hmhaga

First, take a look at this track day video: Click!

I have a MY98 wagon with H&S turboback, TurboXS at 1.1 bar and a Prodrive PPP Ecu. I'm very pleased with the handling on track days now, with DCCD and numerous Whiteline parts. I can keep up with most cars when cornering, but as you can see from the video, I really miss some straight line acceleration - barely managing to pass a Lotus Elise in the end (I hate that! ). The stock TD04 turbo runs out of puff above 5500 rpm - which is also a problem with the short 6MT JDM gearing.

Mileage is at 180.000 km and being a 98-model, spending a lot of money on this engine to remap, fit bigger injectors etc is out of the question (it'll be replaced with an STI engine when it dies).

So, is it possible to fit a larger turbo that can be run safely with the stock setup. I'm thinking of a TD05 Front entry, or a TD04 hybrid. Any input appreciated.

New_scooby_04

iTrader: (4)

In a word mate, no!

At the very best, you won't be getting the best out of the turbo, at the worst, you'll break something expensive...ie. your engine! A TD05 mapped to its potential -even a 16g one- will also quite happily deliver the kiss of death to your gearbox.

I'd be looking at a TD04 hybrid or one of the VF series from an Sti of the same year and a chat with someone like Andy F about an Apexi Power FC ECu and remap.

Ns04

Maz

iTrader: (34)

Hmmm I am nearly sure that a while back Jap Innovations were running larger turbos on stock ecu settings. Infact if I am not mistaken they had a series Mcrae running 340 bhp with just a front mount and mrt boost controller and that was with 380cc injectors! Rich Wild himself was running over 360 bhp and I think that was without aftermarket engine management.

maz

andypugh2000

In a word mate YES!!! you can easily run a bigger turbo without remap etc on stock injectors too.

As long as you have a UK car (ecu) then it will not be a problem. I currently run a UK MY98 turbo with full decat, VF28 turbo Induction kit (K&N) and a electronic boost controller set at 1.25 bar, it ran 312 bhp at PE and 298 at SRR

Been running this setup for 30k now and just turned 100k

AP

New_scooby_04

iTrader: (4)

Guys, this is a car with 180,000 kms already on the clock and it's being tracked fairly regularly by the sounds of it. You're really telling him its a good idea for him to fit a bigger turbo to it without appropriate mapping, no one's even mentioned an uprated fuel pump, knocklink or AFR gauge. The guy said he didn't want to splash out lots of money, so taking risks seems inadvisable. Like I said, on the std map, at the very least you won't be getting the most out of the new turbo.

Let me be clear about this, I'm NOT an expert, but this -to me- has bad news written all over it!

I'd seriously consider consulting a reputable mapper about this!

Ns04

andypugh2000

The only person to do well out of re-mapping a car with these mods would be the mapper, of course they are going to tell you its necessary, just like the planks in currys that advise you to take out an extended 5 year warranty for 9.99 on a 25 quid kettle

Mapping is not necessary unless you are talking large turbo's and i do mean large.

My car has been dyno tested 3 times now with these mods and the AFR's are spot bollock, Mine also ran 2 bhp behind a mapped P1 with more or less the same mods except boost pressure.

AP

scoobfan

Sorry guy's, i'm with Ns04 on this one.

Running a larger turbo is going to mean more air and a leaner mixture,
your going to be fine at the lower end but once the engine comes on boost
I think you could be looking at a melted piston.

The fuel maps will need adjusting.

Rob

Maz

iTrader: (34)

Hmmm .....I quote the dyno operators comments when running aforementioned series Mcrae, 'the car ran quite lean off boost but poured plenty of fuel in when on boost'....This series Mcrae was getting a reliable 340 bhp with stock ecu and (380cc) injector set up. As long as the AFR is okay a remap is not absolutely necessary. As I have said Jap Innovations did it with SEVERAL cars so were they wrong??!! Hopefully Rich or Andrew Conway owner of the said Mcrae may be around to set the record straight.

scooby-tc

iTrader: (2)

380cc injectors would have maxed out long before 340bhp even 440s struggle with that power.In short if you add a bigger turbo it will be sucking more air into the engine and not compensating it with fuel causing it to run lean on boost.Best option to you is to PM Bob Rawle or Andy F or one of the well known tuners on this site and ask for their opinion.Personally i think if you add a bigger turbo and dont get a remap you will be looking for a new engine quicker than you think

john banks

I would fit a Walbro pump for £80 simply because of the mileage on the car, and fit a knocklink. Then use your bigger turbo of choice with a manual boost controller - eg Dawes. Check the fuelling with a wideband AFR. If you get knock, increase the octane - NF works well, or Millers CVL turbo.

