Stage 4 Turbo Setup

[muffdan]

Hi all,

It's about time I wrote up on this project of mine for those interested in their turbo'd '2s.

First a quick history. I've owned my '2 for about 4 and a half years. Got the TTE turbo and the full SP exhaust system Christmas 2006 (thanks santa). Then got myself the SP240 back in February this year and had plans for uprating the internals this Christmas (oh santa you are good) so that I could crank up the boost.

However, during the Southern Softies fun run this summer I went and blew my head gasket   s:( s:(  . Rather than pay for that to be repaired now, I decided to get the engine rebuilt while they were at it. It turned out to be a good desicion as my bores had ovaled.

So, I had the engine rebuilt by Matt over at SP and it now comprises of the following components:

TTE turbo kit + uprated intercooler
Unichip
AEM boost controller
Crower Stage II FI cams
Crower Connecting Rods
Wiseco Pistons 8.8:1 compression
Darton Sleeves
MWR valve set
MWR ARP main/head stud kit
Toga oil pump
2ZZ water pump
Oil cooler + front mounted radiator
MWR 630cc injectors
SP exhaust system + down pipe
Fuel pressure reguator
Induction kit

The engine was run in and went off a few weeks ago to a dastek dealer to be mapped and for various reasons its taken them two weeks thus far to sort. Partly password complications with my existing unichip, partly I-don't-know. Boost has been turned up to 15 psi and the ponies have been counted at a jaw dropping 210 bhp   s:shock: :shock: s:shock:  Actually, that's not jaw dropping at all as I've lost 30 horses. Not good. Matt is going to pop over to them on Thursday and figure out where they've gone wrong or inform them their dyno's broken!

Expectations are between 320 and 360 bhp depending on what that tiny TTE turbo can sustain psi wise at the higher revs. I might have to get santa to provide a GT28 for Christmas this year.

The plan is for Matt to put this or something similar together as an SP Stage 3 option for a fixed price as they do with the basic TTET and SP240 packages. There's probably plenty of tweaking left to do with my car first though to get the drivability sorted. I might opt for a variable boost controller to feed the torque in smoother.

I'll update the thread on Thursday with the actual bhp achieved and post up the dyno plots when I get them.

Jason

[markiii]

well if 12psi on standard comp pistons get 270bhp I wonderi your going to need to run more than 15PSI with 8:8:1 pistons?

[Tem]

well if 12psi on standard comp pistons get 270bhp I wonderi your going to need to run more than 15PSI with 8:8:1 pistons?

Compression shouldn't affect that much. Going from 10.1:1 to 8.8:1 should only lose some 3-5%. Say he lost 5% and it would be ~255hp. After that the increase from 12psi to 15psi should be some +10%, roughly 280hp. The cams should make out even more.


Of course these are all very rough values, but should give some idea. I assume they retuned for the new engine? I'd like to blame the Unichip first, it has been known to have issues with bigger mods.  s:( s:(

[SteveJ]

well if 12psi on standard comp pistons get 270bhp I wonderi your going to need to run more than 15PSI with 8:8:1 pistons?

At a guess I would say the valves arent opening wide enough or for long enough for the charge to get into the pots. I'm not sure where the TTE measures it's boost pressure from - is it pre or post TB? Either way you are measuring the pressure outside the pots and the 8.8 pistons effectively increase the charge volume (but not the displacement) so there is a significantly larger volume of air trying to get into the engine.

[markiii]

well as I said to muffdan previously I tend to agree, that spec engine deserves a standalone ECU, certainly I'm amazed the unichip can cope with that size injectors

[muffdan]

The large injector problem with the stock ecu is worked around by the fuel pressure regulator. The fuel pressure is reduced to below stock pressure for idling and increased (to way above stock) when on boost. Perhaps this work-around isn't going to work out and I will end up with a stand alone ECU.

The boost pressure is going to get turned up to the maximum the turbo can deliver, then turned back down to give a torque curve that keeps the car drivable. 15psi is the starting point, not sure what it'll end up at. Before the rebuild I was generating 240bhp at 9.7psi

Steve, I'm not sure where the boost pressure is read from.

Jason

[ChrisGB]

A couple of things spring to mind. First, is the TTET turbo used capable of high boost at high RPM (where the big airflows and power numbers come)? Second, do you have AFR and boost plots, because they should show any loss of boost or wrong fuelling, making it easy enough to diagnose where and why they are having problems.

Chris

[muffdan]

I've not heard back from SP yet on how it went yesterday but I'm chasing Matt for an update.

What the turbo can deliver is definitely a potential issue, but according to the mapping garage it's generating 70% more PSI at high revs than it was under the SP240 setup. Considering the SP240 delivers 240 BHP, this boost increase should more than compensate for the lower compression of the pistons and be delivering a lot more than 210 BHP. It does look like the turbo is going to be the bottleneck for the final figures whatever they turn out to be though so I'm going to start looking for a bolt-on replacement.

What I can't understand is how the boost guage can be reading a 70% higher PSI and that not translate into more BHP! Perhaps there's a boost leak.

