disclaimer: I realize that part of the following is based on a F-body platform weighing considrably more than an RX-7. I guess we should also keep in mind that a Z06 has quite a bit more rubber than we can fit on our cars without substantial modification.

In this LS1 tech poll 71% of the 85 voters picked a 4.1 over 3.73. http://www.ls1tech.com/forums/showthread.php?t=334040

Another testimonial "So I finally had my gears installed! I am 100% satisfied with these. Many people have mentioned on here that these gears should have come stock, I agree. I was worried that after the install I wouldn't be able to hook but that really isn't the case. I have Eagle F1's on the back 275/40/17 and I can break 1st loose if I try but I can go 7/8 throttle and dead hook in first it's quite nice! 1st runs out to 38mph, 2-60, 3-80, 4-112....Its like 1,2,3,4 are nuts, then you have 5th and 6th that are out there, however 5th pulls quite nicely at higher speeds. In 6th at 70 is around 1900rpm. I know my car pulls just as well as day 1, but I have adapted to its pull and am getting used to it. After 4.10 its damn right scary! Racing from a roll on the highway is crazy! Anyhow, if your considering this....do it as long as you don't plan on using ET streets or something crazy...be careful with the cappy 10bolt."

-Vertigo on LSTech

another:

"I've got the Strange 4:10's just like HOSS and I've put almost 400 miles on them already to attempt to break them in as quick as possible. There is a slight hum at 65mph and above, but that's all.

I had my speedo calibrated for them and at 70mph, I'm right at 2k rpm. My friends car with the stock gears is at 1700 at the same speed, so only about a 300 rpm increase. I haven't broken them in completely yet, so I haven't gotten into it, but I can already tell a significant acceleration improvement. I drive it everyday in traffic and it's still just as easy to drive as the stock gears were."
__________________
2000 Blk TA
Pacesetter LT's, Hooker ORY, Hooker Catback, SLP Lid, Strange 4.10's, BMR SFC's, BMR Sways, Pro 5.0 w/ Lou's Short Stick


by Trent on LS1Tech



Since I'm using an LS6 powerplant I decided to head over to z06vette.com:

"3.9
6500 43.6 62.6 90.6 129.6 154.2 ----
6800 45.6 65.5 94.8 135.5 161.4 ----
4.1
6500 41.5 59.5 86.2 123.2 146.7 ----
6800 43.4 62.3 90.2 128.9 153.5 ----


This should help with your question. 4:10 at 6,500 is 123.2mph.

Iv'e read a ton of post and most indicate the 4:10's are harder to hook. I suppose this all depends on you HP curve and tire combination.

A friend has them, it's super fun on the freeway 4th feels like 3rd 5th like 4th and so on. If you like running on the fwy, hard to beat to 60-140.

Around town it kinda sucks as you shift a lot more and first is worthless IMO. If it's a weekend car you will like it, a daily driver it gets old quick. He just changed to 3.73's as he is using the car as a daily drive now. I think the polls favor the 3.90 as the best all around gear. Getag only builds a 3.73, some say the case cannot handle the 3.90, 4.10's. Do a search on 3.73 gears, 3.90 gears, etc . You will find lots of good info to help with your decision.
__________________"

-Z06 Machine

"I had 3.90's in my Z06 and the revs in the lower gears came up really fast. I would think 4.10's would be even more so."

-Msiska

 

more off of LS6Vette.Com:

"4.10 Gears and Computer Edit
Okay guys, I've hooked up with a highly competent, well-known pit crew chief with numberous national and international titles under his belt, including at least one win at the Indy 500. I showed him my car and got to taking about what I can do next to get the most bang for the buck. He has done research and has elicited the help of one particular c5 racer, who shall remain nameless. The very first thing recommended was gears. After calculating all of the different options, it appears to them and me that a 4.1 ration would yield incredible results. So, my question to you guys is, has anyone put a 4.1 gear ration into their Z06 and if so, did it fit correctly within the housing and how did it improve (or hinder) performance?

