NON standard turbos and GT3 POWER

[tribetype40]

Hi,

Is anyone running a non standard turbo and or tubular manifold, 3" exhaust?

I ask as I'm fed up with the ultra laggy T3, out of date pants currently strapped to my GT3. Got whopped by a Ford Focus ST the otherday off the lights. Another turbo car but difference being it has full boost at 1800Rpm! unlike mine which comes in at around 3000, bye which time modern turbo cars are gone!

What power is out there for the 2.0lt Gt3......?

[CarlC]

Could be a couple of other factors too.

2.5l across 5 cyclinders should give better low down torque than your 2l 4pot but according to the specs of the ST the 0-60 is 6.6 seconds and these stats are normally optomistic.

Your Gt3 should have still beaten him to 60 but your only talking about approximatley 1 sec difference. Im suprised you got whipped.

I take it your happy your car is boosting and overboosting correctly and your chargecooler is fully operational ?

Our turbos may be old but they should still be able to pull your head off if correctly setup. It has taken me ages to get my going properly but once the turbo and wastegate is correct our Esprits are little rockets.

[SteveSmith]

I think the problem that Doug is referring to is that initial lack of power before the turbo kicks in. Certainly makes the car feel sedate when pulling away from lights.

But then charging away from lights is best left to the chavs in their Corsas and Saxos.

There's ways and means of driving around the lack of low down torque - McDave certainly didn't seem to have a problem with it and remember, it is already one of the fastest GT3s on the road and I don't believe there were many cars that overtook Dave.

It needs to be driven like an Esprit NOT a modern turbo'd car. There's a simple answer to wanting to drive a car like a modern turbo'd car....

Just my 2p worth but I wouldn't swap the lag for the world - reminds me I'm driving an Esprit

[tribetype40]

dont get me wrong, the does shift it just takes ages (relatively speaking) to get going. by that time the st was already a good 4-5 car lengths in front. It was then level pegging untill we got to a fair pace. It was only after that that I started to make up ground.

[CarlC]

As a simple and cheaper alternative have you considered chipping your GT3?

From the reviews I've read the chips can make a significant difference and also bring in boost much earlier an provide higher boost levels sooner too.

Couple with decat - sports exhaust - K&N filter - Ram Air to get the best effect which you should do anyway if your thinking about an uprated turbo.

But if you do go down the new turbo route keep us posted on your progress. There have been a number of threads already on replacement turbo's for teh 4Pots if you do a quick search. B)

Right, Im off to find an ST to take on to settle the score.

[chris]

I reckon the problem you had mate is the same the manufactures face, You reeled the focus in as your turbo runs alot higher pressure at max chat whereas his comes in lower. Only answer is really twin turbo system which is best of both worlds but not sure how expensive to set up. Alternatively as you have the GT3 could you not tune and remap your car to be more responsive on the n/a side of things and then let the boost take care of itself. Failing that rev its face off, jump off the clutch and fly off the lights in a cloud of smoke. The biggest problem with that method is you have to win as everyone and their dog is now watching! lol. Dont worry to much about the chav thing as i'm told lotus' dont count. Let us know how you get on though mate it would be interesting to see what can actually be done.

[docf]

alot of factors at play here.. weak clunky gearbox so no neutral drops or power shifts, "safe" boost maps which dont allow real boost below ~5k rpm, overly complex intake and exhaust.. etc.

Keep in mind that changing out the turbo is no small task.. took me quite a few hours and was tricky to dial in without access to a dyno or wide band o2. I would start out with just a performance air filter, ram air mod, free flow exhaust. second stage add a performance chip, the "high torque" chips allow more boost at lower rpms and will give you the most of what you are looking for. In addition to the chip add high performance ignition coil packs, a new set of plugs & wires and a blow off valve. so far here you are looking at maybe $2000 in parts if you go for a fancy exhaust and $1500 if you use an off the shelf muffler and have a shop fab up the plumbing.

if you still need more power you can upgrade the turbo but keep in mind a 2.0 motor will become even laggier if you overdo it. I had my turbo rebuilt to t3 super 60 spec and also added a blitz boost controller and plumbed the ac condensor into the chargecooling system for a little more cooling capacity and a little more weight over the front wheels. You'll also need to make fuel system mods at this pont.. i found that a good set of balanced injectors, a high flow pump and a high flow filter made a hige difference in top end power especially under high (16+psi) boost. Assuming you have your old turbo rebuilt and modified as i did and do 100% of the labor yourself this will set you back another $2000. Hope to get it on a dyno and do some more with the fuel system this winter but i cant imagine having more power at this point without doing serious damage to motor/trans or my insurance rates.

[Advantage]

Don't be fooled into thinking that a re-chip will be the end of your off boost lag. I run a Puk no.11 chip (along with the other usual mods mentioned above) and frankly, I'm underwhelmed. Yes, there's a touch more (seat of the pants) power at high rpm but there's still absolutely no power when just chugging around town.

You all know the scenario, getting to a roundabout and do a rolling 2nd gear pull-away. A normal 2ltr Mondeo would cope with this but not a 4cyl injected Esprit. I'm not expecting neck snapping acceleration, but I would like the car not to stumble over a flat spot the size of Holland almost to the point of stalling - while the car is rolling! The only solution seems to be to dip the clutch and try again. This trait is present as standard and in modified form and I absolutely detest it. There's just no need for such poor mapping.

I don't know what the next step would be (apart from a V8! ). Certainly not bolting on another (potentially more laggy) turbo. Maybe a different management system such as an Emerald?

