a few questions

[Richy rich]

i am considering building a gtr that will be for road and track use(limited road but must be legal).
i just want a bit of info!well quite alot really)
i have read that there is a 6 speed version of the g50 gearbox,is this true and what is the part no(g50/20?).
will the 6 speed fit the ultima o.k.?
has anyone used the quaife 6 speed transaxle gerbox,does it fit o.k.?
what is the minimum possible weight of the car,deleting aircon,electic mirrors,leather,twin skin ect?
what is the offsets and pcd,s for the wheels and how much do they weigh?
has anyone fitted 6 pot calipers and bigger discs(to a road legal car),and is a handbrake caliper available to clamp on to 355x32mm rear discs?are bigger discs and calipers needed or do the 4 pot a.p.'s work well?
what is the cd of the car and what is the weight distribution?

if i get answers to all this i will be a very happy chappie!!!!!lol

thanks in advance richy rich

[Steve_D]

Hi
Welcome to the forum.
1. The factory sell the 6 speed box used by Porsche but is in fact a Getrag. Sells for £3500 +VAT.
2. Quaif. Don't know.
3. Front minus tyre 9.5Kg. 18" X 9".
Hub face to outer rim face 120mm.
Rear minus tyre 11Kg. 18" X 13".
Hub face to outer rim face 130mm.
5 stud pattern same as Ford Granada.
4. The factory do a 355 X 36 so it will fit but the on they have is without dust seals so is not for road use.
Knowing that it fits you can try other makers for the spec you want. Ask the factory, they have probably been there.
5. CD weight dist. Don't know.
Steve

[JCof T.O.]

I think on the Ultima site the CD is .30 for the GTR. I believe that is with the wing.

[ultimaandy]

An Ultima is around 60% rear bias, my Can-am is 62% wet, this would obviously change when dry as the fuel tanks are more rear biased.

I am confident that a Can-am could be slimmed down to 800-850kgs dry as mine is 1000kgs wet (75litres fuel, 9litres oil, 10-14litres coolant) and I have steel block, full screen, hood, stereo and even sound deadening!

I am less sure about the GTR as it is a bit heavier but it should be possible to get it down to 900-950kgs dry. The factory demo car has these mods, what does that weigh?

Imagine 600bhp and 800kgs!
Do you recon Top Gear would be impressed

[Richy rich]

Cheers for the replys lads.The factory quote 990kg for a car with leather,aircon,twin skin and electric mirrors so about 950kg seems easy to get down to.
Are there companies that supply different ratio,s for the getrag box?Anyone compared the getrag against the g50?In my experience(limited..lol)cable changes seem to be less precise than a rod change!!60/40 distribution seems about right,my fiat coupe 20v turbo is about 63/37 but front bias rather than rear.Has anyone fitted racelogic traction control?
A cd of .30 seems really good if it includes that mahooooosive rear wing!!!!



Richy Rich

[Steve_D]

The radiator is steel framed with copper and brass inards. It weighs 18Kg with the fans.
An alloy version may be worth considering.

[G Man]

There is a G50 6 speed I run it in my GTR.
From a 993 type Porker

[Richy rich]

Steve,i think it may be better to lose more weight from the rear than the front to get nearer 50/50 distribution!How much weight do you save on a chevy engine with an aluminium block?Any ideas of the cost?

G-man,do you know the code for your gearbox and are there any aftermarked gears and lsd,s for it?Is it rod or cable change.Do you know what the standard ratios are?

Richy Rich

>> Edited by Richy rich on Friday 3rd January 02:52

[RSchley]

A somewhat common alternative to the heavy chevy v8 is to go with an alumninum LS6 GM Motor (I think LS1 is aluminum also). The LS6 is the engine used on the newer Corvettes, Cammaro and Trans-Am. JSchwartz uses one in his GTR, he would be more knowledgable about them, that is just some stuff I picked up.

[ultimaandy]

I think the alloy block will save about 40kgs, my complete turnkey engine with crate weighed less than 250kgs with a steel block.

Two potential problems.
1. an alloy block is around £4k.
2. The SVA may be a problem.

[Richy rich]

why is the sva a problem?
would i need the dreaded Q plate?


rich

[james]

You only need a Q plate if your car isn't made from all new parts (or if you can't tmake the SVA people believe that it's made from all new parts.

He's probably referring to emissions regs. Your car has to comply with the emissions regs that relate to the age of your engine. Therefore, if you go for an SBC, and you pretend that the block was produced before 1972, you don't need cats, and you can get away with just about anything when it comes to emissions. If you buy an LS6, which is a modern engine, you'll need cats, and you'll need to comply with much tighter emissions regs.

James

[G Man]

I have a alloy block you save 90 lbs, the SVA no problem if the alloy block was early 70's which comes from DART

The gearbox is a G50/21 it uses the Ultima rod connection
Check out http://members.rennlist.com/david_t/gears.htm for ratios

>> Edited by G Man on Friday 3rd January 15:59

[bubbles]

An e-mail I received today from Amerspeed state their engines dry, complete with the ancilliaries, weigh around 500lbs

P.S. Guy, alias Blue Satin has the Traction Control fitted from RaceLogic.

Dave

[ultimaandy]

500lbs is about right as per my shipping document.


As mentioned by James an alloy block can mean emmision problems unless you are really carefull.

New block (steel or alloy) would mean 2003 emision regs.

However Alloy blocks are possible, best bet is to speak to the factory or someone like GMAN.

[Alan 2]

ultimaandy said:

New block (steel or alloy) would mean 2003 emision regs.

Some confusion here. Just to put the record straight, GM has never produced steel blocks commercially. Most are made of cast iron (cheap, rigid and an easy material to work with). Cast iron has a much lower melting point than steel which makes it easier to pour into moulds.



>> Edited by Alan 2 on Friday 3rd January 20:23

[UltimaAnimal]

I am looking at fitting Brembo 6 pots on the front, ill let you know if they will fit. Pad surface area is 15% more compared to the AP racing versions and they come with seals for road use

[bigmack]

UltimaAnimal,
I have fit Brembo 4-pot X9.005 calipers to my Ultima. Its a racing caliper, but it has dust seals. No anti-rattle clips though. Brembo can provide you with a spec sheet that lists the minimum inside wheel diameter required for each caliper.
Cheers!
-Mack

[Richy rich]

i hope the brembos are not like the ones on my fiat,they are crap!!basically not rigid enough,they flex too much when braking hard.

i will stick with ap gear as i have used it in the past and not had any problems.you get what u pay for with brakes,imo!!

rich