Second, once I make this (and after future) modification(s), I will need to reprogram the computer. Is the LS6 edit the way to go, or should I use a Diablo chip? If the LS6 is the way to go (I will not perform the edit myself; I'll leave that to the pit crew) where can a get the program and what is the expense?

P.S. Once I'm done with this modification, I'll tell you what they recommend as the next "extremely helpful" modification that I haven't seen done by many guys.
__________________
Stacey J. Manning, J.D.
"All go... that IS the show"



A 4.10 gear would be perfect for 1/4-mile racing, if your trap speeds are under 124 mph, putting the engine in the meat of the power band in 4th gear for most of the last 1/8 mile. You should pick up at least a tenth and at least 1.5 mph. You lose a little in the 1/8 mile, though, because you have an extra gear shift to make (3rd good for only ~86 mph). If your trap speeds are 124 mph or higher, you need a taller gear to avoid a lazy shift to 5th.

Top speed should benefit as well. 5th will be good for ~148, and 6th should see ~185.

BTW, how does the PCM get its speed input from the transmission (assuming that's where it gets it)?
__________________

'02 Z06, TR/BK, GHL Magnum Plus, modified airbox, Green Filter,
Optima RedTop, shorty antenna, 6 turns lower
Last edited by johnboy00 : 10-31-2002 at 08:54 AM.



The speedo reads off the ring gear. No changes need to be made as far as the computer. The 4.10 will fit right in. No modifications. I prefer the MN6 trans with a 4.10. The gear spacing is much better.I was contemplating doing just that in my Z06.
__________________
A&A CORVETTE PERFORMANCE - " Your C5, C6 and Z06 Performance Specialist"
477 Lambert St. Oxnard Ca 93036 - Shop 805 278 4107 Cell 805 479 5885
Custom engines and Supercharger Systems are our specialty!
WWW.AACORVETTE.COM

My speedo will remain correct? I guess if I don't have to change the computer, that is a good thing. What is the difference between the MN6 tranny and the one that is in the '02 Z06? How is the gear spacing better? Is changing to the MN6 absolutely necessary? As far a 1/4 mile times are concerned, I am thinking not so much about drag racing, but rather performance on a road track. It sounds like the rear end is definately a good change to make. But, now I am confused about whether to to 3.90 or 4.10. The mechanic recommends 4.10."

- Waterfreak

 

I will be switching over to a 3.90 rear with s4 t2 lsd soon (if I ever get it back from the shop) and will report back results. Honestly the only reason I am switching to the 3.90 is to avoid going to 5th in the 1/4, as I would go through the traps close to redline(6800) and out of my powerband. The 4.10's are fine otherwise...

 

I think 4.1 is prefferable for my application but I can see how someone building a daily driven LS might get tired of the frequent shifting. I think the pluses are: slightly better trap times, if you can make traction (and are into drag racing), better acceleration out of corners, better highway acceleration and in general a harder pull. A top speed of approximately 185 with the 4.1 is still more than I'll ever use and I think around town you could probably even get away with starting in 2nd gear if you are in a high-traffic situation.

Who knows, 3.9 might be the bread and butter for this setup but I'm going to stick with the 4.1 r/p ratio and I'll be sure to post my impressions once I get her running.

anyone with hands on experience have an opinion on this?

 

That makes sense. I would think that a 4.1 would probably be better for road racing.

good choice on the diff, I'm using the same ;o)

 

- and chromolly axles that I got from Jodeny back in the day; he cut me a real good deal.

 

I should be getting my car back in a couple of weeks from H.S.C. I also went to the LS6 instead of the LS1. Hinson is doing some mods to the car that will help me get the most from the motor without stressing it out. I'm glad to see someone else went with the LS6, most people go with the LS1.

I changed from the 4.10 to the 3.90 for fuel economy. I plan on doing track days and some of the multiple track races that are held and hope this car will be more reliable than my autox car.

