General 4g64 and dsmchips stage 3 chip

[duwackerTSi69]

Hey gys, when I ordered my stage 3 chip Jeff asked me what piston ill be using with my 6 bolt build and I told him the 7.8:1 1g pistons? However, i decided against the 6 bolt swap and now am doing the 4g64 hybrid. Ill be using the stock 4g64 piston and limiting my boost to 10 psi with 14b. On my stage 3 chip its set for 43psi base fuel pressure and was wondering if I should send Jeff the chip back and change a few things? I am using the stock pistons just so I can get my car moving because I am in need for it.

And can someone break it down for me on why what pistons is important for the chip setup that I have? I am a newb to this sorta thing with tuning??

Thanks guys

 

[JayRolla]

If I had to guess he wad going to set up your timing map based on the compession u where going to run. I would call him up and ask him the question since he built the tune for yea.

 

[the_mork]

Was this the question you wanted to ask me at one point? I never stick around on facebook so I always see the messenger service a few hours later.

First of all, you can probably drive the car with the chip provided but don't expect it to be a great tune. It will probably be fine for most things and should still haul ass but depending on the changes you make the timing curve may be too aggressive.

Basically the reason that pistons make a difference is the compression ratio. A higher compression ratio will (in general) give you more power but will be more prone to knock so often you have to run less timing or lower boost. As for a 43psi base pressure that shouldn't be any problem unless you have an AFPR and enough pump to run higher pressure in order to increase injector flow. There will also be a number of differences in the tune because of the larger displacement of your engine. I don't have enough experience with tuning to tell you what those differences will be exactly but I expect that Jeff has enough tricks up his sleeve to make it worthwhile to send the chip back to him.

FWIW that 14b is also going to run out of breath very quickly on that engine so you'll want to get your new pistons and a new turbo fairly quickly so that you can enjoy the work you're putting into this.

 

[duwackerTSi69]

Was this the question you wanted to ask me at one point? I never stick around on facebook so I always see the messenger service a few hours later.

First of all, you can probably drive the car with the chip provided but don't expect it to be a great tune. It will probably be fine for most things and should still haul ass but depending on the changes you make the timing curve may be too aggressive.

Basically the reason that pistons make a difference is the compression ratio. A higher compression ratio will (in general) give you more power but will be more prone to knock so often you have to run less timing or lower boost. As for a 43psi base pressure that shouldn't be any problem unless you have an AFPR and enough pump to run higher pressure in order to increase injector flow. There will also be a number of differences in the tune because of the larger displacement of your engine. I don't have enough experience with tuning to tell you what those differences will be exactly but I expect that Jeff has enough tricks up his sleeve to make it worthwhile to send the chip back to him.

FWIW that 14b is also going to run out of breath very quickly on that engine so you'll want to get your new pistons and a new turbo fairly quickly so that you can enjoy the work you're putting into this.

Well I have a 255hp in the tank, and per Jeff's recomendations I did the syphon tube mod to try and decrease the possibility of over run issues with evo 560's. The 14b is more or less to break in the engine and new TRE trans properly. I figuired that the 14b on a 2.4 is like having a T25 on a 2.0?

Im still looking into new piston choices so that I dont have to use forged ones. John over at Dsmgraveyards told me about a cast piston that is lower compression and is for the 4g64. But he was alittle busy so he had to cut the phone call short.

What pistons are you running in your spider, mork? Just curiouse as to the way you went with your engine setup..

 

[the_mork]

I have a stock longblock and so far I'm perfectly happy with it. I'm running 23.5psi on an evo3 16g.

I would definitely suggest a Holset once the car is broken in and you have the money to implement it. You're also going to need a lot more injector to get that motor to reach its potential after you have it built.

 

[duwackerTSi69]

I have a stock longblock and so far I'm perfectly happy with it. I'm running 23.5psi on an evo3 16g.

^ So you are running 23.5 psi on stock 4g64 pistons? I am assuming you can do that with your evo ecu and great tunning to reduce knock? Just trying to understand from what you told me befor..

I would definitely suggest a Holset once the car is broken in and you have the money to implement it. You're also going to need a lot more injector to get that motor to reach its potential after you have it built.

I actualy have a HE351 which is basicaly a revised version of hy35, and the little sister to the hx35. I have a pretty good mock up of a 3 1/2 DP that will be able to clamp on to th stock v-band o2 housing. I am still un-decided as to what manifold I want to use? The holset is what I realy wanna use when I can get someone to help with tuning?? I figuired I would drive around with the 560's and 14b for the first part of summer and then get some fic's and an AFPR. Do some tuning logs with evo scan, and make adjustment from ther. But thats wher Ill need the tuning help. That stuff is verry hard for me to understand.

