Throttle Bodies etc.

[Alex 111s]

I'm considering installing throttle bodies as my next upgrade to the VVC, i'm assuming that i'd need to change ECU (Emarald) whilst doing this. (is this correct.)

what are the pros & cons in changing to TBs & ECU is improved performance worth the effort?
&
As with every uprade, some TBs must be better than others. any advice on good/bad products?


cheers

Alex

[tut]

Throttle bodies and an Emerald are normally required when you go for a more aggressive head which is going to produce upwards of 170hp, ie high lift cams, ported, gas flowed head with oversize inlet and exhaust valves, stronger valve springs etc.

You will also need a good 4-2-1 exhaust manifold to reclaim the mid range torque that can be lost with T/B's. Direct to head Jenveys are the normal cost effective route, but the Exige VHPD ones will also do the trick.

I am a bit out of date on the K series now, but I would think that the advice from Robin, Ali, FD, et al would be not worth spending that sort of money on a straight VVC head that is not going to be upgraded.

tut

[Alex 111s]

thanks Tut,

so to tap into real gains there's alot more to do, 4:2:1 exhaust manifold would still be on the list at some point but i'm not too keen in touching the head at the moment. might re-consider and use the cash on other things.

[Shug]

Tut talketh some truth

Most people would only consider the TB route after going big guns on the head, but I've not chosen to do that. The engine i bought (VVC, standard) came with an Emerald dyno readout of 167 bhp on a 4-2-1 & I had the TB's & ECU anyway. Bolted on my 4-2-1, TB's and Emerald & should be in the ballpark of 185bhp (according to Dave Andrews).

Good news is that it's got bags of torque and drivability (compared to my last engine, which was a big valve standard K head) plus it's got the rush to the redline factor that the TB's give. The VVC mech is only good for 7200 & power is tailing off there with the VVC cams, so I change at 7k. I figure it's a great starting point as it's a really drivable, fast engine which isn't massively overstressed (VVC pistons & liners are graded better) When I want to go silly, I can get solid cams & convert the VVC mech (£5-600) and go for 200bhp while the pistons last. After that, a 1.9 bottom end (about £1k) will see over 220bhp. I've also got a PRT & Oil cooler to protect it a bit. The point being that the VVC head is basically the same as the VHPD head, just with extra castings for the VVC mechs.

My 2c is that it's a valid upgrade path. Certainly doesn't seem to hold me back (will outdrag Elaine's 111r from a 2nd gear start (with her on-cam & caning it) all the way to silly tuts)

Put a 4-2-1 & TB's on it - pretty expensive, but the gains are stunning. If you see me at a meet, feel free to blag a go

[hiscot]

i have t bods on a std valve ported head with kent cams i did use a 6 stud vvc exhaust and found my torque to be fantastic ( just changed to a janspeed 421 ) i have heard the t bods give 15+ bhp depending on spec ie more bhp = more from t bods but thats only part of the advantage as shug says drivabilty is fantastic in any gear mine will pull from 2000rpm in 5th
i use ptp t bods but although they perform brilliant they would suit a larger port vvc or vhpd head even better , but factor in air box, air trunking and filter (again i have just replaced ) along with the ecu and any mapping however as shug says you have the best part of any further mods
i also have a prt and oil cooler another worth while mod imo

[robin]

Above 170 or so the engine wear is rapid and you run the risk of piston failure, especially if you plan on prolonged track usage.

IIRC the S2 VVC produces the best part of 160BHP already.

DVA does a nice upgrade for the VVC that involves a bit of tweaking to the head, exhaust manifold and some adjustment of the VVC mech to tweak the duration a bit further (as I understand it). I've seen the S2 variant of this produce 177BHP on two independent rolling roads, standard ECU. Makes the same power with either 48 or 52mm throttle body, using standard air box (possible fettling of intake to use larger diameter pipe work).

A big valve head with some cams can take you to 180 BHP too, same configuration of intake and exhaust, but seeing as you have the VVC head already I don't think it makes sense to ditch it, and the VVC ECU will cope with the increased throughput, whereas switching to big valve fixed cams head means switching ECU too. You really want to avoid that!!