07 SM2 Spank1
Spank2 LS6 should be dynoed at 440 hp to the wheels.

 

Would you mind describing what Hinson is doing with the motor? I'm interested and it would be great to know while it is still out. We should keep in touch and help each other out ;o)

take care,
Rob

 

You do realize the LS1 and LS6 are basically identical minus head/cam, right?

Something to keep in mind about 4.10s in F-Bodies, is that they are substantially heavier. 4.10s in these cars make launching a real SOB.

 

a quote from my first post

"disclaimer: I realize that part of the following is based on a F-body platform weighing considrably more than an RX-7. I guess we should also keep in mind that a Z06 has quite a bit more rubber than we can fit on our cars without substantial modification."

"You do realize the LS1 and LS6 are basically identical minus head/cam, right?"

Externally you are correct. Internally there are enough differences to make it worth while in my eyes. I think most people who decide to do a heads and cam LS1 end up spending more money to acheive what the LS6 does out of the box. But to each his own and I wish anybody luck with whatever they chose to do.

take it easy,
Rob

 

Hey Rob, I have not responded to the post about the LS1 and LS6 being basically the same. I agree with the post but as you say, there are enough differences to also disagree. I believe that the LS6 is the motor to have unless you go with new LS7.

Hinson is doing the swap for me. I have heard lots of great things about them and felt that if I really wanted a great V8 RX7 then to do it right should be done by the people that are known for doing it right. They are doing everything involved with the swap, as well as a few extra things that I feel will improve the car. This car will be my street car as well as track day and multiple event race programs with me and a buddy.

When I get my car back it will be as follows.

01 LS6 with GM hot cam plus related parts to make it work right.
Underdrive Pully
Long tube headers into single exhaust already on the car. The exhaust will not have a cat due to where I live in ID we have no emissions. However I will be having a mid pipe made with a cat and cut out since I plan on entering the car in the SCC shoot out next year.
HPTuner package
Intake

Thats it. Intake and exhaust to make the car breath better. Better cam to take advantage of the better breathing. Underdrive pully to reduce drag, and dyno tuning with the HPTuner package to get the most out of the car.

I will be running a aluminum flywheel, and 3.9 gears. Flywheel to improve response and 3.9 for fuel economy plus keep the motor in the powerband.

My autox car is a fully prepared SM2 RX7 that is one of the fastest autox car in the nation, and I mean that. If you look at dyno slips you will see one of my car and I cut they dyno at 6500 since I was not working on the top end.

My street car is a 94 touring, montego blue with the moonroof. It will have the LS6 and should be more than fast enough as well as far more reliable for racing than my autox car is. Don't get me wrong I love my autox car but I have built it specifically for autoxing. This will be my street car and track car.

The 3rd gen has the best body lines but as we both know is tempermental. This swap I believe allows to have the best of both worlds. Great looks, great handling as well as plenty of reliable power. My street car will also be running eibach springs with GAB super R shocks. I will be running CCW 17x10 wheels with Goodyear Eagle F1 tires.

The RX7 with the swap and the T56 get up to 30 mpg on the freeway. Well I tell you what, show me any mazda in the US, that can put down 400+ hp on street gas, not ever have to worry about a coolant seal going out, and get 30 mpg on the freeway. The T56 that I have in the car also has the .50 6th gear so that combined with the 3.9 rear gear will put my final ratio at 1.95. I should be running at 1700 rpm's at 75 mph.

When it came to deciding which motor to go with it was like this. I could get a LS1 and put some money into it for a good motor with more power. However knowing me I would always be thinking, "I should have put in the LS6 and put the same bolt ones". So since I know this is how I am I just did it.

So now that I have talked your head off, tell me what you think about your car.

Allan

 

Sorry, I missed that. I have a tendency to read without comprehending sometimes.

What are the internal differences between an 02 LS1 and an 02 LS6? I just rebuilt my LS1, and I used all the 02 LS6 parts, and every internal part had the same part number as the LS1 counterpart minus the block on the bottom end. Am I missing something here? (not being a smart ***, just curious).

 

Let me look and I will give you one of the links I have looked at to find out the difference. I am like you, I do not know alot about the LS1 or LS6. When I was deciding which to go with I just started doing the research to find out the difference. I will look around tomorrow and see if I can find the one page that had a great article on the differences.