 

[the_mork]

I think you've misunderstood something along the line with my car. My car came stock with a 4g63t in it. It is exactly the same as the hard top gs-t from the firewall forward. Only the NT spyders came with a 4g64.

What are you planning on tuning with once you switch setups? You can probably send your chip back to Jeff once you know what your final setup will be and have it all put up together but otherwise there are more than enough people around our area with experience tuning everything out there. I only have experience with flashable ecus but if you go with dsmlink I'm sure there are some people that can help and I can answer general questions for it.

 

[duwackerTSi69]

the_mork;152093503]I think you've misunderstood something along the line with my car. My car came stock with a 4g63t in it. It is exactly the same as the hard top gs-t from the firewall forward. Only the NT spyders came with a 4g64.

My fault, I forgot that some of the spyders came 63' powered, and not to mention Tony said you turbo'd your car... I dont know why he said that??

 

[the_mork]

I'm not sure either unless he mistook me telling him that I had put a 16g on it for meaning that it didn't have a turbo to start with.

Who knows, usually when I see Tony I'm already half in the bag so I could easily have miscommunicated.

 

[jeffo]

As Mork said, you can't run as much timing advance or boost on a high compression engine, so I have quite a few different timing maps that I modify as needed. You really need to finalize what the compression is going to be.

 

[Afroclipse]

Jeff charges $25 bucks for a swap.

 

[duwackerTSi69]

Im aware of his fee for reburning a chip or to change things. I try to do more reading then asking questions, but sometimes you cant get what you want when you need it.

Hows it going Jeff? I still got that chip and eprom all tucked away in my bedroom waiting till one day I can put it to use? Oneday,.. I am trying to get all thes options figuired out here on Tuners so that I dont blow up your email. I know your a busy guy, but hey, i got to give it to ya. You are one of the best guys I have ever dealt with as far as replying back about questions and just plain helping someone out with what you can over the net... A++ to you

I will make some calls to slowboy and dsmgraveyards tomorrow and see if I cant get some low compression pistons squared away??

 

[the_mork]

You don't necessarily need low compression pistons. Just make sure that if you go with somewhat higher compression pistons that the rods, head gasket, and hardware can deal with the increased cylinder pressure. I remember at one point a guy making a pretty decent thread about a budget high compression stroker, you may want to look into that.

Have you spent some time just reading in the stroker section? I'm sure you can just look at people's setups and then emulate one that you like.

 

[m_0ney_pit]

Yea definitely get a new chip burned, it'll knock like crazy if you try to run the 4g63t ecu on the 9.5.1 compression block. You'll want to take out a bunch timing out in the load range right before boost and in the 0-7 psi range and add timing around 7-10 psi. You also need to richen up most of the mid-load rpm points from vacuum to 7ish psi. At full throttle this is pretty much the 2500-4000rpm band. Also lean out the top end from 4500-5500 rpm because it will be way rich. Idle timing also needs to be set to 7 degrees from 5.

Also it would be a good idea to run the 4g63t fuel pressure and the regulator unless you changed the head. The SOHC head uses a different base pressure 1 because it is NA and 2 because the injectors are placed differently on the IM. The 4g63t IM has the injectors very close to the intake port. The SOHC head has them much further away...I'm guessing this is why the base pressure is higher.

As a last word, you really want dynamic tuning for the 4g64 stock piston setup, reason is you want to get rid of ALL the knock. I would share my fuel and timing maps with you but I'm not at home right now and won't be until april. I plan on making my modified 4g63t maps available for people that are running a 4g64 turbo setup in a spyder with the stock pistons around this time. Now just need to find a way to host the files.

edit: you can use an AFC to leanout across the board forcing the ecu to higher load columns to get less timing and richen up where you need it but this is not a good idea. You can see the crappy results in my dyno if you look at how unstable the AFR is.Never knocked more than 6 counts though haha

 

[the_mork]

What type of files? If you are talking about a rom then you can just attach it to a post here.

 

[m_0ney_pit]

yep the rom

What type of files? If you are talking about a rom then you can just attach it to a post here.

 

[williillii]

Any one have any more info or want to post up a timing map for a 4g64?

Im working on mine right now and am curious as to what others have done...I ran a 95 eprom ecu for a bit...it was ok as far as timing. Had to richen up the spool areas...

Now Im running a stock evo rom with timing peaking at 18 degrees with only 1-2 occasional counts of knock right at the beginning of the pull.