Supporting mods for use with 15G's

[Streetwarriorz]

My GTO project is coming to a fast pace now as we head into the UK show season so will see alot of me on here asking alot of questions!!

I take in knowledge fast so will try to answer some too!!

Right to the question:

What supporting mods are best for use with a pair of 15G's?? injectors, piggybacks etc

I have read that other turbo's in certain circumstances are a better mod but quite simply I have access to a pair of new chargers for only a couple of hundred UK pounds (about $400) hence this choice of route!

Pretty much I need it to be realistic in cost though, I'm not doing it on the cheap, but I'm not a multi platnum rapper either

Cheers everyone

[Hotshot8792]

well, it all depends what your setting up for. If you plan on running pump gas levels on 15G's, I would go with a Walbro 255 lph fuel pump (or something equivalent), 550cc injectors, and an S-AFC. If you are planning to dump race gas in some and turn up the boost at the track, then i would go with a Walbro 341 lph, a Supra pump, or something equivalent, 660cc injectors, and a greddy e-manage.

At this point, I would also look to upgrade intercoolers. The cheapest route, yet effecient, is buy a couple of 1st gen DSM sidemount intercoolers (you can find them easily at www.dsmtrader.com) and you can get two of them for around 100 bucks shipped. Then you can find someone on 3SI, or someone locally who is good with welding, to mod the intercooler piping and brackets so that it will fit your car. If you find someone on 3SI who does the service, the total cost will probably be $400-$500 total including the purchase price of the intercooler, and they are one of the biggest sidemount upgrades available for our cars.
You can also look into an FMIC. If you want to take the most effecient, yet least expensive route for an FMIC, look into buying the 14 inch core for the 3/S from custom coach (i believe their site is www.speedpartsrus.com) and request a single in and single out for a 3/S, then go over to PPE engineering (www.ppeengineering.com) and buy their piping kit. Custom coach used to do the piping kit, but i dont think they do anymore, however, you can still check with them first and see if they still do the piping kit. If they do and you decide to do that, you willl probably end up with a dual in and single out FMIC.

Thats probably all the basics you need to get 15G's going. You can still use the stock intercoolers if you want, as they've proben to support 15G's, but i would still look into upgrading.

[Streetwarriorz]

Hi and thanks.

The intercooler issue isn't a problem I have a FMIC on available to me pretty cheap, 3" inlet and 3" outlet, I think it has a 24x6x3" core.
As for the pipes the welding gear will sort that one

I already have the fuel pump in and the hotwire kit done, so really just the 550's and an SAFC needed then??

I have the rebuild lined up in the next month so will need to get it all done at once

I will be running on pump gas but also using a high octane additive as usual

So realistically what sort of output wheel or engine can I expect to see?

[Igovert500]

~400AWHP give or take

Really depends on what you mean by octane booster...

[xXxRocker5150]

^yeap, according to stealthee's research, the NOS brand octane booster is the only one that significantly works....

[Streetwarriorz]

Right so,

15G's plus 550's or 660's, an SAFC2 and preferably a FMIC are all I'll need for the upgrade

Excellent !! Giving around the figure of 400AWHP so about 480 or so at the engine.


So what level of nitrous hit (wet obviously) can the GTO take without concern?

[Hotshot8792]

octane booster isn't going to do anything for you. When it raises it a point, it means 0.1 Octane. If you want higher octane, stick with the race gas such as C10 (110 octane) and C16 (116 Octane) etc. If you do plan on using it, and you want to turn the boost up, i think 550cc's aren't going to be enough, i would go to 660cc's. Once again, with 660cc's, I would use a greddy e-manage instead of an s-afc. Reason being that in most cases of our cars, when trying to use just an s-afc with anything over 550cc injectors, your ignition timing tends to get a bit too high. Your timing will increase when you tell the ECU there is less air coming in that there actually is. The e-manage allows you to adjust timing levels where needed. I hope this helps.