BGW??

[LuPix_S15]

Ok folks,

It's time to start getting ideas together and think about tuning up my Silvia

To give you an idea, I would like to build a car that has a fair bit of track focus in mind so one of the issues I'm trying to sort out is the way I don't like it handling at high-speeds.

Even in a straight line at 100+ mph, the steering goes very light and the backend feels way to unstable for my liking. Maybe this is a personal thing but with a lot of track time lined up next year, I want the rear to feel planted... esp going round bends let alone on high-speed straight sections.


My question is, does fitting most forms of aftermarket GT spoilers really give a noticeable difference such as the one I'm interested made by INGS:

Yes, I hear the BGW comments coming up and I like my bare-arsed look that I've got now :nod: but I'm very function over form kinda person and if I think something will benefit the car, I'll do it and if it doesn't, I don't waste money and time on it.

An alternative might be just to get an RE-Amemiya diffuser custom fitted to the Silvia like other people have mentioned but is this also a noticeable benefit in getting downforce?


Cheers,

James :thumbs:

 

[JEZ 8553]

To be honest mate its very difficult to make a car both hardcore track and road use. For starters springs that are bearable on road will be too soft for the track, youll want plenty of camber and other extreme alignment settings which will make handling on the road scary or a chore at least. Then start lightening the car, removing rear seats and installing leightweight bucket seats + 6 point harnesses making it a pain to get in and out off. Lets not forget the all important roll cage...the list goes on.

Id personally avoid a BGW as to make it worthwhile and actually beneficial youll need start doing the above. A factory fitted option or a rear wing from a bodykit will suit the car for everyday looks and provide some high speed stability.

 

[DeanS15]

on the handling note jez, (not hi jacking as its sort of related), which alignment arms did you go for, bushed for road or track spec with pillowball type bushes? how do you find them?

 

[LuPix_S15]

Jez - think I know what you're saying mate Are you suggesting that mods like the GT spoiler won't be noticeable unless you are willing to push the car to it's extremities i.e. an all out track/racing prepped vehicle??


Take it a diffuser will also not be worth the money unless the cars are driven very hard?

 

[Dazz0i]

aero technology only comes into play when you're going all out balls in fast enough for them to create any noticeable downforce that'd improve things. if you're not goin' quick enough for them to create wanted downforce you'll be having a negative effect because they'll be causing un-wanted drag!

as with everything in the tuning world, everything you do to it, is a compromise of something in some, which way!

 

[JEZ 8553]

on the handling note jez, (not hi jacking as its sort of related), which alignment arms did you go for, bushed for road or track spec with pillowball type bushes? how do you find them?

I went for the bushed...pretty much for the same reasons. The rose jointed will be the danglies for track use but need inspection to check they arent wearing etc. TBH i wouldnt know the difference between with and without as Charlie fitted them for me before i even picked up the car . All i can say is the car drives lovely now ive had a full laser alighnment, camber, and castor done to Whitelines settings

 

[JEZ 8553]

Jez - think I know what you're saying mate Are you suggesting that mods like the GT spoiler won't be noticeable unless you are willing to push the car to it's extremities i.e. an all out track/racing prepped vehicle??


Take it a diffuser will also not be worth the money unless the cars are driven very hard?

Yeah, pretty much like Dazzoi said. My advice would be to do everything in moderation to a 'Fast Road' setup, that way you can enjoy the car on track and still have it usable everyday on the roads. 2 things definitely worth investing in is brakes and cooling. Also if you are planning on doing plenty of trackdays why not invest in a dedicated trackday car, something cheaper and FF which will allow you to get experience easier and cheaper ?

 

[R-Spec]

Jez - think I know what you're saying mate Are you suggesting that mods like the GT spoiler won't be noticeable unless you are willing to push the car to it's extremities i.e. an all out track/racing prepped vehicle??


Take it a diffuser will also not be worth the money unless the cars are driven very hard?

- Diffuser could be good if its fitted well, i.e. good flow from the floor - smooth transition

aero technology only comes into play when you're going all out balls in fast enough for them to create any noticeable downforce that'd improve things. if you're not goin' quick enough for them to create wanted downforce you'll be having a negative effect because they'll be causing un-wanted drag!

as with everything in the tuning world, everything you do to it, is a compromise of something in some, which way!

Over 50mph is the guide for aero to come into play

Yeah, pretty much like Dazzoi said. My advice would be to do everything in moderation to a 'Fast Road' setup, that way you can enjoy the car on track and still have it usable everyday on the roads. 2 things definitely worth investing in is brakes and cooling. Also if you are planning on doing plenty of trackdays why not invest in a dedicated trackday car, something cheaper and FF which will allow you to get experience easier and cheaper ?

FF!!!! :wack:


Fully agree with doing a sensible tune to keep it suitable for the road. when you make it right for track its horrid on the road

 

[LuPix_S15]

Thanks for the advice guys :thumbs:


I'll prob leave the spoiler idea but maybe still think about a diffuser. Good flow underneath the car has gotta be good (and that's at any speed)...


Yeah Jez - I'm lovin' the S15 too much to consider anything else for the track. Who knows, I'm definitely going to get myself another run around vehicle as I start to do more and more with the Silvia and drive it less and less on the roads. Wife's got the family executive tourer so in future, I won't be bothered about it being 'slightly' more uncomfortable lol :wack:

As you say, my ideal is something that's fun to drive and has improvement for the track but still be able to take the roads without too much hassle. Don't worry, brakes and cooling are top of the list.

To give you an idea of what I want to do, it's not in-yer-face big bhp that many like the idea of. What I want is something that's more nimble but not stripped with rollcage or anything extreme. Things like a lighter flywheel, v-mount (may have to go custom here), big brake conversion kit are all on the list.

 

[Dazz0i]

also, BGW's aren't as efficent as you'd first think. because they're attached to the boot lid, there's flex in the boot lid, they're not as solid as you'd think.

that flex, is possible force lost before it's even done anything useful. ideally, they want to be attched to the ends of the chassis legs, again though, it's the thing about compromise. can't imagine you'd want to be permanantly fixing a BGW to your car! LOL

a bloke i know, used to work for elmore mclaren building F1 engines before starting his own engine build company, the bloke knows more than i could ever dream of understanding, he explained about it all and aero pro's and con's....

heres one..... know the "sonic hedgehog" spikes on the MR/FQ evo's roof.... they're to cause more turblance in the air flowing over the car, to make it stick to the car and create more downforce. it causes more downforce due to the pressures of the air flowing over and under the spoiler being at different pressures! This conversation did go on for a while.... and .... i've forgotten alot of it! HAHA hours i can listen to him! LOL

 

[LuPix_S15]

lol - always wondered what them 'shark fins' on the later Evo's

 

[Dazz0i]

now you know! LOL

 

[Pazz]

Hey InitialD,

Do you have locking collars fitted? That would give a tighter feel to the back end. Also have you had full alignment done?

F1 car aerodynamics are crucial, as shown by all the advancements, but as R-Spec said, aero dynamics only come into effect above-50mph. F1 cars are nearly constantly above that threshold so play a major part in maintaining grip.