Re: 4.10 gears...not what I expected.
 

From another perspective - the recent Mountain Run some of us did last week:

Shortly before doing the run, I had a chance to experience Brett's 350 LT5 thru (4.10s). There is NO QUESTION the seat of the pants could feel the increase in punch over my 3.45 cog (allowing a little to maybe an extra ≈ 30 hp for the bigger cams in Brett's car).

But, as others have said, 6th gear in the mountains was pretty much useless, except above 70 on flat stretches. I believe a bigger ratio would have been useful in the hilly terrain. Even with a lot of the time spent in 2nd and 3rd gears and sustaining 3000 to 4000 rpm** over some stretches of curves, there were times when I was dropping into 1st (remember altitude plays a role too). A little more "dig" would have been welcome; it would have put the LT5 into its sweet spot - above 5000 rpm+ more easily.

**From the perspective of lingering in the 3000-4000 rpm range, it occurred to me that would put an LSx or perhaps even the new LT1 (C7 motor) right in their sweet (torque) spot - assuming at or close to the same rear gear ratio. Those LSx motors' (torque) peaks earlier (at less rpm) compared to the LT5, and in that particular application they would out-pull the LT5s unless the ZR-1 had something like the 4.10 ratio to bring the LT5 rpm into its prime torque vs. rpm range too.

That said, the results from last year's running of the 1/2 mile in Monee clearly showed where the LT5s shine. As Pete mentioned, the LT5s are obviously long-legged; pretty much dominating LS motors at that event in spite of the LS boys having a cubic inch advantage. (limited to NA motors, that is). I would attribute that to the fact that venue favors motors with peak hp in the high rpm range. The 3.45 geared Zs did very well for themselves! But, there were reports from the 4.10 geared LT5 guys that in that venue the cars would nose over when hitting 5th gear (somewhere above 120 mph).

So, the 4.10s in any one gear will increase torque at the wheels, and thus acceleration - in that gear, taken on the whole in a distance/speed venue vs. a hilly/twisty course (with altitude tossed in) ether the 3.45 or the 4.10s have their special place.

For now, I will admit the 4.10s are fun, especially on the street. But, taken on the whole - the extra shift in the 1/4 mile mitigates most of the advantage of the 4.10 gear for the ZR-1; at least for that venue (maybe if one power shifts, the extra shift could maybe be overcome to result in favor of the 4.10s...but not with MY ZF transmission - thank you very much!!). AND, hitting the 1/2 mile at the top of 4th with the 3.45 - is about as ideal as you can get for that application.

The 3.45s are evidently pretty good "all round" for speed/distance up to 1/2 mile contests (sans possibly power shifting). However, for mountain thrills...the 4.10s would have been VERY nice to have. It boils down to the venue, I recon. Too bad we don't have quick-change rear differentials like we had in modified stock (dirt track) racing. In under 20 minutes you could change the ratio to fit the speed/rpm equation for that track.

I'm thinking I'd love the 4.10s for street and cruising the twisties. But, for speed/distance contests, the 3.45s - up to 1/2 mile - it's pretty hard to beat the versatility. Even if one goes with a compromise between 3.45 and 4.10 (or 4.30s?) that gear too would favor certain venues at the expense of some other. Decisions, decisions....:( Maybe the answer is to have multiple Zs, each with different ratios and simply choose the Z that fits the situation. Yeah... I LIKE that idea!

Re: 4.10 gears...not what I expected.
 

It seems too much might not be enough, meaning the extra shift into fourth gear is offsetting any positive impact of torque multiplication when using the 4.10 ratio. Why not use a 3.73 ratio which will give a smaller torque multiplying advantage, but will keep you in third gear in the 7000 rpm range through the traps.
And so it goes....Jim

Re: 4.10 gears...an update on my conclusions.
 

So, I've had these new gears for a week now, and I am ready to amend my initial comments. Those comments, as I've said earlier, were based upon overly-inflated expectations that had gone unrealized. I also want to reiterate that I know Marc's "18% more torque" claim is 100% true. I NEVER doubted Marc and never wanted to give the impression that I doubted him and if I did that, I apologize to all, and especially Marc. My point was that I didn't FEEL 18% more torque, not that I thought it wasn't really there.