Now, if you want more power you will need throttle bodies, but I reckon you'll be needing a strenghtened bottom end too, so you're talking loads more money anyway

It's tough to fit TBs to an S2 - you're going to have to cut a hole in the bulkhead for the airbox protrusion - problem is, the boot release is in the way, so you end up without a boot latch ...

Alternately try and obtain the TBs produced for the S2 Sport190 which just fit (and no more).

Cheers,
Robin

[Alex 111s]

Thanks Guys, some good pointers.
I like they fact that it improves the drivability of the engine fromlower revs.

Robin, the TB's from the S2 Sport 190, are these the same as fitted to other VHPD K series or are these unique to fit the S2? (I wouldn't want to compromise the boot space/bulkhead as I use the car alot for commuting into work in the summer so the boot gets used alot.)

[robin]

Thanks Guys, some good pointers.
I like they fact that it improves the drivability of the engine fromlower revs.

Robin, the TB's from the S2 Sport 190, are these the same as fitted to other VHPD K series or are these unique to fit the S2? (I wouldn't want to compromise the boot space/bulkhead as I use the car alot for commuting into work in the summer so the boot gets used alot.)

They're unique to the S2 Sport 190. All subsequent engines use the Toyota manifold; all prior engines used either the plastic or metal plenum (you already have the metal plenum).

Cheers,
Robin

[Shug]

Above 170 or so the engine wear is rapid and you run the risk of piston failure, especially if you plan on prolonged track usage.

Maybe so, but that's 20K on it now with the TBs (& I think you could say i used it 'in earnest') Doesn't use a drop of oil - never had a single issue. Appreciate the pistons could still fail tomorrow with no warning, but I'm happier with the VVC pistons at this stress than I ever was with the standard ones (was the valve stem seals & the liners that eventually did for that engine...)

/grasping wooden desk as I say this

[mckeann]

yes, but your never on track are you shug

[Shug]

yes, but your never on track are you shug

And having followed me on road runs, would you say that mattered

(Of course, he speaks the truth, it's not at full chat 100% of the time, but it does get used pretty well)

PS - next time I'm on track, I may use your services if you're free (swallow that pride Shug) as I'm rusty as an old rusty thing...

[Rich H]

Never heared it called pride before. Is that why you are gripping the desk so hard?

[Gaz-M]

Tut talketh some truth

Most people would only consider the TB route after going big guns on the head, but I've not chosen to do that. The engine i bought (VVC, standard) came with an Emerald dyno readout of 167 bhp on a 4-2-1 & I had the TB's & ECU anyway. Bolted on my 4-2-1, TB's and Emerald & should be in the ballpark of 185bhp (according to Dave Andrews).

Good news is that it's got bags of torque and drivability (compared to my last engine, which was a big valve standard K head) plus it's got the rush to the redline factor that the TB's give. The VVC mech is only good for 7200 & power is tailing off there with the VVC cams, so I change at 7k. I figure it's a great starting point as it's a really drivable, fast engine which isn't massively overstressed (VVC pistons & liners are graded better) When I want to go silly, I can get solid cams & convert the VVC mech (£5-600) and go for 200bhp while the pistons last. After that, a 1.9 bottom end (about £1k) will see over 220bhp. I've also got a PRT & Oil cooler to protect it a bit. The point being that the VVC head is basically the same as the VHPD head, just with extra castings for the VVC mechs.

I have a VVC engine which is going to Emerald to get mapped, internals are standard. I'll post the outcome on Sunday.

Spec is:

EU2 VVC 143 engine (Standard internals)
VHPD throttle bodies (2001)
VHPD airbox
ITG filter
340R exhaust manifold (heatwrapped)
Piper exhaust camshaft
DVA power offset timing dowels
Alpha 4.3 bar fuel pressure regulator
Bosch motorsport 6bar fuel pump
PTP lightweight flywheel
Emerald K3 ECU

Im also using a PRT and oil cooler to 'look after' things!

Im the same as Shug, im hoping to build a good high revving bottom end and go solid cam when i swap them over. Lose the nice drive but 220bhp is appealing!