Ive asked a million people and they all have there own opinion. So Im gonna ask the guys that have em

When going 20-30Mph in a IROC-Z Automatic, If you move it from D to 1, should it shift down or not?

People say "yea the car u were gonna buy has a dieing tranny"

Other people say nah It shouldnt...IM SO CONFUSED!

 

depends on the gear, but most with 3.23 or deeper gear won't from the factory. the governer is meant to overide it. changing the 1-2 downshift valve (included in most shift kits) will fix that. some of the earlier 700r4's you couldn't even manually shift 1rst to 2nd.

 

Yes, because you are manually putting it in 1st. Think of the oposite if you put a car in 1st and drive around it will stay in first untile you manually swich gears.

"although i would never recomend doing this! When going 20-30Mph in a IROC-Z Automatic, If you move it from D to 1, should it shift down or not?"

Zippy might have a point but that just might be the the newer a4ld electronic auto 4speeds
"700r4's are dumb"

 

Mine downshifts when I do that. Mine is an 89.

 

I have an 89 Iroc with 2.73 gears.

Whenever I downshift like that, it waits until it gets to about 20-30 or so before it actually shifts into first... I don't think you'll ever get it to shift into redline though, that's just unhealthy.

My friend has a 91 Firebird, his is the same way.

Why would you want to do that anyways? If you want to shift into first, just floor it... the tranny should shift into first if it can. If not, you can't make any power in the redline anyways, so there's no point in it.

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89 iroc-z 305 tbi
k&n filtercharger, open element air filter. nuffin' else

 

Hey guys you hit on a ques. I've been
wondering about myself my trans seem to be
working fine but will not let me shift to
first at any speed including stopped, all
other gears I can manualy shift to but
first gear. but everything seems to work
just fine.
prob. should be on trans board but I saw
this topic here and jumped on, sorry.

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TPIS airfoil,relocated MAT,AFPR,TB h2o bypass
March Underdrive Pulleys
otherwise stock 5.0TPI
700r4, 10 bolt 3.23 g92 axle, 4 wh. disc brks.

 

The reason I was doing it was because I was test driving the car. Not like id do it all the time.

 

I have an 86 IROC that had 2.73 gears, and I have basicly full manual control over the tranny (outside of fourth gear)...a neighbor has an 87 IROC with the 9 bolt and I beleive it came stock with like 3.27 gears, or something weird...his tranny shifts him to second at 3900 RPM even with the shifter still in first! He can hold it out in all other gears, but not first...

I think the reason GM did that was when you take the 3.06 ratio of the 700R4 and consider the 3.2x gear ratio in a lot of the cars, downshifting from third to first might mechanically force the motor to redline, if not worse depending on the speed at which you are initially traveling. This is one reason I like my 86....sure it's the "Armpit of the IROCS"...but with almost strictly 2.73 ratios in them (I think like 86% of the build last I saw...who knows if it was right), I can be doing 40 MPH, slam it into first and smoke the tires... not that I would ever suggest doing that if you want your tranny to last longer then 5k miles

 

I'll have to try it and let you know. Generally I use D to go forward, R to go back and P when I'm done! I would much rather to 1-2-3-4-5 to go forward ... ah, you get it.

 

Damn double posts ...

[This message has been edited by Allan (edited May 08, 2001).]

 

my 85 will downshift into 1st at any speed. its been worked over, but even when it was factory it would. at 30 mph with a 3.73 gear my tach is going to get silly fast if i hit 1st. im ready to hit the strip now

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85 IROC 350 11:1keith blacks,.555lift erson roller cam,1.5 crane roller rockers,edelbrock intake,holley 4150 750dbl pumper, nitrous oxide,full length heddman headers,true dual exhaust, 11"stall converter, 700R4, 3.73 locker