1) The car moves away from a stop much more easily and requires less slipping of the clutch. It gives the impression of a smaller, lighter car.

2) As Marc says, it does get to the "meat" of the power band more quickly, which is great.

3) The upper gears are definitely more useful.

To anyone considering this gear change, my advice would be to consider it more of a "driveability" upgrade than a "performance" upgrade. In my opinion, the overall character of the LT5 does seem to work a little better with the shorter gearing, which lends credence to the claim that the engineers originally designed this drivetrain with these gears in mind. Just don't expect the thing to take flight the first time you hammer it, like I did!

Re: 4.10 gears...not what I expected.
 

Yeah... That's where hp elbows its way into the discussion. For example, I (and several others here in FBI country) are @ or above 500 hp. I go through the traps at 121 mph and just as my shift light comes on (at 7100 rpm). A 3.73 would require a shift to 4th before the traps.

However, a 3.73 may be correct for a stock motor. When mine was stock, I ran 112 mph in the traps at about 6600. A 3.73 might be a good stock motor ratio.

This echos back to what Lee says - that being power mods are what makes the big difference, at least in the ZR-1/ 1/4 mile performance.

Re: 4.10 gears...not what I expected.
 

Here's another food for thought.
Two ZR-1's run same 1/4 MPH one has 4.10's the other has stock 3.45.
Guess which is winning from a 40-50-60-70-80-90-100 roll.

Pete

Re: 4.10 gears...not what I expected.
 

Im not a fan of steep gears myself. I have a little explanation that I tell people that Includes a Sumo wrestler vs Chuck Norris if anyone would like to hear it lol.

Trying to be as short as I can.. but to me gears are great if you are running 1/4 mile and 'quickness' means everything to you. If you can hook first gear, that steep ratio will help launch way harder and you will shave a noticeable amount off your e.t. For all other speeds besides launch gears are useless. The way I see it comparing 3rd gear with 4.09s and 2nd gear with stock gears is more relevant. Look at the speeds of those two final drives and you will see the multiplication difference and at the MPH that it occurs. People fail to take into consideration that yes gears multiply torque, but you are going slower in those gears. So 3rd feels faster.. but now you are only going the same speed as 2nd used to get to. SO really is your new faster 3rd much better than the old 2nd? that's how I see it.

Also the zf is a 5 speed + massive overdrive. reverse shares the same synchro as 6th so using 6th to accelerate [-X. Don't ask me how I know.

On my LT4 that spun 8k I dropped from 4.30 which was a waste of tires gear to 4.09. Which effectively made my trans a 3 speed (1-2 were useless) and went down to a 3.73. WIth the target troque being so high it effectively killed torque in the low range which was my goal and helped hook 1st gear on street tires. I also trapped 128 mph on low profile 19s at 44 psi on a road race suspension. Most races were well over in 4th anyways which was perfect since it topped out around 275 ish km/hr. Let the torque do the work which is what I like to say :)

Theres a reason the c6 z06 went numerically lower with a final drive. Torque. let the torque do the work. The viper is another example. It has a numerically low gear ratio (1st gen anyways) why? because its a truck motor and it doesn't like to rev. give it less gear and let the torque do the work. Its no secret viper owners got brainwashed by all the gears bs and put 4.10s and went to the track and went slower. In my opinion its one of the biggest mistakes people make with high hp/torque cars and why some dyno queens just cant make the mph and times on the road.

Re: 4.10 gears...not what I expected.
 

This echoes what a lot of folks homed in on with the 4.6 DOHC Cobras. A 3.73 or 4.10 was kind of considered what should have been the stock gear (3.27s in my year) but for 1/4mi work the conclusion was 4.30s or 4.56s - the mantra became "Don't fear the gear!". Apples and Oranges sure, but the curves, character, peaks and limits are similar. Note I did not say similar NA power!

Please note the above is secondhand but as a part of that community I watched a lot of efforts reaching that conclusion. I was autocrossing in stock class with my '99 so a gear change was something I could only lust after.

Now with the red car in *SP class I can, and hope to (someday) go to the 3.54. A lot of work for not much gain but still it is a gain, and that's racin'.

