the D36 until it breaks, keep the stock 2.59's. that fat big gear is way stronger than say 3.55's or 3.73's. (smaller ring gear).

on the tranny. alot of what i hear is 2800-3000 stalls. still very steetable. go with a trans cooler here.

dyno tune the car and find someone that can use LT-Edit and tune your car for optimization.

depending on weather low 12's easy.

atleast thats what i'm hoping this is my plan for my 12.0x-12.2x 87 Coupe L98. look below what mine is running now.

and too Trumper,

i'd run ya stop light to stop light now with the mods i got

 

[Moonunit 451]

CLABORN1960,

I've been going through the drivetrain (and more) on my 86 since around June. With a 383 stroker, AFR heads, 219 cam and a Super Ram, I don't think I'll see 400hp (?). I don't know about the mileage either (hope to find out early next month). But to a person, I've been told the D36 is at best a time bomb. D44 it is

Not bad at all to change, and now I've been through EVERY part on the exterior of this car, quite a learning experience in less than a year of ownership, and no intent to do so when I bought it:L I've sure learned a lot, but I'm still a pup compared to most here.

BTW, Mad-Mic's car is the exception rather than the rule IMHO

 

[Tuna]

I didn't do the 383 work but I did recent update my LT1 with LT4 heads and intake, the LT4 Hot Cam and 1.6 rockers. If my average MPG computer is still realiable (haven' checked it yet), I'm seeing about 2-2.5 less MPG now than before. Before, I was getting 18.5ish in town and 27-28 on the highway. Next week, the dyno will tell me what the horse power is. In the meantime, it's still a perfectly good daily driver.

I'm thinking like Hib - to get 400 and still be a daily driver, which mine is, you'll probably want to go with the 383 stroker.

 

[all4c4lt4]

I think you would have to do at least a 383 otherwise, with the stock block you would be forced to pick a different cam than, let's say the Hotcam which makes it still streetable, to something wilder where you would be sacrificing street manners.