Modifications, budgets and a lot of questions...

[Paul 442]

Hi everyone,

 

I've been thinking of buying a GT86 for a while and getting a few modifications done, but some of the specifics around each are really confusing me. Since there's quite a few people on this forum who have made modifications to their cards I was wondering if you could bring some expertise to bear:

 

Wheels

 

I really like the look of the Rota RT5s but on Rotashop they don't come up as being compatible when I select the car. I'm assuming this is something to do with the 5x114 measure of thee wheels with the 5x100 measurement on the car? I'm assuming those are the measurements for the the holes the bolts go through to secure wheel to axle? I can find them in 5x100 as well but only from the States?

 

Also I see a lot of discussion around square vs staggered setups, I only plan to use the car on the road and really prefer the look of a staggered setup, is that going to cause any issues and do I need to worry about any additional costs like spacers etc? Also in terms of tyres I've just plucked them straight from the ft86 thread, 225/40/18 and 255/35/18 sound about right for 18/8.5/ & 18/9.5?

 

A bit like these:

 

 

Exhaust

Having test driven a GT86 recently the sound...well it was less than impressive (I used to ride bikes). Firstly, can I just remove whatever it is that pumps that tinny sound into the cabin?

 

Secondly, I will be looking to get a Stage 2 turbo at some point, so I should go straight for a 3" exhaust right? The ones they sell on Fensport are full systems, I assume I can get the whole thing fitted to a stock car with no bother? Do I need to worry about motorway drone, should i go for a resonated centre pipe?

 

Lowering springs

As I don't plan on racing the car will lowering springs alone be ok for road use? I only want to drop the car about 25mm at this stage, if I wanted to drop it further coilovers are probably a decent bet somewhere down the line?

 

Induction kits

Quite simply, are they worth the performance increase as a "quick win" pre-turbo? At ~£300 they seem pretty reasonable, what sort of bump can I expect?

 

Other

And on top of all that, fitting and a remap etc etc.

 

Basically if I had about ~£5k to spend on a stock GT86 where would the money be best spent assuming I've driven the stock car and it needs a bit of a power increase, larger wheels and a bit more noise?

 

Help much appreciated.

[Lauren 2259]

Wheels: 

 

It's fine to run a staggered setup, but you will increase understeer. Depends what you want of course. 

 

Those tyre sizes will work on the wheel setup you have suggested. 

 

5x100 is an awkward size so availability for wheels can be an issue. Obviously allow for VAT and shipping etc if you import from the US. 

 

Exhaust:

 

You can remove or plug off the sound generator, that is no problem. 

 

If you're going to for a high power turbo, 3" will be better. 

 

Exhaust options vary in terms of loudness, there are lots of available. Do your research, come to meets and hear others' exhausts for comparison. A turbo will quieten the exhaust. 

 

Lowering Springs:

 

They will do the job fine. Coilovers are a better option but obviously more expensive. 

 

Induction Kits:

 

It changes the sound but doesn't have much of an effect on power really. 

 

Other:

A remap is around £500. 

 

People modify their car to their own tastes. There are plenty of members around who have done the mods you have asked about. Come to some meets and find out.

[Paul 442]

Cheers for the quick reply Lauren! I'm getting the Wheeldude guys (found them from the ft86 forum) to price up the cost of importing from the States, since buying them in the UK and getting spacers (and not even getting the colour I want) is going to cost ~£1600 if I can get a similar price from the States and get exactly what I need that seems to be the better option.

 

Thanks also for the info on the induction kit, will save money and put towards the turbo.

[Jamie_GRMN 177]

Welcome to the club,

On the mods front I used roughly the same budget (including the fitting) minus the map, all the rest was pre bought... To manage this:

Wheels are Compomotive MO5.s in 17 x 7.5

Suspension is BC BR coil overs lowered 40mm+ Plus whiteline bushes and roll centre adjusters etc

Exhaust is a custom made single exit from the overpipe back (overpipe is cobra)

Intake is a k&n filter plus Samco pipe with generator delete

[Church 209]

Lauren: not just acceleration grip balance to more understeer-y. Braking will be affected as well. As chap will go turbo, probably nothing wrong with too wide tires .. but i still advise to keep square setup.

