[Mk2] [Turbo] Twin Turbo/Twin Charging

[Shmed]

Surely research into a different final drive ratio is going to be most cost effective. Far more cost effective than compound charging an (unforged?) engine where it hasn't been done before!

That said, I'd love to see it done.

Didn't Shmed buy Simon Hick's awesome 2.2 5S car?

Yep

[Shmed]

I already have traction control (thankfully), and anti lag was considered, but not allowed in TSS.

Deep down, I'm just a tinkerer. I like the idea of a sequential dog box... I also like the idea of twin charging... I don't have much budget though so think the exhaust change will suffice for now, but enquiries will be made to Mr Dent as I like the sound of his SC setup!

[gavsdavs]

On a slightly seperate subject....

Recent Porsche 911s use twin, variable geometry turbos.
*I think* variable geometry relates to the impellor - at low revs the vanes are in one position to be able to spool on low gas flow, as revs rise the vanes change position to react less to higher flow.

The question is - are there any 'aftermarket' turbochargers which use variable geometry ? If not why not ?

Sounds like a very sensible way to overcome lag

(I don't really understand how they work, so I have guessed)

[MR2 Rich]

Surely research into a different final drive ratio is going to be most cost effective. Far more cost effective than compound charging an (unforged?) engine where it hasn't been done before!

That said, I'd love to see it done.

Didn't Shmed buy Simon Hick's awesome 2.2 5S car?

Yep

Thought so. What ECU do you run?

[Shmed]

I was trying to find some info from the Borg Warner site as they seem to cite variable geometry turbos. The thing I keep finding online is that 'they' say, Tein turbo is less used because of modern turbo design. Trouble is, we don't all have modern turbos. So if they are available, then perhaps that is the golden bullet!

[Shmed]

Didn't Shmed buy Simon Hick's awesome 2.2 5S car?

Yep

Thought so. What ECU do you run?

It's got a Syvecs S6 with Traction control. I'm hoping to enter TSS one day so am trying to keep within regs (hence no anti lag or nitrous). I'm also not looking for more top end power, I just mentioned de-tuning to get it more track friendly, and a bit of sick came up!

[gavsdavs]

Can i suggest spending the money on driver training and aero/handling mods instead of just aiming for more power ?

[Shmed]

Can i suggest spending the money on driver training and aero/handling mods instead of just aiming for more power ?

Yes, all suggestions welcome, but not sure where to go in terms of handling mods. I have a few ideas on aero, but can't be ar$ed at the minute with them. I already have coilovers, white line ARBs, torsion rods and Tein strut braces, lightweight wheels so think I'm pretty much there in handling mods. The obvious elephant in the room is weight loss which I'm still toying with, but when I go for weight loss, I'll go so far that the car will become a dedicated track car (as in not road legal) so a fairly big decision.

Just to reiterate, I'm not chasing more power. 550HP Is more than sufficient for the track, I just want a more track friendly power curve, ie pulling from 3k and still generating GT35 levels of power.

[gavsdavs]

....I just want a more track friendly power curve, ie pulling from 3k and still generating GT35 levels of power.

I was getting wheelspin in 3rd at 2k rpm on saturday. But Pete's n/a was a LOT faster.

[Shmed]

Was that in the wet? Maybe my traction control is doing more than I think because I wasn't getting much wheelspin on mine even when boosting... Though I didn't do much driving when the track was wet

[bobhatton]

You have got this kit fitted I hope if you want the best handling and use a Rev 1 subframe.

http://www.imoc.co.uk/forums/viewtopic.php?t=176246

[gavsdavs]

Was that in the wet? Maybe my traction control is doing more than I think because I wasn't getting much wheelspin on mine even when boosting... Though I didn't do much driving when the track was wet

Yes...your car is a lot more powerful than mine, but maybe mine produces more torque low down.
It was damn slippy in places.
I have no TC or ABS.

[Shmed]

but maybe mine produces more torque low down.

Definitely agree with this . That is the crux of this thread really. I want more low down power.

I also have no ABS, proven by me skidding straight on at The Ump.....

[gavsdavs]

....I want more low down power.

Supercharged 2gr

[Shmed]

....I want more low down power.

Supercharged 2gr

But I also want crazy top end power as well

[fingers99]

GT35RS?

Not sure what's out there at the moment, but it seems like Garrett have filled in a lot of the holes in the range.

Was chatting to some guy in Brazil who wanted a 400 bhp T Jet (on ethanol) and was considering a species of GT28R. "Nuts!" said I, "too damn big!" But on closer look, Mr G had something with a rather complicated code that looked like it would do the job.

[Shmed]

So who voted 'brilliant idea I want to help you do it cheap'? How can you help

At the minute I'm thinking of leaving it alone. I've swapped the exhaust to the 'goose and need to get it on track again. If I can give it beans without bein pulled over for too much noise then I think that'll do. I've seen a Radical I like and might switch to that....

[ashley]

http://www.radicalsportscars.com/uk/rxc/

http://www.radicalsportscars.com/global ... ase_v1.pdf

[Shmed]

As nice as that is, the price tag is a shade high for my budget

I have seen an SR3 that looks decent and it costs a lot less

Decided that I'm going to make the two a dedicated (non road legal) track car when the tax runs out in November.

[greeny]

Can i suggest spending the money on driver training and aero/handling mods instead of just aiming for more power ?

Yes, all suggestions welcome, but not sure where to go in terms of handling mods. I have a few ideas on aero, but can't be ar$ed at the minute with them. I already have coilovers, white line ARBs, torsion rods and Tein strut braces, lightweight wheels so think I'm pretty much there in handling mods. The obvious elephant in the room is weight loss which I'm still toying with, but when I go for weight loss, I'll go so far that the car will become a dedicated track car (as in not road legal) so a fairly big decision.

Just to reiterate, I'm not chasing more power. 550HP Is more than sufficient for the track, I just want a more track friendly power curve, ie pulling from 3k and still generating GT35 levels of power.

Get a smaller and newer turbo that will still provide 550hp and spool faster. You're leaving some on the table with the 35r if you're only wanting 550hp.

Can also try brake boosting into the corners if you're brave enough