Discussion
I am a TVR convert ....
I am looking at a project to increase the power on an Ultima to around 800bhp at the fly, it has the G50 six speed box (not sure which model as I havnt picked it up yet). Basically to run at 200mph + what gearbox ratios would it need, and any ideas as to where I could have that done?
I spoke to the factory who said that the box should be ok to take the power.
Is it also possible to have a short shifter fitted?
Sorry if its a little vague but Ill provide more info on the box when I have it.
TX
I am looking at a project to increase the power on an Ultima to around 800bhp at the fly, it has the G50 six speed box (not sure which model as I havnt picked it up yet). Basically to run at 200mph + what gearbox ratios would it need, and any ideas as to where I could have that done?
I spoke to the factory who said that the box should be ok to take the power.
Is it also possible to have a short shifter fitted?
Sorry if its a little vague but Ill provide more info on the box when I have it.
TX
I talked to Elite Racing Transmissions, a UK base company. They can do one off's, at a price that was comparable to PHII. I did not have much success when I phoned PHII, very off-hand and said they do batch runs, needing 10 to 20 before making anything, providing it is not already in stock (13 week lead time etc etc). What I wanted was not in stock, they didn't offer to take my details, so how can they ever batch them up...
Thanks Pete - Im more photogenic holding that trophy than Adrian anyway 
btw send me your E mail & ill send you the pictures. mine is tora@freeuk.com
Cheers
JK
btw send me your E mail & ill send you the pictures. mine is tora@freeuk.com
Cheers
JK
Wilder said:
Tx I will gice Elite a call...
You might also check with California Motorsports. They have 25 years now of building Porshe transaxles.Builder said:
Wilder said:
Tx I will gice Elite a call...
You might also check with California Motorsports. They have 25 years now of building Porshe transaxles.
Just had a reply from Roger, lots of goodinfo there, especially on ratios up to 237mph available!. Funny but Powerhaus want to sell me a new GT3 box that they say is more suited than the G50.
As the factory run the mighty 720 without mods or problems, I think Ill take a chance on the G50 with revised ratios. Lots of differing views on how stong the box is, and how it will or will not cope.
I may check some of the suggestions such as lighter gears/cooling but the more information offered the better so please keep it coming.
TX
As the factory run the mighty 720 without mods or problems, I think Ill take a chance on the G50 with revised ratios. Lots of differing views on how stong the box is, and how it will or will not cope.
I may check some of the suggestions such as lighter gears/cooling but the more information offered the better so please keep it coming.
TX
It will depend on your G50 as not all G50's are equal. The GT2/3 box's run the largest G50 internals so if you have the strongest G50 already there would be little point upgrading.... its unlikelly you do though.
How do you plan to make 800bhp? is it via NA or forced induction and is it still a SBC?
How do you plan to make 800bhp? is it via NA or forced induction and is it still a SBC?
Its by ProCharger. They reckon 800bhp, though I can reduce that if needed by simply reducing to cog size.
The gearbox is deffinatley the issue here though Im not sure which of the 6 sp models it is, and interestingly the factory seem to think that the gearbox may be able to cope with close to that figure.
The gearbox is deffinatley the issue here though Im not sure which of the 6 sp models it is, and interestingly the factory seem to think that the gearbox may be able to cope with close to that figure.
Wilder said:
The ProCharger people are very helpful. The charger is a F1 which is a higher rating than the DSC version Dave has. That may not necessarily be a good thing, but I know theres scope to boost it by altering the cog size if at some stage the gearbox can be reinforced/ replaced.
Hi JonathanYou don't need an F1 to get to 800hp. The D1SC ProCharger I have is more than capable of doing the job. You are going to need to re-build or build a new engine with low compression to get to than level of power. Why 800hp Jonathan are you on a quest? It will be a lot of work to fit a Procharger into a GTR, maybe not as much as a Can-Am! Are you planning on doing the work yourself or is someone going to do it for you? Are you going for a blow-through carb or going fuel injection? If you fancy a chat about it send me a mail for my phone number!
I'm adding more boost over the winter and fitting water/methanol injection. My quest continues!
Regards Dave
It's not the BHP but the torque that is important, a porsche box will probably only cope with 800ftlb if you pamper it which sort of defeats the point... it could take 800bhp if the torque was around 650ftlb.
The factory cars produce their power (BHP) via revs so a 700bhp engine will have about 600ftlb, a charger will produce it via torque which will mean 800bhp engine will have 800ftlb and if used hard (and it genuinelly has 800ftlb) I don't think a G50 will cope.
Best person to speak to is Jeff from the states as he's producing these levels of power from turbocharged LS7's so has experience in this area.
The factory cars produce their power (BHP) via revs so a 700bhp engine will have about 600ftlb, a charger will produce it via torque which will mean 800bhp engine will have 800ftlb and if used hard (and it genuinelly has 800ftlb) I don't think a G50 will cope.
Best person to speak to is Jeff from the states as he's producing these levels of power from turbocharged LS7's so has experience in this area.
Its funny the engines the easy part!
There are all sorts of things that can be used to strngthen the box as mentioned by Jeff. Some things almost sound straight out of a science fiction book -bottom line is its possible, but needs planning.
I want a car that will do 200mph in a standing mile, but that can be driven on the road also.
Looking at some of the road monsters out there, it must be feasible, and I want to see what can be done.
The engine in there is the 383 Ci (6.3) Chevy, with 550bhp /515 lb/ft so as Andy mentioned the torque is the problem more than the bhp.
If the problems become too much, then I would consider dropping the power close to the factory 720, as I know that runs a standard unmodified box, and they say its stood up to all the abuse given it.
Any thoughts would be appreciated.
There are all sorts of things that can be used to strngthen the box as mentioned by Jeff. Some things almost sound straight out of a science fiction book -bottom line is its possible, but needs planning.
I want a car that will do 200mph in a standing mile, but that can be driven on the road also.
Looking at some of the road monsters out there, it must be feasible, and I want to see what can be done.
The engine in there is the 383 Ci (6.3) Chevy, with 550bhp /515 lb/ft so as Andy mentioned the torque is the problem more than the bhp.
If the problems become too much, then I would consider dropping the power close to the factory 720, as I know that runs a standard unmodified box, and they say its stood up to all the abuse given it.
Any thoughts would be appreciated.
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