My father in law bought a 85 vette
its dog slow
what are some mods we can do to make it faster



thanx for the help!!!

 

I would like to start with:

How slow is "Dog Slow"? An 85' vette should be able to do 0-60MPH in about 6 seconds, so if that is "Dog Slow" then you will want to begin with a modification strategy. If the car feels slower than that, then a good tune up should be your first priority to get the car back to it's original performance level.

 

its not that slow but not 0-60 in 6 secs it feels like that 230 hp

i am more used to 300-350 horse
like my buddys vette has

 

LSx, or even LTx swap. That'll get you there.

 

Swapping in an ltx is not nearly as easy as building up a miniram motor.

As far as lsx goes, not for the faint of heart or people with a small wallet.

 

1.6 roller rockers, intake, exhaust, heads, cam, more cubes, nitrous, blower...

How much money does he have to spend on the motor? (And, will he be paying for labor?)
What are the contstraints with regard to emmissions?
How much HP is enough?

 

i would like to see 300-350

and we would do the labor if its easy enough

we would like to do it as cheap as possible

chip does 20-25 hp right?

 

Ummm, no. I suggest you take a look at vader's website.
http://temp.corvetteforum.net/c4/vader86/

 

I had a pcmforless tune. I got a DYNO proven result(from a different dyno testing center) and with/without the chip, the end result was the chip gave me 14 hp on a MILDY modded car. The car dynod at 218 RWHP. Id assume that is roughly 250 hp crank.

Upgraded exaust minus headers, ported/polished stock heads, cold air intake, pcmforless chip, no emissions, flowmasters.

The only way a chip would give you 20-25 hp is on a heavily modded large cubed motor that is running on a stock tune.

 

The mods that showed the most improvement in my Vette were a 2600 torque converter & 3:73 gears from Pete Kane. Thanks Pete. They weren't that expensive either.

 

An 85 Vette isn't slow, 5.7 to 6.0 ,0-60. If you feel it is a slow then check the condition of the engine, maybe do a good tune-up. If you still need more power, there are two ways to get it. Build up the engine for more power or free up the power in the engine..ok, 3, replace the engine with a more powerful one. You can always change to AFR heads and maybe a cam swap.
Here is a site I stole from the C-3 forum;
http://www.ssmoparmuscle.com/speedco...&OORDERDIR=ASC

 

Change the air filter to a K&N, cut the air lid, defin the MAF, put on some good 180 CC heads, put in a roller cam with .525 lift and 218/224 duration on a 114, long tubes, high flow cats for 240 RWHP.

After that it won't be fast enough so then do a 383, 200 cc heads, .575 cam on a 230/236, HSR, larger TB, full 2.5" dual exhaust for 380 RWHP.

After that it won't be enough so do a 406 with an STS turbo.

After that it...

 

everything i have read is the power is cut way down due to the smog stuff

is there a way to free up that power loss?

so where would you start exhaust with long tube headers

evaluate and go from there

 

I yanked off my EGR and plugged it up with TPIS block off plates. I am about to buy a TPIS air delete pully. I removed all air tubes/plumbing and AIR computer. I also removed all cats and put on a true dual exaust(no X or H pipe) into 2.5 3 inch tip flowmaster 40 series. Next will be longtube headers with no EGR or AIR holes in it. That will remove all aspects of smog. I also had my chip have the EGR and AIR codes removed from it. No more smog. period. Street legal? Not a chance. Do I drive it on the street? You betcha it's a daily driver. Port runners, base, and plenum, power coupler, SLP cold air intake, BMAD, cam, heads, headers, roller rockers, lt4 springs,....Then you can bore/stroke it, supercharge, turbo, nitrous, Big block motors, crate motors, the options are endless......

Edit: Shift kit, torrque converter, aftermarket clutches, short throw shifters, differential gears, better cooling systems, lower thermostats, underdrive pullys, proper maintenance/tune up,

 

do yourself a favor, buy a set of vortec heads and a Scroggin Dickey TPI manifold for vortec heads, and enjoy the extra power on regular gas. It should get you right up to 295 horse, 360 on the torque.... If you want to get down and dirty, change the cam. But you will wish you didn't after all the work it takes to get that cam in there.

BTW, egr helps your engine not detonate with cheap gas and advanced timing.

 

Calculate the money all of these mods will cost to get you 300-350 hp. Save that money. Sell the '85 and buy an LT4 and you're done

 

Are you talking about the fastburn aluminum heads??
Dave

 

 

I'm confused!

You say that it FEELS slow and that you are used to 300 HP. Typically an engine of the same size that has 300 to 350HP is indeed much faster but often FEELS slower than the low RPM torque monster that is the L98. Additionally the amount of Horsepower is only part of the performance equation. Weight and aerodynamics are just as important. Put 350HP in a heavy, wind pushing truck and it will make the L98 Vette feel like a Rocket Ship by comparison.

Torque is what you feel and what makes the car fun to drive. Horsepower is a calculated number and wins races. Horsepower also makes the marketing people happier when they can post high Horsepower figures.

The L98 engine was not long on Horsepower but it had great low speed torque. It's lack of Horsepower had almost nothing to do with emissions equipment. The engines of the seventies DID suffer because of the way that emissions were dealt with. The lack of L98Horsepower was greatly effected by the TPI system. It was designed for a 305 during the period when GM was saying that the 350 was dead. Once they came back to their senses and brought back the 350, the 305 designed TPI was all they had.

As others have indicated, if the car FEELS slow, then there is something wrong with it.

 

I apologize for being a little bit of a smart a$$, in previous posts. Actually someone commented earlier. The quickest way get the SOP feeling is rear end gears. Free up the exhaust a little bit, and get some airflow in. Start there, then look at a cam, roller rocker package. Get the chip burned after the cam and you'll like the car alot more.
Then down the road you might look at a stroker package, or even just a head porting and aftermarket intake.

Take your time, and think about what "power" means to you. Top end, low end? Are you going to drag race, auto-x, or are you looking for driveable streeter with some stop light "umph"? Figure this out and build accordingly. Everyone here has some pretty good insight.