Top end high rpm (6/7000 rpm) power is easy and cheap to get. Low end (1200-2500rpm) torque for some reason seems to be particularly elusive for this engine, which is a shame as that's where in 'the real world' the engine spends most of it's operating life.

[Jonathan]

You got dropped by a Focus ST ?

Did you have the hand brake on still ?

ALL Esprits are temp dependant btw, when the coolant is below a certain value the overboost feature will not work and you will be limited to 0.65 bar boost, this can often be mistaken for performance probs.

A Golf VR6 tried it on with me sneaking past the other day and caught me in the wrong gear - quick change to 3rd saw him as a tiny dot in the rear view, if I had done that in 4th might have been a different prob.

Never forget the EVO 6 vs Focus on top gear and they showed the turbo lag on the car in compariosn and the basic focus skinned it

The GT3 is heavily RPM dependant, anything under 3500-4000 and you're missing out - play to at least 7500 before changing up, believe me it's your driving - Dave used to keep up with performance bikes in that thing, I was under the impression it had a hybrid turbo already fitted ?

Thats all I can suggest - new turbo but the lower capacity is always going to give you low end torque problems, if you solve that with a compressor then you suffer top end RPM.

[Loose Cannon]

Same problem, and a chip makes no odds at low rpm. This was one just of the things I would have like to questioned Brian Angus and the gang about if we had more time. Like why do my revs actually drop when first touching the accelerator?

[CarlC]

Very interesting to see the differing views on our cars performace on this thread.

Personally I have no complaints about low rpm torque becuase thats not what our little 4pot engines are about. As John says our engines are high revving. I dont expect to roll up to a round in second and then try and boot it off from low RPM. You need to drive the 910 through the gears. It was interesting to hear Mike Rings comparison between his old GT3 and his new S350 early this year at donnington meet. As I expect the v8 pulls very low down in the range were as the the gt3 needs driving and getting the revs in the mid to high range.

I have to say if it wasnt for a problem on my car that caused an overboost issue and showed me what the car was truly capable of I probably would not have spent a bloodly long time getting my boost right. The boost pressure pipe to the wastegate capsule had split, bleeding off pressure. I'd just taken the car out after some extensive work and was taking my time driving steady to ensure everything was running right. After a few minutes joining a motor slip road a porka came past me and I just couldnt resist putting my foot down. The boost came on so fast and so hard I literally strained my neck it went back so fast. I scared the sh1t out of myself and backed off until I got more used it the power. On returning home I spotted the overboost problem and fixed the leak but it took an age to sort out my lack of boost. But Im thankful I got to see what the car could do if it was setup correctly.

Now its all ...

Edited October 12, 2006 by CarlC

[Jonathan]

Mark - would have thought you have the same prob as me with the exhaust.

With large exit areas you're messing with the exhaust gas as it exits, not so bad at 2000rpm + but at idle the car is litterally pulsing gas through the tubes.

Becuase the pulses are not exiting at the right speed for the rest of the system becuase of more exit area the car can experience blips of back pressure which stall the engine briefly - idealy they should be tuned to the manifold and very few aftermarket components are to any extent, indeed my Elise has a restrictor on 1 of the pipes in order to control the back pressure at low revs.

Mine stutters a lot at idle and pops on lift off for this very reason, going to get it fully reconned soon, tuned and possibly ported as I really don't want to compramise on the sound of mine - perhaps raise the idle a bit ? Wrap the manifold is another possibility to keep the gas hot as possible and a fast exit.

[Advantage]

I dont expect to roll up to a round in second and then try and boot it off from low RPM. You need to drive the 910 through the gears.

I wasn't implying that I was trying to boot it from low rpm, just driving normally. A normal saloon/hatchback can cope with small throttle openings when at low rpm, why can't a car that's been designed by some of the best engineers handle gentle acceleration? An Elise has excellent throttle response.

Go and start your engine. Once it's warmed up, touch your foot on the throttle pedal. What's the first thing that happens to the rpm? Up or down?

Drive along slowly in second gear, lift off the throttle then gently reapply. BANG! Someone's turned the engine back on again.

The Esprit 4 cyl is an ok device for going fast, but for some reason it's pants at going slowly. How is it that Mitsubishi etc get 300+ bhp from a simple 4cyl yet still retain driveability, and the company that designs engines for other manufacturers can't?

[docf]

Go and start your engine. Once it's warmed up, touch your foot on the throttle pedal. What's the first thing that happens to the rpm? Up or down?

Drive along slowly in second gear, lift off the throttle then gently reapply. BANG! Someone's turned the engine back on again.

my car does not do this. It did for a brief period but it went away when i started changing stuff and never came back. I think what helped the most were the ignition coils and upgrading to the #2 chip... but i cant really single out the 1 thing that made it go away.

[esprithk]

hmm...my High-wing is stock. and I can pick up speed very quick. I think one needs to pay attention to keep certain rpm in slow drive and then accelerate (remember it is a high-rev car, kind of like a HONDA VTEC)

**anyway, I don't know what is a Focus ST, but that name sounds bad enough

[Dermot]

If anyone is having poor throttle response the first thing I would look at is the TPS (throttle position sensor).

This can go bad in a number of ways, eg. the TPS needs to return 0.65V-0.7 V at zero throttle openning. This is an important calibration point. The TPS should return a linear voltage output as a function of throttle opening angle, if it is not linear and/or variable you will get terrible driveability. All this info is recorded in a Freescan log and I check all these and other TPS issues when people send me log files.

RPM dropping when you press the throttle can be investigated by plotting TPS against RPM from the log file data.

Dermot

[Loose Cannon]

**anyway, I don't know what is a Focus ST, but that name sounds bad enough

If they ever bring out a hi-po diesel version it will be the Focus STD