i recently put my 84 to the test on 1/4 mile and to my surprise top speed was a wopping 85mph what a shame this is a all stock . (no mods.) i was all most beat by a fordf250 diesel it ran 83mph. what should an 84 with auto. trans. run any help would be greatfull.(thinking trans. is not shifting like it should) :mad :nopity mabe i should just hang my head in shame

 

I hate to say it man, but that may be the way it goes for your engine. I have an '87 and it's obvious that engine technology has improved greatly over the last 20 years and cars have gotten lighter. As much as I hate ricers, I have to admit they're putting out 230 horse and 7 second 0-60's with a stock 6 cylinder, which is frightenly close to what our models were putting out stock. Anyway, to answer your question, that sounds about right for your car. An auto with a 2.59 rear (i'm guessing) and Crossfire injection may very well turn those numbers after 20 years of fatigue. Maybe it's time to tinker under the hood? Don't be ashamed - after all, you have a Corvette! :hurray:

 

http://corvetteactioncenter.com/specs/1984/84perf.html :steering:

 

:cool: site Thanks for posting!!! :cheers:

 

You're doing better than the 1982 Crossfires. Last weekend at Vintage Thunder I got lined up against an 82 with a tired engine. I think he had reached the 1/8th when I reached the 1/4. He says he is about to rebuild his.

These engines have come a long way from the depths of the 70s.

 

Time to break open the wallet...

 

I felt bad posting a 14.1 @ 100mph on my best run...with 125K on it.

 

Don't be ashamed. The 84 was a revolution when it came out. And the Z-51 is still probably the best race suspension Chevy ever put out on a road car.
The Xfire was a compromised motor. With a little work, you can be running low 15's and high 14's. Its got tons of torque and responds to mods just like any other SBC.See my sig. Go to http://www.crossfire.webhop.net to open your eyes a bit to the possibilities. Good place to start. :chevy


[Modified by Dominic Sorresso, 6:38 PM 6/20/2003]

 

:iagree: ...........open wide............ :D

 

Yep....mine runs out of steam around 4500 rpm's.....I've got alot of mods done...but at least its a good driver.....
If you need more info on your crossfire...go to the crossfire forum http://www.crossfire.webhop.net
Lots of great info on your crossfire.......
Good Luck...
tony
:thumbs: :thumbs: :thumbs:

 

That sounds about right. My '84 ran 16.75, the first year out. Even factored to sea level, that's only 15.80's. So far my best is 14.72, a full two second improvement, last August and two weeks ago. I have few mods, the engine is untouched and worn out. Mostly done through tuning and foolin' with it. I have WAAAY less than $1000.00 invested in improvements. Good luck and...

RACE ON!!!
1984 Crossfire
Member NHRA

 

What have you done to yours? I mean it doesnt feel like a 15sec car, Feels like a 13 sec car when I take off from a stop or a 10mph roll.

You know how they say, 100HP more = 1 sec improvement, Is that true for 84's also? B/c 300HP should be lower then a 14sec 1/4 mile. :confused:

 

It feels like a 13 second car at low speeds, because it makes quite a bit of low end torque. That, coupled with 26" tires, a 3.08:1 rear end, and a 3.06:1 (automatic) first gear ratio, makes it jump. The low performance cam, heads, and really restricive intake manifold, kills the ability for the L83 engine to make any horsepower. Horsepower equals torque times rpms divided by 5252. For the above reasons, the Crossfire doesn't make enough torque above 4000 rpms to develope any great HP numbers. That's why you shift at or about 4500 rpms...the engine is DONE, above that. Underneath that widely mis-understood, mystery manifold is a normal medium performance small block Chevy engine.
Are you saying I've added 200 HP to my engine? No way! That sucker only had 205 (rated), when I started playing with it, and it has never been opened up. The heads have never been off, it has the factory installed cam and timing sprockets/chain. It has over 150,000 miles on it, including 6-700 quarter miles passes. It burns a quart of oil every 200-300 miles. It's worn out. If it still has the factory 205 HP, it's a miracle. The replacement IS on the engine stand, though. Then watch out. Thirteens, for sure at THIS altitude. Good luck, and...

RACE ON!!!
1984 Crossfire
Member NHRA

 

Wow....I can't believe that. But.....maybe I can...84 was the first year into the C4, prior to the C4, the Vettes were real dogs. No power. L82s and L48s only had about 190 to 210 Hp if that. They really were not very good performers. I had a 79 L48 4 speed that ran well only after I rebuilt the Carb and changed the Camshaft, Lifters, Pushrods, and Exhaust system. My daughter has a 78 L82 Silver Anniversary (It's a dog too). I have a 96 Collector Edition with a 330Hp Lt4 6 SPeed This is NO slouch..it runs like crazy! How many miles are on your 84??? :confused:

 

Well I have 230K, runs pretty strong. :yesnod:

 

Light84,

When you run 13's it won't feel like 13's. Last October I ran a 13.6@100mph. Didn't feel like it. Lost to a GS by .07. That's stock tires, rear axle, and emissions. The Xfire can make good times because of the low end torque. It can also make crap times because of the low end torque. Can't come out of the hole at anything higher than 12-1300rpm. That's what makes it so much fun for the street. I actually had a higher speed and quicker time thru the 1/8 than the GS. Top end is where I lost out. My last dyno showed a torque peak of 347rwtq@3800rpm and an hp peak of 275rwhp@4800rpm. In fact, rwtq is never below 300 from 2500rpm to 5000rpm. I think I should be able to improve on those numbers with WOT fuel tuning and bumping up the WOT TSA(total spark advance). At the track and dyno, I was running 28d total. What's important is to plan your modifications so that you "optimize" the strengths of the motor you have. Don't try to make the Xfire something it isn't. Its a torque monster and that can be a lot of fun. If that's not your bag, use some other induction system. :thumbs:

 

HOLY SHI1, 347rwtq@3800rpm and an hp peak of 275rwhp@4800rpm. Damn, how did you get that much power out of your CF?? :confused: :confused: DId you change out the heads, and an offy? Maybe add a new cam and a high flow exhaust? :confused: I'm planing on, not for sure if I can get it done, but Im thinking of fabricating up a Twin Turbo setup. This will have to get me some crazzy TQ figures and maybe 300Hp at the fly. Add that to the list of mods that you have, run the Turbo system at 8-9psi, thats about 520rwtq and maybe 400rwhp. :crazy:

 

Welcome 2 the :party:

Don't feel bad, if you really wanna learn how to improve the numbers, ur at the right place............

Hang in there bro.............

:cheers:

 

Don't feel bad. My 85 runs like a raped ape off the line, and builds steady speed up to about 90, and then kind of takes it's sweet time building any more, but it will....slowly. When I romp on it from like 70MPH, it feels like I'm driving my wife's V6 Grand Am. :lol: But hey! I don't race the thing, so nobody has to know that it's not exactly a powerhouse. I guess the stock L83 and the L98 would do ok in a light to light challenge because of the ungodly low end torque, but if a guy has deep enough pockets, the possibilities are limitless on what he can do with these old motors....... :auto:

 

Thats about what an 84 runs.
There are some thing you can do. Loose some weight, and start modding.
Do the little things.

This is the most telling figure i saw off that site.
I'll try to put that into perspective. (im trying to remember the numbers I saw)
The L98 does 100 in about 14.1 seconds.
The LT1 does it in 12.6s.
The Lt4 does it in 11s
The LS1 does it in 11s
The Ls6 does it in about 9.6s. :eek:


Start modding that Crossfire!!!
BTW: it handles great, and is a great Auto X car.


[Modified by Marty McFly, 11:46 PM 6/22/2003]