Unfortunately all this is happening a long way from me and SP are the middle man, I'm not dealing directly with the mapping garage. This is a negative because I'm not 100% in the loop and I haven't seen any sort of plots, but it's a positive in that Matt is now working with the garage to sort this out for me.

Jason

[markiii]

you can have as much boost as you like, if teh fuelling map isn't right you won;t get any power at all

[ChrisGB]

Worth checking the FPR is doing it's thing. If it is not, the boost increase actually reduces fuel throughput. An AFR trace will tell lots.

Chris

[muffdan]

you can have as much boost as you like, if the fuelling map isn't right you won't get any power at all

You're right Mark, I'm told the AFR is good but I'm taking it all with a pinch of salt. The maths just isn't adding up here so something must have been overlooked or be is being read/interpretted wrong somewhere.

... Just spoke to Matt on the phone, the guy at the garage had a personal issue to deal with yesteday and had to postpone the mapping session to this afternoon. Hopefully Matt will get to the bottom of this by the end of the day.

Jason

[muffdan]

Update.

Just spoke to Matt. He thinks the problem is the spring in the waste gate isn't stiff enough. Just got to order a new one and then it looks like I'm good to go!

Jason

[uktotty]

Keep us updated Jason as this should be a beast but is not being beastly right now

[Chris]

Sounds like you'll have a stonkingly fast motor after it's all done, even more so that the already impressive sp240!   s8) s8)  

Do you know why the head gasket went - there are cars running more, so is it a flaw the the ttet kit somewhere?

Slightly worrying that you survived 4.5 yrs without boost but only just over a year with the ttet and then just under a year with the sp240 - here's hoping i don't get boost addiction that bad!!   s:lol: :lol: s:lol:

[muffdan]

A few years ago I had an engine rebuild. The garage that did the job didn't put all the bits back on right and a belt pulley fell off whilst I was going along! The water pump stopped turning and the car overheated whilst I was finding somewhere to pull over and have a look at why my battery light had come on. That did the damage as it needed the water topping up every 2000 miles or so after that. MWR use the stock Toyota gasket on their 500+ HP car so I wouldn't worry about yours going pop Chris.

I should be collecting my car later today so should have some figures then, although they are still questionably low   s:( s:(   I'll be interested in some passenger rides at Angelsey next weekend to compare mine with some other kits!

Jason

[loadswine]

Well you know how yours compared with mine on the Corfu run Jason, so that may give you a bit of a yardstick.

[muffdan]

Ok, having collected the car and driven it 80 miles already I am pleased with the results despite the disappointing BHP figures below. The car pulls very hard when that torque kicks in but is still very drivable around town. There is work to be done to hit the horse power figures I'm after and a puzzle to figure out as to why the power curve is so flat! Our best guess is the turbo's too small for the FI cams 8.8:1 pistons, resulting in the lower power rating over the SP240 I started with. Anyone got any better ideas?!   s:) s:)  

Official figures are:

Torque: 260 ftlb @ 3900 rpm
Power: 225BHP @ 5700 rpm
POWER

TORQUE

BOOST

[ChrisGB]

To my eyes, it looks like the turbo is maxed out for flow. There is a very linear fall off of torque and boost from the peak numbers. I do not think the FI cams or LC pistons would have much to do with it. The LC pistons allow the big peak in torque to be obtained, but then the turbo seems unable to supply the volume of air needed as the revs (and thus the requirement for flow) rises. Boost seems to roughly halve as RPM demands roughly double the airflow.

Do you have AFR and advance plots also? It could be possible that the engine is unable to supply the fuelling (maxed MAF or injectors or fuel pressure limiting) but these problems could produce some pretty erratic curves.

Chris

[muffdan]

thanks for the input Chris, much appreciated. I don't have any other plots unfortunately but I'm told the AFR is good. I did hear knock earlier so I'm going to have to get the map looked at again. The turbo I have was producing 240BHP with my old cams and pistons, with a slightly lower psi at the red line.

Jason

[markiii]

from memory its a T3 turbo so should be able to flow as much as a GT28R whihc is good for around 300bhp

[muffdan]

I believe it's a T2 Mark but I might be mistaken.

Jason

[ChrisGB]

thanks for the input Chris, much appreciated. I don't have any other plots unfortunately but I'm told the AFR is good. I did hear knock earlier so I'm going to have to get the map looked at again. The turbo I have was producing 240BHP with my old cams and pistons, with a slightly lower psi at the red line.

Jason

The drop in peak power over the old setup may be a result of the LC pistons I suppose.

Any idea what RPM you were seeing knock at? Around peak boost / torque I would guess?

Chris

[muffdan]

There was knock from 4k through to 6. It wasn't happening initially, took about 60 miles of driving before it started.

Jason

[muffdan]

Update:

After it became evident last week that the turbo was in bad shape it has been taken off and is currently being refurbed by Turbo Dynamics with a larger compressor. Somehow the existing compressor blades got very badly chipped. Once its back and fitted it'll get shoved on the dyno once again. If it's not what I want it to be still I'll be upgrading to a GT28RS. Matt said he will buy my existing turbo off me at the refurb price if I do replace it with a bigger turbo making it worth a punt with the refurb.

Jason

[loadswine]

That's a pretty positive approach, hope it gives what you're after mate.