Turbo Tuning

MonkeyRacing · Mar 13, 2014

I've a 1990 Turbo with stage 1 chip upgrade (under bonnet adjustable boost) & boost enhancer courtesy of Jon Mitchell.

I'm contemplating what i might be able to do to further the tuning process. I don't have an arm and a leg to spend lets say a grand maximum. What's worth looking at in terms of both bang for buck and driveability? Bear in mind unless it's fairly straight forward i won't be doing the work myself so some labour would need to be factored in. I don't fancy messing about with the boost for fear of blowing the thing up for example!

The only other non-standard parts are a K&N panel filter and Dansk back box.

JMG now offer 9xx classic performance chips and 9xx ultimate performance chips. Is classic the same as stage 1? Has anyone tried both and if so what sort of power gains are likely? Is ultimate more peaky and better suited to track use? No prices quoted on the JMG site, anyone know the cost to upgrade?

I could look at weight reduction but it's a road car and appreciate the refinements.

Any advice or thoughts much appreciated......... oh and it's already in the fastest of colours ;-)

DavidL · Mar 13, 2014

Do the suspension first, it makes far more difference to the drivability of the car than just making it faster. You can find used sets of Gaz or other adjustable and/or coilovers on ebay or here sometimes.
You have the basics done already. I'd suggest a decat but I think there are MOT issues now if it originally had one.

How much would you do yourself? S/H dual port wastegates crop up as do bailey dump valves. The D/V is a 2 min job. Wastegate is rather more involved.
Have you checked for vacuum and boost leaks?

MartinRS2K · Mar 13, 2014

I am currently selling a Bailey DV26 Dual Piston dump valve on eBay as I have just fitted a Forge re-circulating valve.

As for performance I would get it set up on a rolling road by someone reputable. I've just had my Turbo S into Wayne Schofield @ ChipWizards (based at NineMeister in Warrington) and the results have given me better power at lower revs with more mid range torque all for under £300 and no parts required.

Forgot to add that I already have a dual Port wastegate, 55lb injectors, competition fuel pump, FPR, Lindsay Exhaust System, Bigger Intercooler and a few other mods [

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If you are not close to Warrington others will be able to recommend someone locally to you who is competent at this. The technician should also be able to recommend modifications that will help increase power/drivability [

]

MonkeyRacing · Mar 13, 2014

Hi David

Suspension sorted, Koni inserts all round and about to fit some Spax front springs and lower the rear as far as possible without reindexing. I also have 968 CS anti-roll bars front & rear, 968 castor mounts and new bushes.

It's not down on power as such, no leaks as far as i'm aware. It's going for service soon so i will make sure everything is double checked. I had been looking at wastegates as the most likely next step to really make the most of the chip change. What sort of gains might i expect? Reduced lag and no tailing off boost further up the rev range i think but is there also a significant power gain? You can't get enough of boost after all! I'm not so familiar with dump valves so i'll get googling.

I'll have a crack at anything but prefer to pay the experts for more involved things that might cause expensive cock ups!

Cheers

edh · Mar 13, 2014

Dual port wastegate, MBC and chip is the best mod for the money IMO - assuming or course that everything else is working well. As David says, fresh suspension makes a big difference

T3rra · Mar 13, 2014

Chips will only raise boost, boost will like require a waste gate to keep the increase boost levels.

A cone filter may increase the spool rate which will make the car feel quicker how on a stock afm the cone filter will sit behind intercooler, at high speeds and boost the air that goes though the ic cooling the intake air will then get sucked in to the air filter and so on.

Factory air box may provide more power.

Higher boost will require
larger injectors
3 bar fpr
duel port waste gate.

There's tom ecu which uses a map set up, this will allow you to build and make changes from there without needing new chips

http://www.augmentautomotive.co.uk/

Probably the best bet

MonkeyRacing · Mar 13, 2014

Thanks for the replies chaps.

I seem to have drunk some wine & bought a Bailey DV30! I think a trip to JMG & work out on a rolling road may be in order next......

944Scott · Mar 14, 2014

ORIGINAL: MartinRS2K

I am currently selling a Bailey DV26 Dual Piston dump valve on eBay as I have just fitted a Forge re-circulating valve.

As for performance I would get it set up on a rolling road by someone reputable. I've just had my Turbo S into Wayne Schofield @ ChipWizards (based at NineMeister in Warrington) and the results have given me better power at lower revs with more mid range torque all for under £300 and no parts required.

