LS gearbox choices

[Craig7L]

Hi,
much information is included in this section i know, but whats the basic opinions on choices for a 450-550bhp (ish) LS derivative mid engine application.
Information on prices, bellhousings, adapter plates clutches etc will all help
Longevity for high mileage street use is a must and gearing of that which you would expect a supercar to be geared at

Either new or refurbed options considered.

[molleur]

I'm waiting on my SL-C using a LS-1/Porsche 930 LSD gearbox. Got lucky and paid
$3900 for it as freshly rebuilt. The clutch kit, flywheel, etc. from Kennedy Engineering will be approx another $1750.00. For the RCR build, no adaptor is needed as it is machined into the chassis mid-plate. Plan on 5-7K for your transaxle complete.

[Craig7L]

hi molleur,
any idea of what your LS-1 will be putting out and what these G50 boxes are good for?
Not sure on LS-1 as i will be having to meet Euro4 emissions?, may well go LS3 or LS7 if i am tempted...any thoughts..?

[CRASH33]

I don't see how the LS3 can be beat for HP to $$. You're looking at 430 HP and 430 ft lbs. A 930, from the people I've talked to, will handle it, but not so sure about the G50s. The Mendeola SDR MAY be an option, and The Ricardo is definitely an option if you buy your kit through RCR.

[molleur]

the LS-3 or LS-7 engine can't be beat. Either the 930 or (read$$$) Ricardo is best in my opinion. My LS-1 is 420hp/390 torque. moved the power band up about 1000rpm
(camshaft) with subsequent loss in torque on the high end. I don't see this as an issue in a 2200 pound street car. The LS-7 and Ricardo combination is best (again in my opinion) but as a near $30,000.00 option quite expensive. I would go this way say, if I won the lottery!

[Craig7L]

seems theres quite a few options for the engine/trans combo for the coupe.
trying to get my head around real world street benefit of 505bhp as apposed to 450bhp where with LS7 i would definately mate with ricardo.

Would go with fiorano's 335/30s rears on standard 11" wide wheels.

Ratios would also determine street usability and performance but would try to gear as best as possible for stunning 0-100s and 70s-140s.

A benefit for us brits at the moment is exchange which makes a new 505bhp V8 with New Ricardo package price acceptable

I want to be in a postion with a firm shopping list when i visit RCR in 3 weeks time. (whats weather doing in detroit at the moment)

anybody got any gear ratio info on ricardo and 930

cheers guys

[Russ Noble]

930

1st 2.25
2nd 1.3
3rd 0.89
4th 0.64

with 4.22 diff gives

1st 9.495
2nd 5.486
3rd 3.756
4th 2.701

with 26" rears gives speeds in the gears @ 6000 rpm of

1st 49 mph
2nd 85 mph
3rd 123 mph
4th 171 mph

The magic 200mph comes up at 7000 rpm in 4th!

[Craig7L]

thanks russ..

whats the difference in gearbox of the 930 and 996 C2 porsche? which G50 variant?

[Russ Noble]

No idea Craig, I'm not a Porsche expert.

Try this though Porsche G50-G96

[J. Salmon]

The LS7 power is overkill, I will admit. But when you look at the complete package, I think it just makes sense. Particularly the dry sump. In an SLC, if you do not go dry sump, I think you are really taking a chance. A friend with an Ultima and an LS based motor with a huge race pan is in the process of converting to dry sump after getting starvation on public roads. He did say that the 680 hp he has was not worth the money (cannot get it to the ground) but 550ish should at least be manageable.

I also like the Ricardo for the really tall ratios. With a light car and big HP, it's much easier to manage the power delivery.

It's hard not to lean to the LS7-Ricardo package, if you ask me.

[CRASH33]

I'm just so surprised that virtually no one talks about traction control on these kit cars. I WILL have it on mine.

BTW- Just ordered my LS3. Under $7k with computer and complete harness. Just the engine was under $6k. Call this guy if you are interested. Joe @ 858-688-8801. He's a rep for a GM Performance Parts Dealer here in San Diego.