Cheers,
- Jeff

Re: 4.10 gears...not what I expected.
 

Curious, what PCM were you using on your 8000rpm LT4? Aftermarket? Stockers shut down after 7300-7400rpm.

The other reasons why the ZO6 and Viper went with a lower rear gear, was to be able to reach their top speeds with teh available transmissions.

Re: 4.10 gears...not what I expected.
 

All else equal, the 3.45 geared car will win from a roll. Unless you are rolling on in 5th gear.

Re: 4.10 gears...not what I expected.
 

If I had no idea what a ZR-1 was, and I was to go back and read this thread in its entirety, I would conclude that the ZR-1 serves one primary purpose: a 1/4 mile drag car. Virtually every poster mentions, above all else, 1/4 mile time, rpm, etc. Granted, I was curious as to whether any back-to-back acceleration comparisons had been done with the 2 gearsets, but I didn't change gears to ensure that I went through the trap at a specific rpm. That's just me, though.

Not saying there's anything wrong with it at all; I'm just kind of surprised that rpm in gears seems to be the most important factor in a potential gear swap. Just my observation.

Have a great holiday weekend, all! :cheers:

Re: 4.10 gears...not what I expected.
 

I'm using 3.73s BUT I also have taller 19" wheels which effectively makes my gearing ~ a 3.50. Lgaff and myself had nearly identical setup a few years ago w the exception of gearing. He had a 4.10 in his 92 red, I had 3.45s w 92 aqua. Bot were top end mods and had the same headers, Watsons. Lee was usually faster by about .3-.4 but our trap speeds were within 100ths of a mph. He would beat me to the 1/8th w a higher mph but by the end, I would be gaining on him. Pretty sure that after the 1/4, I would have overtaken him. Just some anecdotal evidence.

Re: 4.10 gears...not what I expected.
 

Which in my eyes shows the only advantage is having a shorter first gear. If you can take advantage of the increased torque at the tire in first it will get you ahead and then it's an even race until the shorter geared car hits 5th which is pretty much an overdrive then the stick geared car should catch and usually the race is well over before needing to go to 6th.

I ran a similar race when my 93 lt1 was bolt ons with 4.10s. When I started in 2nd gear from a 15 mph roll when the stock geared car was in 1st.. Were were pretty much neck and neck until I hit 5th. I would pull slightly and then lose it on the shift and repeated in every gear. If I launched hard in 1st I kept that advantage (about a car and a half) until I hit 5th where he would catch and pull slightly ahead before he hit 5th.

Personally I hated the gears back then. It was fun at first until I realized for all that extra push, I was moving at a slower speed in each gear. I started to miss that nice long uninterrupted pull.

Re: 4.10 gears...not what I expected.
 

No,it won't. From 60-120mph,all else being equal,a mildly modified ZR-1 w/4.10's will dust one w/3.45's. The car with lower gearing will pull harder to redline every time

Re: 4.10 gears...not what I expected.
 

I don't believe that's the case . It pulls harder to redline but you're shifting faster and the speed at which gear tops out at is much less. What I'm trying to say is assuming the stock geared car is in 2nd and the 4.10 car is in 3rd.. How is the 4.10 car accelerating harder ?

Final drive in 2nd gear with stock gears is : 1.8x3.45 =6.21
Final drive in 3rd gear with 410 gears is : 1.29x4.10 = 5.28

Speed for stock gear car is 60 mph and 4900 rpms. If you ask me that's right in the sweet spot

Speed for the 4.10 car at 60 mph is 5800 rpms in 2nd and if using second it has a more favorable final drive for the split second it takes to hit the limiter and then will lose that momentum in the shift to 3rd where the final drive favors the stock geared car again. At 74 mph in 3rd (assuming shift at 7200) the 4.10 car will be at a lower final drive than the stock geared car until the stock geared car needs to shift at 90 mph at which point the advantage goes back to the 4.10 car.

Confusing but it's back and forth depending on who's in the sweet spot if were talking roll on races . The only advantage in final drive a 4.10 car has is 1st gear because that is the lowest gear that is possible to use. If a 4.10 car has slicks and dumps at 7200 and hooks and launches a full 2 car lengths ahead.. It will maintain that because after first gear and shifting into second the final drive advantage goes back to the stock rear car that is still in 1st. And so it goes back and forth .. Get it ? THAT is why gears show a e.t difference but no difference in mph.


