Has anybody install one of those tranny with the west coast fiero kit?

I talked to them a while back. They recommend the NSX tranny over the G6 6 speed (F40). The funny thing is if you look up the specs for both, the F40 has a higher torque rating if I remember right, and it's considerably cheaper to do. Some people say a 6 speed isn't worth it, but Archie and some other guys are putting F40's behind V8's, so it must not be too bad. Bottom line, no I haven't but it's not the more economical route to go as far as 6 speeds go, and I honestly think it's a waste now that the F40 is an option.

Edited to fix some grammar

[This message has been edited by mptighe (edited 10-07-2009).]

jscottt1 swaped in a 6 spd behind his 4.9

Has anyone done a 3800 swap + F40 6 speed?

quote Originally posted by Valkyrie: Has anyone done a 3800 swap + F40 6 speed?

As far as I know, nobody has completed one yet....but there are several of us that are in progress.

Hmm... Interesting. I thought for sure at least one would be done by now. What are the setbacks that are keeping this swap from being accomplished?

quote Originally posted by Valkyrie: What are the setbacks that are keeping this swap from being accomplished?

Generally the custom flywheel/clutch package that needs to be engineered. I don't believe anyone has completed this portion for the 3800SC yet.

quote Originally posted by 1986 Fiero GT: Generally the custom flywheel/clutch package that needs to be engineered. I don't believe anyone has completed this portion for the 3800SC yet.

Archie makes a kit for the V8's, but no one is currently making a conversion kit for the 3800. This is also the setup I plan on using, so I will be keeping an eye on the guys that are doing it right now.

Does anybody have pros and cons for the nsx 6 spd and g6 f40 6spd, respectively?

quote Originally posted by Valkyrie: What are the setbacks that are keeping this swap from being accomplished?

Time and money on my end. I think most of the people that are doing it are also trying to do it with a small budget, along with having many other customizations on our plate at the same time. I don't know of anyone that is doing an F40 swap into an already working 3800SC install.

Pros and cons? Well....I can't comment on the performance of the two. I have ridden in an F40/SBC car, but haven't driven either one...but...
F40....cheaper and easier to find, bolt pattern matches the FWD GM bolt pattern, easier shift linkages
NSX....more expensive, requires modification to the cradle and frame, has similar issues with axles that the F40 has, more difficult shift linkages and hydraulics issues, and it is just plain wrong to put Japanese crap into our American cars.

The NSX tranny seems to have the same installation issues that the F40 has, plus a few extras. If you aren't a DIYer...you can get the NSX kit from WCF, or you can get the F40 kit from Archie and work the flywheel out yourself (dimensions have been pretty much figured out). Price is comparable for the full kits....but for a DIYer, the F40 seems much easier.

Speed comparisons....I used the speed calculator at http://cowspatoot.com/utilities.html and entered the gear ratios of the NSX to compare them to the F40. At 6000 rpm with a 25" tire, your speed will be:

code:

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                First         Second         Third          Fourth          Fifth           Sixth
F40          33.3           61.6             95.2          132.3           165.4          202.7
NSX         35.8           56.1             76.9            97.6           120.2          153.2
Getrag      35.3          60.3              89.6          131.5           171.7

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Note that it is not a stock tire size. So...do you want it to be quick, or do you want gas mileage and a low cruising RPM? Personally, I think the 3800SC has the torque for the taller gearing, and I would rather be running 1775 rpm at 60 in 6th rather than 2350 rpm.

[This message has been edited by CowsPatoot (edited 10-08-2009).]

How come nobody ever considered modern Getrag trannies outside of the GM family? (They're designed by Getrag anyways) If you're already using an adapter plate, there are trannies from: MINI, Mazda(speed), VW/Audi, etc. A lot of these trannies have tons of aftermarket support and really high torque ratings.. I understand GM doesn't have many high torque manual FWD applications. Other suppliers do though. (sometimes with options to replace the gears with straight cut, or Dogbox in the aftermarket)

I understand it requires fabrication and research, but it will be harder and harder to find a suitable NSX tranny down the road. The F-40's with the alternate gearing are also a finite supply.

[This message has been edited by Austrian Import (edited 10-08-2009).]