Allan

 

I'm with you 100% Allan,

I'm the same way. I knew that if I hadn't gone with the 6 I would have regreted it in the long run, not to detract from the LS1 because it isn't too much different but I've always been a fan of the Z06's powerplant. I've been toying with the idea of using an intercooled procharger w/ 7lb pulley to make aprox 500hp but first things first, I need to get her running and see what she feels like. When all is said in done I think 400+rwhp is probably going to be more than enough especial considering my wheel choice. I'll be running my OEM 99 spec 17" 5-spokers powdercoated a gunmetal grey color with 255s out back and 245s in the front. I've yet to choose the tires. I am not considering a turbo with this car because there is just not enough room to do things the way that I'd want to do them. My intention is to build a prestine car to keep forever but and use for occassional track days at Summit. As far as my setup goes, I'm using Hinson mounting equipment with a 03 LS6 that I picked up with just 3k miles. I've been looking at TKO-600 trannys but I think I'm going to end up going with a low-mileage t56. I'll be using all F-body accesories, TB and ECU with JTR headers, hinson aluminum driveshaft, chromolly axles, t2 converted diff, willwood BBK, mazaspeed suspension bushings, labreck nylon diff bushings, RE trailing arms, Mazda 929 master cylinder conversion, poly engine mounts, Tenabe SS Pro coilovers, RB swaybar and brace, front brake ducts, an aeromotive fuel pump feeding from a sumped tank through AN8 lines, and I'll probably just see if I can talk ZKeller into helping me tune it ;o). Nothing too crazy but it is quickly turning into my dream car.

I think you made the right choice going with Hinson. They may not have the fastest turnaround but they are definitely the authority when it comes to V87 swaps. I'ver talk to Brian several times and he seems like a nice enough guy.

I'd like to see some info and pictures of your autoX car. Sounds like a bad machine.

-Rob

 

LS6 introduced with the upgraded LS1 block added, bulkhead windows allow for better crank case breathing.

http://www.corvetteactioncenter.com/...06/ls1ls6.html

2001 LS1 vs. 2001 LS6

350 @ 5,600 385 @ 6,000
Torque (lb-ft @ rpm) 375 @ 4,400(manual)
360 @ 4,000(auto.) 385 @ 4,800
Redline (rpm) 6,000 6,500
Fuel Cutoff 6,200 6,600
Compression Ratio 10.1:1 10.5:1
Manufacturing Origin St. Catherines, Ontario
Total Dressed Engine Weight Auto. - 457.6 lbs. (208 kg);
Manual - 497.2 lbs (226 kg) 497.2 lbs (226 kg)

What attracted me was the redline increase from 6k to 6,500RPM. I did a lot of reading on the head design, the engineers went to great lengths to design a light valvetrain which allows the LS6 to make more power and higher up at that.

In 2002 the ls6 got an extra boost of 20 hp, to 405.

"This upgrade to the LS6 engine's output is the result of new hollow stem valves, a higher-lift camshaft, a low restriction mass air flow (MAF) sensor and a new low restriction air cleaner design." Z06vette.com


So yes the only major difference is the heads/valvetrain and cam combo aside from the improved block ventilation and rev capabilities, but that kinda goes back to my earlier point. I guess you could say that there are very few differences besides the heads and cams but if you ask me that is just enough reason to buy the LS6. I bought it for the heads, cams, improved block design, increased compression ratio, increased rev limits, higher power band etc. Yes you can make an LS1 perform like an LS6 but it takes time, labor and parts all of which are not free. You get what I'm saying.

take it easy,
Rob

 

An ls6 with headers, hot cam, bolt ons and a tune may make 400+rwhp, but I doubt anywhere near 440. You're going to need a more radical camshaft or some good heads to achieve those #'s.

 

Yeah you're probably right. That was just an ambiguous estimate. Just over 400 with stock interneals and JTR headers is all I'm after.

Got any pictures of your install?