So my conclusion is .. 4.10 gears are great for a 1 gear advantage only. Off the line if you can hook. That's it. :)


The most common mistake I see people do is compare the SAME gear roll ons from a rear gear swap vs stock. That's not really fair to do because the speeds and ranges of the gears has now changed somewhat . In many cases the stock gear car should be in a lower gear where the final drive may be in it's favor for a brief period and pass it back and forth.

Re: 4.10 gears...not what I expected.
 

Lee was at top of 4th while I was topping out in 3rd at the end of the 1/4. I was gaining on him in the last 300'. He typically would have a higher 1/8th trap by about 1-2mph. But by the end of the 1/4, our Mph was nearly identical. The next shift would have reversed positions. We're talking about somewhere around 118mph. And frankly, Lee is a better driver than I am.

Re: 4.10 gears...not what I expected.
 

Michael,I said "all else being equal",did I not? How is one car being in 3rd gear and one in 4th, equal? Try a roll-on with both cars in the same gear,especially in 3rd gear or higher as that will take tire spin out of the equation,and get back to me.

Reading your last paragraph made me chuckle. How is all else equal not being fair?

You don't believe it to be the case? I have done 3rd,4th,and 5th gear roll-ons against other ZR-1's and did find it to be the case.

18% increase in torque doesn't lie,does it?

Re: 4.10 gears...not what I expected.
 

Sure,you were starting to reel him in. His LT5 was probably starting to run out of breath in 4th gear with those 4.10's. Whereas,at 120mph,your car with the 3.73's was still hitting its stride.
But,you didn't catch him,did you?

I won't argue the point that 3.45's aren't an excellent cog for top-end blasts over 120mph. But,I ask the question once again: How many times a year does your ZR-1 see speeds way over 120mph? Probably,not that often. How often do you find yourself driving down the expressway in 5th gear,instead of 6th? When my car still had the 3.45's,I caught myself doing it quite often. To be perfectly honest,I wouldn't mind if our 94 had 3.45 cogs because the Texas speed limits are 75mph or even higher.
But,I still prefer a little more acceleration over a little more top end. Different strokes for different folks,,

Re: 4.10 gears...not what I expected.
 

Well, 18% torque increase for any rpm is correct, but it is a bit simplistic: The torque curve is not flat across the rpm range, and speed at the top of every gear is going to be 18% less for any give rpm. The combination of rising and falling torque curves over rpm and the fact of some loss in speed/time for each shift apparently tends to mitigate a substantial amount of the advantage of the 4.10s for the ZR-1 in the 1/4 mile - or so it seems from observation.

And, to Dom's point, Those that ran the 1/2 mile drags in Monee last year, the 3.45 geared cars really featured the LT5's strong suit - faring much better at 140+ mph in 4th than that reported by the 4.10 guys - having to shift to 5th and experiencing the cars acceleration "dive" when they did so.

What is starting to emerge, sans any formal analysis here so far, is the 4.10s may not be big enough for either the 1/4 or even the 1/2 mile contest to make a clear, indisputable advantage over the stock 3.45 "cog", but only in part due to the extra shift. In both cases ending in 4th in the "quarter" or 5th in the 1/2, the LT5 is not at peak power. So, less than peak power in the trap PLUS the extra shift eats up most of the torque advantage of the 4.10 in either contest: just NOT quite enough gear. Something like a 4.3:1 gear might fix that, me thinks.

I like 5ABI VT's description of the "back and forth" advantage when comparing the two (3.45 vs. the4.10) in the quarter mile contest (and perhaps the 1/2 mile too). Not so clearly cut and dried as comparing gear ratios alone would suggest.

Interesting discussion.:)

Re: 4.10 gears...not what I expected.
 

I agree that is overly simplistic,Paul. Nothing is ever cut & dried. Just having fun with Michael. He's a good poster and has interesting opinions.

I also agree that 4.10's would not be my first choice for 1/2 mile drags or especially full mile runs. With those new racing venues,4.10's aren't as big a deal as they used to be when I owned my first two ZR-1's over ten years ago.

