20g vs t3/t4???

[bird man]

Hey guys. Im looking for some answers from some experienced DSM guys. i have a 99 GST with an evo 3 turbo upgrade. im currently at 250 HP to the wheels but am to that point where it was fun for a few months and now I am wanting more. my question is...What is the better choice on a front wheel car, 20g or t3/t4? I am planning on running on pump gas because this is still my daily driver. im using dsmlink to tune, I have 750cc's, 255 LPH. I do not plan on gettin drag redials and i know that with a turbo that spools up real fast im gonna burn the tires all day. I am leaning twards a 20G (60-1) i know its gonna be slow to spool but in the end it will really kick when it kicks in. I am wanting around 300 WHP. Am i heading in the right direction? if not please steer me in it.

 

[ericbev]

The E316G is more than capable unit to accomplish what you are looking for. Is your vehicle profile updated? It doesnt show a downpipe in your mod list. Do you even have all the proper supporting mods for you current turbo? Pretty heavily modified 2liter 16G setups have made over 400hp and seen mid elevens. Although this is on race gas with a very good tune and one hell of a motor, I am simply trying to illustrate that you should build around your turbo and find its maximum potential before going out and buying a bigger one. Cams and a SMIM would yeild some very nice results. Its also beneficial to have things like this in place before going to something larger so there are no bottlenecks in your system.

Seeing as you have DSM-Link and the proper fuel setup in place you are almost there already. Post a full mod list and give us a little more information about your tune etc. and whats going down with your car. We can move on from there.

 

[bird man]

Yes my profile is updated. unfortunatly no I dont have a downpipe. how much would that help? i do have the fuel system and DSMlink. my turbo just does not seem to pull as hard as it could. like i said....after tuning it on 91 octane at 16 psi it put down 250 HP at the wheels and 250 ft lbs of torque. It just does not seem like 250 when im on the street. i do want to keep it safe so i dont lean it out and pop the motor so i dont want to boost that much over the 16 psi mark. its tuned right now right about 11:1 thru 5k and then after 5k its a bit richer just so bw safe. there are minor timing advances up to 5k as well and after that everything is zero'd out

 

[keymaster]

Crank the boost up! 16 psi is nothing on that turbo. Over 22'ish psi you need to worry about head gasket/studs though. Get a full 3" turboback exhaust, the stocker is a HUGE restriction. I got mine custom made for $500.

 

[daren_p]

Yes my profile is updated. unfortunatly no I dont have a downpipe. how much would that help? i do have the fuel system and DSMlink. my turbo just does not seem to pull as hard as it could. like i said....after tuning it on 91 octane at 16 psi it put down 250 HP at the wheels and 250 ft lbs of torque. It just does not seem like 250 when im on the street. i do want to keep it safe so i dont lean it out and pop the motor so i dont want to boost that much over the 16 psi mark. its tuned right now right about 11:1 thru 5k and then after 5k its a bit richer just so bw safe. there are minor timing advances up to 5k as well and after that everything is zero'd out

Your main problem is your being to nice to that evoIII turbo, they don't even wake up till 17 psi. Get a down pipe on there for sure & make sure the rest of your exhaust is freed up as well (haven't read your profile yet). Turn your boost up to atleast 18 psi, this isn't going to hurt anything, if you have a fmic I would turn it up to 20 psi. If you like to be cautious add a set of arp headstuds. You have dsmlink so what kind of lb/min numbers are you seeing? Also think about adding cams, this seems to be the route to go before upgrading the turbo, this will be my next mod to get more out of the evoIII. With fwd you can easily see over 300 whp pump with the evoIII. To many people don't get the proper supporting mods, then say this turbo is too small & upgrade when its not needed, there is still a tonn more hp left in your evoIII If you just go and slap on a larger turbo and run it at 16 psi you won't be happy. The bigger the turbo, the more boost you have to run to get into its efficiency range, where they preform the best.

As for your tunning, looks like you got the timing backwards. You want to keep it zered out till 5500 (I start adding @ 6000) or so then start adding timing to get more out of the top end. Adding timing in the lower end will increase the chances to knock.

 

[ericbev]

Your main problem is your being to nice to that evoIII turbo, they don't even wake up till 17 psi. Get a down pipe on there for sure & make sure the rest of your exhaust is freed up as well (haven't read your profile yet). Turn your boost up to atleast 18 psi, this isn't going to hurt anything, if you have a fmic I would turn it up to 20 psi. If you like to be cautious add a set of arp headstuds. You have dsmlink so what kind of lb/min numbers are you seeing? Also think about adding cams, this seems to be the route to go before upgrading the turbo, this will be my next mod to get more out of the evoIII. With fwd you can easily see over 300 whp pump with the evoIII. To many people don't get the proper supporting mods, then say this turbo is too small & upgrade when its not needed, there is still a tonn more hp left in your evoIII If you just go and slap on a larger turbo and run it at 16 psi you won't be happy. The bigger the turbo, the more boost you have to run to get into its efficiency range, where they preform the best.

Very good advice.

Pickup a set of ARP headstuds for safety sake. The stock headbolts are known to "stretch" under 20+psi applications. This is bad. Many people run 21-22 psi on their pump gas maps.

Running the stock downpipe is definitley a restriction. Picking up a 3in piece should yield some nice gains in spool as well as a noticeablly harder pull on the top end.

Getting yourself the last restriction out of your exhaust setup, adding some boost, and tuning tuning tuning, will really wake up your current setup.

Also, was that 250hp claim on a dyno simulation, or a real one at a performace shop? Some sheets could help us see whats going on a little better.

 

[bird man]

it was at a performance shop that has a dynojet. thanks for the advice you guys.

 

[dalatinromeo]

Yeha I was going to say give my opinion, but everyone pretty much sum it up for you. Keep your EVO3. Get a DP, and crank up the boost on that turbo. I would say def 18-19psi,though you may heatsoak for smic. Wouldn't go pass 19 until you get a fmic, being that your smic will start to heatsoak. I wouldn't go higher until you get ARP studs. Keep us posted.

Stay boostin