I'm not sure it's worth to pay for 3". Weren't people running upto 400hp even on 2.5" just fine? Though i guess some aftermarket catback exhaust will be bought anyway, if stock sound seems that bad, and one can choose 3" at same time. Same for intake upgrades. Stock airbox is not that bad, most often most of intake gains can be got just from $40 worth aftermarket air filter.

As car is mostly for daily driving, not track .. maybe worth to consider some comfort upgrades too? For example - armrest, reverse camera, audio upgrades? For daily driving i wouldn't consider any lowering too, unless one drives only on roads like in Japan . Though if looks are that much more important then practicality .. everyone has his own taste/preferences, it's your money after all .

[S18 RSG 429]

I'm in a similar situation myself at the moment.

 

Like you OP, I wanted staggered setup Rota's, but ended up settling for 8.5" all round. The extra inch on the back isn't really gonna make that much difference to looks, and for the downsides it has on handling, it's really not worth it. Plus, as Church mentioned when I asked the same question, square setup means you can rotate tyres if you even need to, which is a nice addition.

 

I would definitely recommend a few comfort based upgrades for a DD. Armrest is a must. Can be picked up for £100 on eBay, and takes about 20-30 minutes to fit, but transforms my daily commute. I also invested time into fixing some of the well known rattles (the plugs in the boot, the hook behind the rear seats etc.), this may not be an issue for you, but it makes me enjoy the car a lot more. There's a good thread on it somewhere, just search "The Rattles thread" on google, I'm sure you'll find it.

 

I too am only in the market for springs, but I'm going for a 35mm drop. 35mm drop on 18" wheels seems to be about the perfect height, and probably where I would set coilovers, so I see no point spending the extra on coilovers for my daily. I will just be complimenting the springs with some uprated bushes, roll bars etc. as has been recommended to me by multiple site sponsors on this site, and some more experienced GT86 owners over on the FT86 forum.

 

In terms of exhaust, there was nothing I fancied on the aftermarket scene, so I'm going for a custom system. 2.5" manifold back system with a 2nd cat delete. 2.5" seems to be good for low 300's in terms of hp, so when I get around to getting mine supercharged, I would think 2.5" should be enough for a mild supercharger setup.

 

Ignoring the supercharger, I would think you can quite easily get the car looking better with suspension and wheels, and driving better with a few engine upgrades, exhaust and remap, for around £2.5-3k, or possibly cheaper if you shop around.

 

HTH.

[Sonic 4]

agree about the intake kits none of them do anything, apart from increase intake noise

 

just fit a decent filter in the stock airbox and you'll get the benefit

couple it with a re-map and you'll get quite  a lot of bang for your buck

[Ade 517]

Some of the induction kits can give you a bit more power simply because they mess with MAF sensor, giving the ECU incorrect airflow data. Usually the result is a leaner running engine. With a tune correcting for this, it negates any benefit. Air filter and be done. Cossy one is £32.

 

Regarding lowering springs, generally there are two types: performance biased or Comfort biased.

 

The performance biased springs tend to be a smaller drop and are working in the linear region once the weight of the car is sitting on them. Linear give a more predictable feel. The progressive parts of these springs are there simply to provide lowering and make sure the spring stays in the perch at full droop. Examples are Eibach USA springs (fensport sell these, 3.6kg front and 4.9kg rear) and RCE yellows 4.5kg front and back. Both these come with shortend bumpstops too as they are a must really. Stock struts come with big progressive bumpstops.

 

Comfort biased lowering springs are usually too soft, resulting in hitting the bump stops during performance driving on rough roads and tend to be sitting in the progressive region of the spring under the weight of the car and get firmer very quickly as they approach full compression. Examples are Eibach Europe springs or Tein Comfort.

 

FWIW the front dampers have too much rebound damping for rough surfaces so a bit more spring rate at the front is beneficial.

[Paul 442]

I thought it might be worth updating this thread rather than starting a new one....

I am currently still sans GT86. A lot changed for me in the past 18 months including getting married and buying a house, however the plan is for me to buy one around March next year, preferably a white one, as the last "boys toy" before the wife starts pestering me for kids.

In preparation for getting the car I've already been getting hold of some of the bits and pieces. So far I have winging it's way to me:

• Auto-fold mirror system
• TRD-style ducktail spoiler
• Rota RT5 18x8.5/9.5
• Centre armrest

I decided to go the whole hog and get coilovers to start with, so I've chosen to go for the Tein Flex Z (which have been recommended by several users). I also know that I want to get a new panel air filter and a remap, but I confess I'm struggling to get my head around all the options when it comes to replacing the exhaust.