Re: 4.10 gears...not what I expected.
 

Modified or not, the facts are the same. The engine will accelerate to red line quicker with lower gearing but will the car will not accelerate harder. F=MA

You dont want lower gearing for roll racing(dead stop drag racing is different), nor do you want to roll race a manual trans against an auto trans, all else equal.

You cant directly compare 2 cars, you have to test the same car, then make changes and retest. All else is benchracing(which can also be enjoyable).

Re: 4.10 gears...not what I expected.
 

"The engine will accelerate to red line quicker with lower gearing but the car will not accelerate harder." Someone please explain this statement to me because it just doesn't make any sense. :neutral:

That's all I thought we were doing here,,benchracing and having fun. :):)

Re: 4.10 gears...not what I expected.
 

Minor correction: 120 mph with stock wheels the ZR-1 will be pretty close to 7000 rpm in 3rd gear, but we're talking a modded LT5 at those 1/4 mile speed levels (above 500 hp). A stock LT5 would be more likely at 110 mph at the top of 3rd gear with 3.73s, actually.;)

http://i185.photobucket.com/albums/x...ps837f03ef.jpg

Uh...more often than you might think!:dancing Gears are dandy, but horsepower ends the acceleration vs. top end compromise!

Re: 4.10 gears...not what I expected.
 

This bench racing is fun isn't it? It saves on parts :-D

I still think Pete could cut quicker times with 4.30's, or 4.56's (depending on tire). As he says, the 4.10's got him a 1.59 60ft. time, that's phenomenal, and a big advantage in the Qtr.

A .15 advantage in the first 60ft. is several car lengths in the traps. You don't lose that much, (maybe a fender), during the 3-4 shift.

That tells me that the 4.10's are not too much gear, but not enough. The reason his times got slower is not the third to fourth shift, but because he wasn't peaking out to 7,400-7,500 in the traps. The trick is getting the great launch AND peaking at the right rpm in the traps.

I see the stock gear as a disadvantage at launch. If he cuts 1.74 60 ft time with 550+h.p. and a stock gear, and I cut a 1.76 with 4.10's and a stock motor. How is that using all that horsepower that he's spent so much time and effort building? Just sayin' :confused:

More gear, more tire:eek:

Re: 4.10 gears...not what I expected.
 

Explaination:Just because the engine is revving to redline quicker(less time) doesnt necessarily mean that the car is also accelerating quicker. Think of a "block and tackle" a single pulley will be able to lift LESS weight, than 3 pulleys. But the single pulley will lift its weight by winding up less rope than the 3 pulley system. Though the 3 pulley system does move more weight, it also requires many more times the amount of rope to lift any weight. The single pulley being analogous to stock rear gears(3.45), and 3 pulleys being analogous to lower gearing(4.56).


Yes, bench racing is what we are doing here, and it's fun, so long we bring the Scope.

Re: 4.10 gears...not what I expected.
 

I don't agree. You don't have to go to a block and pulley analogy to explain it. Just look at 60ft. times.

If a ZR-1 cuts a 1.50 60ft., and another cuts a 1.60, who's accelerating harder?

The ZR-1 with 4.10's will cut a better 60ft. every time. All other things being equal.

Re: 4.10 gears...not what I expected.
 

I was told by someone who raced SuperStock for many years that a smaller gear absorbs more energy than a taller gear and so wheel spin is easier to control.
You need more rpm to turn the wheel once w a smaller gear.

Re: 4.10 gears...not what I expected.
 

The shorter gear actually allows you to apply more rpm, thereby more torque to the wheels at launch. Gears don't literally absorb energy.

It's really about leverage. Short gears give more leverage, but require more rpm to do it. The ZR-1 develops it's power at a higher rpm, therefore requires shorter gears.

Re: 4.10 gears...not what I expected.
 

Someone mentioned that a 4.10 gear isnt worth it for a 1/4 mile run based on the addition of a shift, and not trapping at peak power.
Then someone mentioned that the 4.10 may not have neen enough gear, perhaps a 4.30 or 4.56 is in order?
I would agree with that. So long as you can hook, your 60ft will decrease which will help 1/4 mile times. This is true because of the extra torque applied at launch, extra Force. This decreases as you move off the line as the engine approaches and passes peak power.