I would actually use a standard ECU and a fuel cut defender (zener diode will do) as they run less timing than the Prodrive ECUs - this will suit the bigger turbo better.

Ignoring the strength of the gearbox for a moment...

The engine you sound happy to replace - I would kick it with 1.6 bar in the midrange and let it taper at the top by adjusting the actuator - on a TD05 then 1.25 bar at the top is sensible. If you run out of fuel at the top then turn up the fuel pressure - increase is the square root of the ratios of fuel pressure - so 4 bar relative instead of 3 bar stock will make the 380s behave like 440s. Closed loop should still sort the idle and cruise out OK.

Even on your stock TD04, with at least a knocklink I'd get the boost up to 1.6 bar in the midrange. You should not run out of fuel by kicking up the midrange as long as the pump, injectors, regulator and MAF are all OK.

Maz

iTrader: (34)

The dyno run was done at G Force while Chris Davies was there they may have the details on record, definetely running 380cc's. whilst not in any way questioning either Bob's or Andy's integrity asking a mapper if mapping is needed is a bit of a cop out.

Maz

iTrader: (34)

Thank you John!

thedeester1

Was the elise standard? Ive seen one at 300bhp that would destroy most cars with twice the bhp. The Elise weighs about as much as a sack of potatoes!
The top speed of that Elise was about 130MPH but the power and the gearing got it there FASSSST!

hmhaga

Thanks! I already have a Walbro fuelpump, as the old one died/fried trying to supply enough fuel running on rally stud tires (picture).

I have been reading Rich Wilde's thread carefully, as well as John Banks' posts back in the days of zener diodes - and numerous other threads where people have replaced their turbos and run with a stock ECU. As it seems, it is the gearbox that dies first My old 5MT is already dead and replaced with a 6MT, so at least one problem is eliminated.

I do know that a remap is required to utilize the full potential of a larger turbo, but being a model year too early for EcuTek makes it too expensive - considering the mileage of the engine. It could die at the first track day even with a remap.

The Elise has 105 bhp at the wheels. I could have passed it, but it would have been too close to the corner entry - and the driver wasn't exactly paying attention to his rear view mirrors. Therefore, I need more power to pass cars earlier down the straights

silent running

Well IMHO people make too much fuss about big turbos making you run lean etc. In fact if you trawl around on here enough, just about anything you could do to your Scoob will make it 'run lean'. As someone else mentioned, unless you are running a huge sized turbo and don't bother to control the boost, you won't have a problem. Bottom line is a turbo is simply a mechanical device for compressing air. The ECU knows how much air its drawing in just the same as it would for a TD04. The characteristics of say a VF35 (which I swapped my TD04 for) aren't hugely different from a TD04 or any smallish turbo TBH.

I think the problem, and the horror stories of 'running lean' must come from people who whacked on a much bigger turbo, let it overboost and then broke their engine. Why anyone would do that I don't know. It seems pretty simple to me...

1. Fit your new turbo
2. Run it very briefly with the standard boost solenoid and see how it boosts. You'll soon know exactly what the response is like.
3. Bring your max boost level down to where the old TD04 would normally get to by fiddling your boost solenoid plumbing. Either use a manual boost controller, or by drilling out the restrictor a little, or by using a 3 port solenoid instead of a 2. You could even be extra cautious and simply take the restrictor out of the plumbing which will get you down to just over the wastegate pressure.
4. Enjoy your totally safe boost level from your new turbo until you decide to rebuild your engine or get something like an Apexi Power FC in and have it mapped up properly.

All IMHO of course.

Andy.F

One thing to be aware of is the factory tolerances can stack up either in your favour or against you. Thats why some get away with it and some don't.
As JB stated earlier, as long as you monitor the AFR, listen for det and take the appropriate action then you should be fine.
FWIW after tuning cars on std ECU's, Rich Wild and many of Jap Innovations customers went for the Apexi Power FC and their findings with regard to the spread of power and response, (not just the peak power) were documented on here some time ago.
Second thing to be aware of is something that you get away with on a 98 UK car may not apply to a 99 or new age car. As the model years progressed the ECU's became more complex and certain parameters such as knock control may have upper load limits after which the ECU just doesn't listen for knock anymore !
Third thing (and I could go on all day ) is that something as simple as a replacement filter or decat exhaust could be enough to destroy the engine in some models.
Not scare mongering but just recommending an AFR and Detonation check after any diy mods.

Andy

andypugh2000

Point taken Andy, maybe I am just one of the lucky ones

Deos anyone have a link to rich wild's thread about this as I would like to read up on it,

Cheers

AP

Andy.F

Here's one of them
http://bbs.scoobynet.co.uk/showthrea...37#post4347737