What can i expect ???

[Pete H]

1st off hi i am new to the site and looking to but a nice S15,i have a few questions,i would prefer to buy a modified one running more power arround 400 bhp so please any advice,
Q.1-What power will the standard turbo make/handle ?
Q.2-What is the max the standard engine internals handle?
Q.3-Do they all have 6 speed box?,and what power are they ok to?
Q.4-is a front mount needed?
Q.5-Is the standard ecu re-mappable,or is a upgrade needed?if so which 1
Q.6-How many different models are there?and which is best,

Any other help welcome guys,like i say looking for a good 400bhp one,but need to know how much this will cost.

Thanks pete.

 

[japmadlad]

1st off hi i am new to the site and looking to but a nice S15,i have a few questions,i would prefer to buy a modified one running more power arround 400 bhp so please any advice,
Q.1-What power will the standard turbo make/handle ?
Q.2-What is the max the standard engine internals handle?
Q.3-Do they all have 6 speed box?,and what power are they ok to?
Q.4-is a front mount needed?
Q.5-Is the standard ecu re-mappable,or is a upgrade needed?if so which 1
Q.6-How many different models are there?and which is best,

Any other help welcome guys,like i say looking for a good 400bhp one,but need to know how much this will cost.

Thanks pete.

1) A Standard turbo S15 makes 250bhp in japan on jap fuel, 102RON so over here on 97-99 you would probably say 230bhp. The GT28R is rated around the 300-350 mark.

2) standard internals will handle around 1.4 bar of boost

3)Spec R all have 6Spd manual. You can fit a 5spd but I wouldn't bother. I know of S15's handling 400+ bhp on the 6 spd. Some have a circlip issue which is well covered on here if you use the search.

4)FMIC would be needed for high power. standard wing mount wouldn't be up to it really

5)Standard ECU is not mappable:no:. Best ECU is debatable. I use an Apexi Power FC D-Jetro. For value, functionality & ease of use it can't be beaten in my book. Depends what you want really. you can spend around £700 on the PFC ( L-Jetro is cheaper £450 I think ) or go all out & spend a couple of grand on a Motech or AEM ECU with traction control :ghey:, 2 stage launch control & anti lag. Up 2 you really.

6) All models can be found with the search function. Basically Spec S = Non turbo 165bhp, Spec R = Turbo 250BHP, there is a convertible :ghey: varietta model with a 200BHP SR20DE IIRC, & an Autech model aswell.

 

[Matt_S]

Buy mine! Not far off 400bhp. Needs a set of cams and a remap and youre looking at high 3's

 

[Matt_S]

2) standard internals will handle around 1.4 bar of boost

WRONG!

So why have I seen some SRs used hard for a couple of seasons (and as used dailys) make nearly 400bhp on higher boost with bigger turbos? :wack:

1.4 bar on the std turbo your just blowing hot air into the engine pretty much. Dont run more than 1.2 and your well within the std turbos efficiency.

Saying a generic statement like you did is bad advice imho.

 

[japmadlad]

I have a bigger turbo on my S15 but I was always told that the standard internals could only handle around 1.4 bar pressure, but even at that you would probably be best with forged & a metal head gasket

 

[Matt_S]

Ah, so you mean std compression!

Boost not really relevant. Bigger turbo will give more volume of air and make the engine work harder. Therefore the bigger the turbo, the lower the max 'safe' boost pressure, as a rule of thumb.

If that makes sense.

 

[japmadlad]

I'd say it will in the morning matt

 

[Matt_S]

Hic!

 

[japmadlad]

 

[JEZ 8553]

The standard ECU is mappable as done by Jez @ Horsham-Developments and makes it a far cheaper option than getting a piggyback/replacement ECU.

 

[Matt_S]

The standard ECU is mappable as done by Jez @ Horsham-Developments and makes it a far cheaper option than getting a piggyback/replacement ECU.

Yes and no. Each to their own, but I prefer the fact that it HAS to be mapped to YOUR car with the aftermarket ECUs. Each car/engine si different and so whats good for the 'master' car might not be the same for yours. Different exhausts/manifolds/filters/FMIC etc
Apart fromt eh obvious one that they tend to be 'staged' whereas if you want to do lots of stuff together, you just map it the once with an ECU.

 

[Yakozan]

Q.1-What power will the standard turbo make/handle ?
I would say about 320-330hp. Maybe more with aftermarket cams.

Q.2-What is the max the standard engine internals handle?
stock bottom end will handle 400-450hp if it's in good condition. However you're pretty close to the edge and I would feel safer with uprated just as a precaution. But we have several S14s here in Sweden running 400-450hp on standard internals. Just some small work done to the head I beliave.

Q.3-Do they all have 6 speed box?,and what power are they ok to?
Most Spec-R are 6-speed, but it was also available with an auto box but that is pretty rare. Spec-S are 5-speed or auto and there also was a Autech version with N/A engine and 6 speed box.

Q.4-is a front mount needed?
Doesn't have to be a front-mount, but an uprated IC is needed if you want more power.

Q.5-Is the standard ecu re-mappable,or is a upgrade needed?if so which 1
It is remappable, but there is a very limited crowd offering this service in Europe. Most people get aftermarket ECUs. The Apexi Power FC is a good value for money ECU, but there are also lots of piggybacks available like and also very expensive ECUs like Motec.

Q.6-How many different models are there?and which is best,
basically there are 4 models, The turbo Spec-R (250hp), the N/A spec-S (167hp?), the Autech (200hp N/A) and the Varietta (cab spec-S).
Spec-R is the best followed by the Autech. There was also an aero-package available as a factory option kit which included rear wing and side-skirts. As an additional option there was an aero front bar and rear spats.
If I was buying a S15 today I would try to find a full aero Spec-R. But they are pretty hard to find these days. There are lots and lots of other options like HID, leather front seats etc.

 

[JEZ 8553]

Yes and no. Each to their own, but I prefer the fact that it HAS to be mapped to YOUR car with the aftermarket ECUs. Each car/engine si different and so whats good for the 'master' car might not be the same for yours. Different exhausts/manifolds/filters/FMIC etc
Apart fromt eh obvious one that they tend to be 'staged' whereas if you want to do lots of stuff together, you just map it the once with an ECU.

I think Jez can only do custom maps for the S15 anyway ? Thats what im having done, much prefer it that way as you say. Its only £350 which is a good price imo.