Sequential twin turbos vs simultaneous

Just wondering if many TT owners have their turbos set up so they can run at the same time, rather than sequentially. Apparently it's an easy job to do, and it can be switched between the two modes via a switch on the dash, but is that true? Also what are the pros/cons?

I changed to TTC in my auto and hated it, more sound, sluggish as hell below 3k revs and a smooth surge after 3k similar to how a single would deliver....not nice with smal twins

TBH TTC is for the 6 Speed boys, one of the best feel good mod I have on the car.

Pros, Less fuel, Better mid range response, Others will disagree (Normally the auto boy's lol), but speak to Nic he has a dyno plot to prove what i have just said, Mental sounding Exhaust.

Cons, low down response is very poor, as you get full boost at 4k RPM.

Love it or hate it jobbie:D

I did mine as well. I had it mapped on emanage by thor (although they just pulled some timing so I could run 95 ron). It was not good!

Very laggy, (same a a big laggy single but with 1/4 the power)pretty unrewarding to drive, no good on the motorway, and massive drone...

Just a case of swapping a couple of pipes over though - can be done in a few seconds.

Mine went back to sequential after a few weeks, although I did up the pressure on the 1st turbo a little - was far better imho.

ive been thinking to try this, might give it a go, see what its like

I did mine as well. I had it mapped on emanage by thor (although they just pulled some timing so I could run 95 ron). It was not good!

 

Very laggy, (same a a big laggy single but with 1/4 the power)pretty unrewarding to drive, no good on the motorway, and massive drone...

 

Just a case of swapping a couple of pipes over though - can be done in a few seconds.

 

Mine went back to sequential after a few weeks, although I did up the pressure on the 1st turbo a little - was far better imho.

Are you Auto?

See this thread

http://www.mkivsupra.net/vbb/showthread.php?t=94697

And keep an eye on the speedo, My cars BPU only and running TTC

Lag is only noticeable in first gear, but once you get going you will always be at full boost.

you only just fucking braked in time on that exhaust note one, lol

you only just fucking braked in time on that exhaust note one, lol

Hehehe,

J spec 2 pot jobbies aswell.

The supra I had in TTC was my second silver one.. 6speed.

Your car looks bloody quick! I had 2 bpu's 6 speeds, a blue 96 which was really strong - needed a new clutch - it overpowered the stock at 1.2 bar, and the second '94 silver which was not even close.

I really disliked the TTC personally, it's a bit like marmite though, everyone is different!

edit;

I noticed your revs don't drop much! - I'm quite a lazy driver which is why I like power low down. I had Terry swap my new car's turbo down from a GT40 to a GT35.. it makes positive boost at 1.5k.

suppose it might be a diffrent kettle of fish on an auto eh

Sounds and looks like a single in the manual lol

The supra I had in TTC was my second silver one.. 6speed.

 

Your car looks bloody quick! I had 2 bpu's 6 speeds, a blue 96 which was really strong - needed a new clutch - it overpowered the stock at 1.2 bar, and the second '94 silver which was not even close.

 

I really disliked the TTC personally, it's a bit like marmite though, everyone is different!

You said it lol,

MARMITE:D

Well after hearing some of these comments, i'm not sure if the TTC conversion has been done properly, you need to wire open the EGCV and the IACV to be sure of getting the full benefit, i suspect that some of the reasons for the feelings of bad response and late full boost are down to a pressure tank problem or bad actuators, i went TTC about six months ago and i have no desire to go back, with a little tweak to the timing with an emanage any perceived sluggishness low down can be sorted, i myself never really noticed a big difference, my turbos are spooling by 2,500 RPM and on full boost by 3,200 RPM, midrange response is better fuel consumption is far better, and turbo response is strong but smooth, no more waiting for 4,000 RPM until you can make decent boost, much better for winter roads;) i got Fed up with town driving in sequential mode, you can't squirt it out of junctions etc, or out of bends without loosing traction

but then i am used to single turbo cars before the Supra,

if you want to eventually go single try this first, it gives the same king of feeling and response;)

I absolutely hated it! In TTC mode the car makes a horrible drony sound even at idle. On the motorway it was unbearable. Still, easier to power slide with TTC!

any good guides about on how to do this proporly?

If there's a switch involved, then surely you can use one mode for town driving, and the other for motorway

looks like there is 2 ways, electronically so you can switch the 2

http://www.mkiv.com/techarticles/ettc/index.html

And ive not found the other one i assume its just moving some vac pipes about

Edit, ah here

http://www.mkiv.com/techarticles/ttc/ttc.htm

Americans calling everything checkvalves, Is that just a none return valve?

WKD can you tell us which option you did, the electronic one or the ghetto one? lol

As i said there are different ways to do it, one is electronically, another is to switch the vac pipes around, but both of these will only work if the pressure tank and pipework and VSVs are OK, the only effective way of converting in the long run is wiring the EGCV and IACV open, there are guides to all methods available if you do a search.

I drove Matt Harwood's 6sp car with it done (so I'm confident it was done 'right' ), and absolutely hated it. I had toyed with it for myself, and I know that I could drive around it, but I like my low end response, and it robbed the car of all of it.

ive got it done on mine, got a switch hidden away so i can switch between the two settings. Tbh i dont like the TTC mode, just dosent feel right to me.

but speak to Nic he has a dyno plot to prove what i have just said, Mental sounding Exhaust.

Dyno comparison HERE

I liked the parallel setup, yes you loose low down, but gain mid range, you need to adapt your driving to suit the setup ie. you need to keep the revs higher so you can be on boost.

Mine was mapped with the emanage to suit the parallel setup, I wouldn't do it otherwise.

ive got it done on mine, got a switch hidden away so i can switch between the two settings. Tbh i dont like the TTC mode, just dosent feel right to me.

From some of the comments on here (ie: Tricky-Ricky), I'm begining to think it might be done wrong, or at least have something missed off! Cos it certainly doesn't do ANYTHING at all below 4k rpm!!! Only a very slight boost between about 2k and 3k or something, then at 4k both spin up suddenly and the wheels start spinning (sound about right Pete?) - doesn't feel like it's doing the turbos any good, and doesn't feel nice to drive at all!! I can't believe that's how a single runs.

Mine was mapped with the emanage to suit the parallel setup, I wouldn't do it otherwise.

My thoughts exactly - so I took it to Thor to map on emanage and, when I got back and had a look, they did nothing but retard the ignition (I asked for safety on 95ron fuel), I presume they thought that no fueling work needed to be done..?

my turbos are spooling by 2,500 RPM and on full boost by 3,200 RPM, midrange response is better

this is not what I found - but mine was held open by actuator pressure... maybe you have to wire them open or not bother...!

Mine was no boost until 3.3 then full boost at 4k. That's probably worse than a big single...

If mine had made power at the RPM's you quoted I'd have been happy at that! Full boost by 3.2... that's good stuff!

Has anyone else tried the wired method and the pluming method on the same car?