Forgot to add that I already have a dual Port wastegate, 55lb injectors, competition fuel pump, FPR, Lindsay Exhaust System, Bigger Intercooler and a few other mods []

If you are not close to Warrington others will be able to recommend someone locally to you who is competent at this. The technician should also be able to recommend modifications that will help increase power/drivability []

Martin could you give me some info about your intercooler, im looking to fit a bigger one and any advice would be great (did you have to make modifications to make it fit)

Sorry for the hi jack.

T3rra · Mar 15, 2014

Interested as well, bigger or end tank made bigger this is known as stage 1 or 2 on stock intercooler.

Charge cooler is something that could also work, requires a small rad as well. Iv wondered if a small charge cooler could fit in place off the factory air box and work with stock ic replacing the turbo to ic pipe

Diver944 · Mar 15, 2014

With a £1000 budget I'd be going for a dual port wastegate and either a chipset to match (cheap option) or a proper rolling road setup with Wayne at Chipwizards (better option). If there is any budget leftover then 55lb injectors as well and aim for 1.2bar boost.

This is all assuming you have had a recent headgasket and all else is well with the engine and no boost leaks

944 man · Mar 15, 2014

ORIGINAL: MonkeyRacing

Thanks for the replies chaps.

I seem to have drunk some wine & bought a Bailey DV30! I think a trip to JMG & work out on a rolling road may be in order next......

Why? VTA air bypass valves don't make power - your car already has a recirculating bypass valve.

944 man · Mar 15, 2014

Id be interested to know at what sort of power a better recirculating type is required, or even a VTA, but Im confident that youre a good few horsepower short and several thousands of pounds better off.

944Scott · Mar 15, 2014

ORIGINAL: T3rra

Interested as well, bigger or end tank made bigger this is known as stage 1 or 2 on stock intercooler.

Charge cooler is something that could also work, requires a small rad as well. Iv wondered if a small charge cooler could fit in place off the factory air box and work with stock ic replacing the turbo to ic pipe

Im after a fmic that will fit without too much butchery to go under my pending vented nose panel.

T3rra · Mar 15, 2014

Vent panel don't feed as well as the duct, so even though your is maybe better air flow may not improve it.

MonkeyRacing · Mar 15, 2014

ORIGINAL: 944 man

ORIGINAL: MonkeyRacing

Thanks for the replies chaps.

I seem to have drunk some wine & bought a Bailey DV30! I think a trip to JMG & work out on a rolling road may be in order next......

Click to expand...

Why? VTA air bypass valves don't make power - your car already has a recirculating bypass valve.

To make the most of the DPW........ or at least that's my understanding from what i've read.

ChasR · Mar 16, 2014

Some people on here (and some specialists) hate the Bailey DV30s. Saying that, mine has been fine, and you do see sometimes the stock diaphragm items being ripped (indeed, I have diagnosed a couple of Turbos with knackered stock recirculation valves).

As said, DPW is probably the best bang per buck mod you can do.

In your opinion chaps, what is the highest boost one can run on stock injectors?

944 man · Mar 16, 2014

I wouldn't entertain a front mounted intercooler on a 944 Turbo. Nothing is going to work better than the original location - if you need to improve the original intercooler then so be it - I believe that the standard IC is good for 320bhp. Over that you could speak to Jon Mitchell about reworked end tanks, or even consider a Lindsey Racing modified part.

I think that you can only rate the fuel injectors on the power that they can make, rather than on boost pressure, because power is dictated by the air to fuel in the chamber rather than by the boost pressure (and from what?) which got it there, so: 275bhp-320bhp at 2.5BAR-3.0BAR.

T3rra · Mar 16, 2014

If it was me starting over, I only had grand I would do this

Buy Dpw
get it fitted by exhaust shop so it's not using adpotour plates and get a decat or center slincer removed at the same time. Mbc
£ 500

Now u can run 1.2 bar expect 300/20 hp

Delete the cv set up and replace all vacuum lines
£20

3bar fpr £ 70

Now u got £ 400 left for chips and injectors

If you Intend to slowly make changes by extra bits I would get toms ecu and map set up then move on from there

T3rra · Mar 16, 2014

Intercooler wise this is what I'm running

http://srv.augmentautomotive.co.uk/openCart/index.php?route=product/product&product_id=51

And iv duct taped up around the vent to make sure zero air can by pass it

944Scott · Mar 16, 2014

Cheers T3rra

John Mitchell mentioned that if I was going to fit the vented panel then I would be better of with a more free flowing IC (mounted in the original location) as the air may stall in front of the original.

I want the panel for aesthetic reasons and the IC is more to maintain the requirements of the car rather than add to them.