I had a drag vehicle that made peak power at 4800rpm. With 3.08 gears it would trap the 1/4 mile at 5500rpm in 2nd gear. Swapping to 4.10 gears allowed for a trap rpm of 5000rpm in 3rd gear. In this experience 60ft et dropped, 1/4 mile et dropped, but 1/4 mile speed also dropped 3-4mph.

Torque=Rotational force at any moment
Power=(Torque(lb/ft) x rpm)/5252
Acceleration=Change in velocity over time
Work=force which acts on an object which results in a displacement, if you push on a car with a force of 100 pounds, you are expending energy through your muscylar effort, but if the car doesnt move, no work has been accomplished Work=Force x Displacement
Mass=Vehicle weight

We also have to remember that when we shift from 4th(1:1) to 5th(0.75:1), or lets say the driveshaft rpm is 7,500rpm in 4th gear with a 7500 engine rpm in 4th, the same 7,500engine rpm becomes 10,000 driveshaft rpm, in 6th 0.50:1 would be 15,000rpm.

Some of the newer transmissions (TR6060) have less split from 4th to 5th, which helps reduce that nose-over feeling that some experience when shifting to OD.
Engine torque=400lb/ft
Rear Gear 3.45:1
Engine Torque x trans ratio x rear gear=torque applied to ground
400x2.66x3.45 =3671lb/ft
400x1.80x3.45-2484 lb/ft
400x1.30x3.45=1794 lb/ft
400x1.00x3.45=1380 lb/ft
400x0.75x3.45=1035 lb/ft
400x0.49x3.45=676 lb/ft

SO throwing a 4-5 upshift losses 345 lb/ft of applied torque combined with the fact that at this speed aerodynamic forces are increasing, thus adding to negative acceleration.

Fascinating discussion, so many variables. With the extended rpm potential of the LT5 conventionally agressive gearing, isnt so agressive when used with the LT5.

Re: 4.10 gears...not what I expected.
 

Re: 4.10 gears...not what I expected.
 

I had to go to a block and tackle as the other gentleman didnt understand.
My point was, that just because your tach reaches 7500rpm quickly, doesnt mean that your speedo is accelerating as quickly.

I agree with your drag scenario a car cuts a 1.50 60ft, and another hits a 1.6 60ft. The 1.5 60ft is accelerating harder.

I also agree, a 4.10 geared ZR-1 will cut better short times(60 ft) than a higher geared ZR-1, all else equal.

Now I ask you this, in your scenario ZR-1 #1 cuts a 1.50 60ft with its 4.10 gear, and ZR-1 #2 cuts a 1.60ft short time with its 3.45 gear.

Which ZR-1 will trap with the higher Speed MPH? All else equal.

Re: 4.10 gears...not what I expected.
 

The short, smart*ss answer is, It doesn't matter. Because the one with the best e.t. wins.
I don't pay much attention to trap speed because I dont' care how fast you're going in the traps if you're behind me. :p

With the 4.10 gears I trap 117+ with a stock motor and boltons. That's a whole lot better than my early efforts with stock gears that trapped a best of 110-111mph.

The short gears allow you to keep the engine up in it's most powerful rev range for more of the time during the race. Someone running the quarter in two or three gears spends more time climbing up to max power, as in your example. That's another way to explain the advantage of short gears.

Of course, those with a torque converter overcome that disadvantage in another way. But that's a whole other discussion.

Re: 4.10 gears...not what I expected.
 

Tee-hee, reason I asked about mph as it is the indicator of power, moreso than ET.

I've noticed that sometimes in a 1/4 mile drag situation, that with lower rear gears, that while ET can increase, trap mph can decrease, all else equal.
If I am reading correctly, you have been experiencing highr MPH trap speed with your lower gearing? Interesting.

xxxxxxxxxxxxxxxxxxxxxxxxxxx
I just ran some numbers:
7000rpm/3.45 gear/25.5"tire 1:1 4th gear gives 154mph
7000rpm/3.73/25.5"/4th gear gives 142mph
7000rpm/4.10.25.5"/4th gear is 130mph
7000rpm/4.30/25.5/4th gear gives 123mph
7000rpm/4.56/25.5/4th gear is 116mph
7000rpm/4.88/25.5/4th gear is 109mph
7000rpm/5.13/25.5/4th gear is 104mph, **** to 5th and 138mph is attaiable at 700rpm, then shift again into 6th gear and 211mph is attainable at 7000rpm. 5.13's in 6th gear at 70mph would be revving 2325rpm. 7000rpm in 1st gear with 5.13's gives you 39mph.