So I really like the look and sound of the Injen system:

http://www.fensport.co.uk/Parts/Model_108/Category_4/4472

My understanding is that as a "Cat Back" system, it bolts into the "over pipe", which in turn bolts into the manifold? And that to pass the MOT at least 1 of those parts should contain a catalyser? I figure that as it's likely to be a while before I can afford to add a turbo I should look to get the manifold and exhaust system done now in addition to a remap, but I'm struggling to work out the costs involved when my understanding or what I need and how it fits together is a bit suspect!

If someone could illuminate this for me a little it would be much appreciated, ideally I want a system that's burbly and fairly loud without being "wake the neighbours" or "attract the police", and that I can get through an MOT and track noise tests without worrying.

I don't really want to spend more than £2.5k inc. remap for the exhaust and remap.

[Dan7954 35]

Nearly. In reverse, the Cat back connects to the second cat.. that connects to the overpipe then the manifold

[Church 209]

If you want to spend less, don't waste money on intake. Aftermarket drop-in airfilter will net most of possible intake gains for fraction of cost. Upgrading exhaust header (manifold) to good aftermaket catless one + tune will net most gains and depending on header choice may eliminate torque dip hence it's imho better choice.  It will also make exhaust louder, so i'd probably would stop at that. In general i highly advise reading opening post of this thread to familiarize with options/gains/prices. Should answer most of questions, at least once did for me.

[Paul 442]

Thanks Dan for the clarification!

I decided to drop the intake idea after the feedback on here, so it freed a bit of money up. 

Church that thread is extremely useful, thanks!

It looks like the best option is to go for a catless manifold for maximum performance gains, not pay too much for an overpipe (looks like it's kind of option if remaining NA, but since I want to go FI in the future I would probably replace it now), then get a catted front pipe (resonated to keep noise down from the headers???), with the midpipe and muffler supplied as part of the Injen kit. That sound about right?

(Will that still pass an MOT? Or better to go for manifold with a sports cat?)

[Church 209]

FI in future? That changes lot of things depending on choice if SC or Turbo.

1) I wouldn't bother with exhaust upgrades at all. All needed power more then enough can come from forced induction, as these cars are relatively light. Why spend then extra £1-2K on exhaust? In example of Cosworth, don't buy stage 1 NA upgrades, go stright for stage 2.0 SC kit. Even low power FI will be 1.5x-2x gains of max @NA and with mountain of torque early on.

About the only thing worth installing prior FI kit purchase is tune (eg. ecutek) & aftermarket filter. Those bits you can reuse with turbo later too.

2) if you insist on upgrading exhaust bits, in case if it will be turbo (hence with need to connect to exhaust path in header part) - don't buy headers. Turbo kit most probably will come with own, and very few aftermarket headers can be (at least partially) be used for turbo aswell. Supercharger is on intake only, it will see some extra gains with exhaust upgrading too and is "compatible" with all headers .. but see (1.).

3) Loudness (as heard by neighbours & cops :)) is affected by:

a.) cat deletion (and at lesser extent with replacement with HF cats)

b.) lack or removal of resonators

c.) bigger diameter piping. As 2.5" should be good to 250-300whp imho no need for 3" for this reason.

d.) and on contrary to first three bits turbo makes exhaust quieter.

If you had stayed NA and had bought/installed catless header, as you brought noise issues at all, then it probably matters enough for you, hence after catless header i would leave stock catback (will also save £), or at most get Q300 as quietest aftermarket one. Most of others + catless headers = LOUD. Saw cases of installing stock back, if installed catless header after installing louder aftermarket catback before that. But as you brought up FI .. (1.), so imho no need to buy catless header.

 

[Paul 442]

Ok, so in long term if planning to go FI (was leaning towards Fensport turbo) I should replace filter (and catback because I want to), get remap and leave the rest until later?

If yes then very happy as much less ££££ at this stage!

[Lauren 2259]

That's pretty much it. I reckon a secondary decat and exhaust system will give you a little bit as I have found with my car, though there are no huge power increases with being NA, but then again it will sound a lot better. 

Then you can remap if you want to of course. 

[Nicebiscuit 655]

Well this was an interesting read for me too... Cheers all.

[Paul 442]

Ok thanks everyone for the input.