Getting 600+ bhp - questions

[bam_bam]

LSx?
What gearbox does it use, G50? I've all of the GT40 rep guys use 01E.

[Mɐʇʇ]

Nah. Audi V8 actually. I like the motor in my RS6, so I have an NA version for the ultima (albeit the 32V not the 40V version). 01E is an old box now, so I have a 6 speed 01X. Spent ages mapping all the gear ratios out to get the best match for it too. It's an old Ultima Spyder, not one of the new ones. (It's the the best looking Ultima Spyder ever built, IMVHO)

[mavada]

I think the Ultima GT-R used a Porsche gearbox bolted straight into the adapter plate on the RS6C5 engine.

[Mɐʇʇ]

Yeah, I've actually got a spare G50 in the garage.
But the ratios are a poor match and I didn't want turbo.

(This time)

[PipRS6]

I think with hybrid turbos, sports cat and a decent map you should be able to achieve up to 600. People are getting 560+ on a standard turbos with decat and remap (but at the top end). Suspect the hybrid turbos would give you a bit more. You might reach 600. Is it worth it, though?

Sorry to hijack but whats needed to get 560 on standard turbos? I have decat and remap and am just over 500bhp. What is the missing link now?

[Daveperc]

OK - it's shifting the gas volumes through the system that limits. So in your case I'd look at bigger I/C's (Waggies or similar) and then you need bigger exhaust (Milltek or similar) and possibly 3" DP's.

I would also suggest that you get the Map looked at - sounds like there's more to be had there already as MRC generally push 500BHP+ on Stage 1 (ie no other mods).

Dave

[PipRS6]

OK - it's shifting the gas volumes through the system that limits. So in your case I'd look at bigger I/C's (Waggies or similar) and then you need bigger exhaust (Milltek or similar) and possibly 3" DP's.

I would also suggest that you get the Map looked at - sounds like there's more to be had there already as MRC generally push 500BHP+ on Stage 1 (ie no other mods).

Dave

Thanks for the reply. I should have been more specific. I have wagner I/C's and miltek 3" and it was mapped by MRC. Maybe the previous owner was just being conservative.... Will have to get it on the rollers and see.

[Daveperc]

OK - I'd be back to MRC as that's well below what your setup should be capable of. You say in your original post that you have "Decat" - presume you mean that the pre-cats have been removed.

Mine was mapped to 523BHP (with your set up) but mine was tuned for torque rather than power to exploit my 517Trans box.

To get to 560 I suspect you will need 3" DP's, and possibly sports (200 cell) cats rather than the standard ones.

Dave

[PipRS6]

OK - I'd be back to MRC as that's well below what your setup should be capable of. You say in your original post that you have "Decat" - presume you mean that the pre-cats have been removed.

Mine was mapped to 523BHP (with your set up) but mine was tuned for torque rather than power to exploit my 517Trans box.

To get to 560 I suspect you will need 3" DP's, and possibly sports (200 cell) cats rather than the standard ones.

Dave

Thanks for the reply. I haven't been under to check yet but the previous owner said it was decatted but it still passed the MOT with the precats. So I assume the other way round, the main cats have been replaced and the precats are still there.

[Daveperc]

It shouldn't pass the MOT!! They are supposed now to physically check the Cat's are there now I believe.

Removing pre-cats which are in the DP's is basically invisible to a tester, and the main cats will be fine when warm so should pass without a problem (mine always has).

It's the precats which restrict the flow and whose removal therefore gives the increase in power.

Either way it sounds like a new set of straight through 3" DP's are what you need along with a remap to deal with Lamda delete etc.

Dave

[PipRS6]

It shouldn't pass the MOT!! They are supposed now to physically check the Cat's are there now I believe.

Removing pre-cats which are in the DP's is basically invisible to a tester, and the main cats will be fine when warm so should pass without a problem (mine always has).

It's the precats which restrict the flow and whose removal therefore gives the increase in power.

Either way it sounds like a new set of straight through 3" DP's are what you need along with a remap to deal with Lamda delete etc.

Dave

To be fair he didn't really seem to know much about what he was saying so I won't know for sure until I get under there and have a look.

[V!per]

So
The Beast is finally back.
Got the results of all the tweaking as well. As you can see it's a bit far off the 600 mark Although if you can see the temp - 34 Degrees outside !!! - on the ICs it was around 70 !!! If you bare that in mind, in lower temps this should be around 560 bhp(maybe slightly more). So yes a de-cat or a nice set of sport cats would probably bring it really close to the target.
I'm well chuffed in the way it goes and it is really nice and smooth drive. Now just need to do some cosmetics on the car - front bumper needs a bit of paint touch-up and wheels would do with a refurb.

[Weiß-sechs]

Not familiar with KM power output but a quick Google shows that 528 KM equates to 520 PS...that's quite low if you've had the hybrid turbos fitted.
Pre cats need going if not already and get her to MRC

[V!per]

Not familiar with KM power output but a quick Google shows that 528 KM equates to 520 PS...that's quite low if you've had the hybrid turbos fitted.
Pre cats need going if not already and get her to MRC

It's actually 535 PS
And I can't really get the CATs off - won't pass the emissions without them. And as I mentioned it was really hot when tested - should see probably 30 ponies (30.4 PS) extra in cooler temps. - that would bring it to 560 whicz I expected with the CATs on

[Daveperc]

And I can't really get the CATs off

It's not the cats that need to go, it's the pre-cats in the DP's - makes a big difference to the back pressure on the turbo. Better still fit 3"DP's (with no pre-cats in).

Enjoy!!