[J. Salmon]

Originally Posted by crash33

I'm just so surprised that virtually no one talks about traction control on these kit cars. I WILL have it on mine.

I am using the FAST traction control option with my EFI. $250, worth every penny.

[CRASH33]

I wasn't familiar with the FAST line of products. Have you used the ECUs before? Have you used a Haltech or Motec for comparison? I was looking at a Davis Technologies TC unit, but they are thousands just for the TC. Tell me what you know about the FAST products.....or maybe we should move this over to the engine threads?

[Craig7L]

heya crash.. you ordered an LS3 then.? for the SL-C?

what came with the crate engine for the money? what ECU did it come with?
cheers mate

[CRASH33]

I may do a GTM. It's more my style. Although I like the aluminum tub much better than the tube frame. I am used to working with the tube frame though and may redo the rear of the GTM as well. Again, kinda like the SLC, I want longer arms and better space for a real difuser along with true rocker arm shocks.

The GM guy says it's the factory harness and ECU. It's not what I will probably end up running, but it will provide the neccesary items if I decide to try and referree it with the LS3 installed. I'm still considering a 1964 engine for a start. Factory harnesses have previously been about $1000-$1500 and the ECU between $400-$800, so less than a thousand for both was hard to pass up.

The engine came with everything that is in the picture that is on many GM Performance sites according to the rep. That would be complete from intake manifold to oil pan. It includes a flexplate, but no accessories like A/C, alternator, or PS pump.

He said they are getting it directly from the factory and it would take two weeks or so to get. He offered me that he would get one from another dealer out of state if I was in a hurry, but since I'm just accumulating parts right now, it's not really a problem to me. I'll wait and get the newest item I can direct from GM. I'll try and remember to get you an update once I take delivery of what specifically was on it and what is needed to fire it.

[Craig7L]

that sounds a good deal.. i have to be careful with ECM mapping etc as strict Euro4 on turnkey cars here. will have to go with GM engine spec to begin with also wether its LS3 or LS7. Agree on traction control and all that so what ever i do will also be keeping one eye open for future mods ;-)

[John Lowe]

Hope I'm not to late with this post.

I am fitting an LS7 into my RCR40. The new Quaife ZF-Q complete with Quaife Bell Housing (which can fit either LS or Ford) is the route I am going down. Pm if you want more info

John

[CRASH33]

Can you give a rough estimate of cost on the ZFQ? Are those available in the states? If so, do you know from who?

[John Lowe]

The guy to talk to is Chris Melia on 0044 1638 510136 in the UK. There is an excellent thread in manufacturers announcements on this Forum showing the full ZF-Q development story. As I understand it most of the first batch were shipped to the US earlier this year for installation in Superformance 40's.

Mine is part of the second batch due in a few weeks. Not sure on pricing in the US, certainly they aint cheap but boy are they beautiful and good for 600bhp. Have talked to a couple of guys in the UK who have them installed (one behind a 525bhp injected Rousch) and they have given posative feedback especially on how slick the change is.

Let me know how you get on.

Best

John

[Erik Johnson]

Hey there Craig,

The G50 is more then capable for your application. We do them all the time here, as we specialize in the porsche gearboxes.

If you are going to be running under 600HP then you will be fine with a basic G50 5 speed. I would recommend switching out the 4th and 5th gearsets with taller gears, as this change will give you better cruising RPM.

I would be happy to discuss your options some time if you would like to give me a call.

Cost involved would be roughly in the neighborhood of $8500.00 shipped with the taller 4th and 5th, as well as a 12 month / 12,000 mile warranty. This would be for a completely fresh rebuilt unit. We have had great success with these in the past.

If you are planning on running a higher HP number then 600 then there are some other porsche options for you to consider, cost would be a bit more, but should be less then either the Mendeola, or Ricardo options.

We would certainly like the opportunity to help you out there, so let me know if there is anything that I can help you with.

Hope that this information has been helpful.

Warmest Regards,


Erik Johnson
Carquip Sales
(303) 443-1343 ext 2 work
(720) 980-9407 cell