The NSX transmissions have way better gear ratios than the F40.

quote Originally posted by Steven Snyder: The NSX transmissions have way better gear ratios than the F40.

On Paper maybe...fortunately we don't drive paper.

I think far too much is made about the F40 gear ratios. I'd much rather shift through 6 gears no matter what the ratio compared to a self-shifting slush box.

quote Originally posted by 1986 Fiero GT: Generally the custom flywheel/clutch package that needs to be engineered. I don't believe anyone has completed this portion for the 3800SC yet.

I am getting to it one day but I am running a 3.4 turbo. The Camaro, Firebird flywheels are the thickness needed. I have the Flywheel from my 3.4 engine and when I get around to it I will just bolt up the stock 3.4 Firebird flywheel. The 3800 F bodies have one of their own also. I have the new six speed and a few other parts. I need to get the SS axles and the Grand am adapter for the plug on the slave line that you can just plug and play it. I have not decided on shifters but working on a six speed one that might work. I took measurements and posted it on the DIY six speed thread.

i have a NSX swap that is about 1-2 months from completion . I am running a series III , with some minor mods and a tilton clutch. I will post my thoughts on the trans aswell as any videos or request that are made that I can fulfill . one thing about that chart that was posted , it would be more usefull if it also showed RPMs. From what I gather first to second on the f40 is quite the jump.

quote Originally posted by Kemp3: one thing about that chart that was posted , it would be more usefull if it also showed RPMs. From what I gather first to second on the f40 is quite the jump.

quote Originally posted by CowsPatoot: At 6000 rpm with a 25" tire, your speed will be:

BTW, thanks for the chart CowsPatoot

Shifting at 6000 rpm, you will be at the following RPM when you enter these gears. This shows how much of a drop there is (rounded down to the nearest 25 rpm). Tire size is irrelevant for this comparison.

code:

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                           second            third            fourth             fifth            sixth
F40                       3275             3875            4325              4800           4900
NSX                      3825             4375            4725              4875           4700
Getrag                   3500             4025            4075             4575

---

Here is something else to consider....if you want to run a quarter mile in this thing, you will need 5 gears (possibly 6) with the NSX tranny....that is 4-5 shifts in about 12 seconds......compared to the two shifts required on the F40 or the Getrag. But I admit...if you want to do a road course.....with the NSX tranny you will always have a gear that will give you the perfect RPM for taking the curve at.

quote Originally posted by Steven Snyder: The NSX transmissions have way better gear ratios than the F40.

Maybe if your swapping in a V-Tec engine. The F40 is capable of actually getting decent gas mileage with larger engines. I wouldn't want to be spinning near 3000 RPM at 70 (cruising speed) with my V8 all the way from Atlanta to Daytona. If you have a wide torque band the F40 has better gear ratios. If you have a very peaky torque band you may be better off with the NSX tranny. In any case, I have two brand new spair F40 transaxles that were bought for about $250. You can't get NSX trannies for anywhere close to that.
On the plus side, the NSX comes with a true LSD.

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87 GT Tilt Clip-Widebody-RamAir-Fastback-GlassHatch Powered by SBC 383 6-speed w/ NOS
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quote Originally posted by ClayTonto: Maybe if your swapping in a V-Tec engine. The F40 is capable of actually getting decent gas mileage with larger engines. I wouldn't want to be spinning near 3000 RPM at 70 (cruising speed) with my V8 all the way from Atlanta to Daytona. If you have a wide torque band the F40 has better gear ratios. If you have a very peaky torque band you may be better off with the NSX tranny. In any case, I have two brand new spair F40 transaxles that were bought for about $250. You can't get NSX trannies for anywhere close to that. On the plus side, the NSX comes with a true LSD.

http://www.quaife.co.uk/Saa...box-ATB-differential Quaife makes a Helical LSD for the f40.

quote Originally posted by ClayTonto: If you have a wide torque band the F40 has better gear ratios.

Exactly...with a 4.9 I'm shifting WAAAY before 6,000 rpm and with the peak torque down low I don't feel the negative effects of the F40 gear ratios.

quote Originally posted by ClayTonto: I have two brand new spair F40 transaxles that were bought for about $250.

I hate you....