Looks like the amount of power the engine makes, will affect just what gearing you would need to run, IF the goal is best 1/4 mile ET.

The lower the rear gear (higher number) also helps to reduce driveshaft/trans/clutch/engine loading. Everything after, starting with the ring gear to the tires would experience increased loading.

Re: 4.10 gears...not what I expected.
 

If all else is equal,both LT5's make the same power or very close to it.
So,their trap speeds should be very close to the same. Only way that would be lower is if the engine is running out of breath at the lights.
As Bob said,only the ET matters in drag racing. MPH is just a by-product though it is a honest indicator of how much horsepower you're putting down.

Re: 4.10 gears...not what I expected.
 

Clint as rare is it might be I am one of those guys that have gone well past the 120 mark on many occasions. And I can say from my experience that top speed is achieved in 5th with the stock 3.45. When I shifted into 6th gear I fell from 182mph to 168mph in a hurry. At top speed I was pegged at 7200rpm's. 4:10's might make 6th gear useful but I wonder if I would run out of RPM's before reaching top speed with them.
I'm with Pete on this one. If I had $1,500 to burn on performance mods I go with the ones that are actually going to create more HP. Because more HP is just more. And with 3.45 your going to see gains in every way. Launch and top end. Id rather have the overall increase than one or the other. ;)

Re: 4.10 gears...not what I expected.
 

I have read most of these post and it is a fascinating discussion. The one thing that no one has brought up is how does the single mass fly wheel affect al of this. I have a 90 ZR-1 with Marc's 510 hp package. I also installed 4:10s a few years ago. With the single mass flywheel getting to the torque curve and Hp sweet spot much more quickly I am curious how this would impact the discussion. Personally I really like the 4:10s. I only drag race once or twice a year. I don't own drag radials so trying to hook the car is just about pointless from a dead stop but it does pretty well from even a first gear roll. I am curious what the opinion is on how a single mass fly wheel would impact this discussion. I can tell that I am thrilled with the result of Marcs 510 package the gears etc. The car now has some "edge " to it and makes it really fun to drive. I know it will take some drag radials to take advantage of the launch but I 1/4 racing was not the biggest priority in purchasing one of these cars.

Re: 4.10 gears...not what I expected.
 

I did. Look at post number 5.:-D

Re: 4.10 gears...not what I expected.
 

It's ok to disagree,Rick. Like I said earlier,different strokes for different folks.
I've been over 175mph too many times to count in my 90 ZR-1 while it still had 3.45's,,way over. Been over 200mph more than a few times too,on some of my turbo/nitrous prostreet bikes.
This is my 3rd ZR-1 so I've been around the block a few times,so to speak. :-D

Our 94 came with 4.10's when I bought it,a free mod.

BTW,good to see you posting again. Welcome back.

Re: 4.10 gears...not what I expected.
 

The Point being, if you want driveability, and NOT pure quarter mile performance, is the swap to 4;10's worth it?

I can already light up the tires at will with the 345's , if I drop to 4:10's it will only get worse?

I don't run 1/4 mile at all, just street driving.

Re: 4.10 gears...not what I expected.
 

If you want driveability, then yes, it is a great swap. I don't think I would do it again, given the same scenario of spending $1500 to have a mechanic complete the job. But if I was doing the work myself and only spending the $500 or so in parts, then yes, I would go for it. It changed the character of the car but surprisingly, it wasn't a lot more tail-happy. For what it sounds like you're looking to accomplish, it's a great swap.

Re: 4.10 gears...not what I expected.
 

I went from 3.45s to 3.73s due to the 19" Z06 wheels I have. It effectively bumped my rear from a 3.30 to ~ 3.55. The car felt more responsive to throttle changes. It became more fun to drive.