installed HIGH compression pistons OMG

[armandovivoni]

so I installed some high compression pistons on my 4g63 and what a difference, it has become fun to drive again. no turbo lag. today I took it to the shop that makes the programing for my stand alone computer. I set it at 5 psi. just to be safe until I can go to the DYNO. I have a T4/T3 turbo .70/.48 stage 3

I raced a guy from the same shop. he has a T4 turbo .60/.58 ,same stand alone computer I have, same manifold, only big difference is I have hks 272/272 and he doesn't. he has the 4g63 engine on a much lighter mitsubishi mirage. he is set up to 14psi.

he got beaten jaja, I pulled 2 car lenght by 2nd gear, 3rd gear I was still 2 cars ahead and he decided to stop. I cant wait to tune my car at 18psi

 

[jott5555]

hmm.. well its got to be fun controlling that beast @ 5psi, what compression raito did you go with?

 

[armandovivoni]

I really cant say exactly what compression they are cause I dont really know. but I can tell you that I compared them side by side with the non turbo 9:0.1 and they have a much higher dome. the owner of the dsm shop I take my car to said they are like 10 maybe 11:1. I got 225 when I did the compression test. these are not forged pistons, they are actually mitsubishi thats why Im running only 5psi. I dont know the limits of these pistons. but I'll keep posting when I take it to the dyno

 

[anconover]

If you are serious, and put a piston in that you dont know the compression of, and nor does ur 'dsm shop' then not only are you a total moron, so is your 'dsm shop'. I bet youll make loads of power at 5psi.

Were they stage 5 pistons? I hear stage 5 is the fastest.

 

[Littlebeeper]

wish you luck trying to get to 14 PSI with an 11:1 compression. not that it can't be done but as a daily driver? I wouldn't even try.

 

[DevilSperm]

ill bet in a week you are back here asking why your head lifted off the block when you were racing

 

[armandovivoni]

You know what? I also thought like you, I said to my self this wont work. but changed my mind when it was finished. 5 psi beating a much lighter car with the same engine running at 14psi made me change my mind. without going to the dyno. I think its great.

ohh and dont be a hater. be happy

 

[Turbo Talon DL]

I see you have a standalone EMS, BUT.....do you have a good way to monitor EGTs and all those nice things that engines dont like? You said 225psi, thats closer to 10-10.5(ish):1 comp ratio. Either way, I would take those pistons out before u MELT THEM

 

[spoolin27awd]

OK man try to help you understand why you have a time bomb on your hands if this is really the compression you have

does any one know what Effective Compression or static compression is ?
well all of you that work on these cars should especially if you have a turbo car or other forced ind. car anyway here we go


with the 11.1:1 compression say that you are running 5 psi the static comp well be 14.7:1
now that alone is race gas comp. my low 8 sec camaro runs 14.1:1 and it is a n/a car,but big one g rods will take it for a bit now say that you are running 18psi on that same comp.now it comes out to be 24.4:1 under boost!!! i don't know if you know this but small diesel engines run 22.1:1 comp think about it. you need some strong rods and some good tuning now just to blow your mind here ya go: 11.1:1 comp at 20psi comes to 25.9:1 and at 25psi it comes to..............29.7:1 now with 10.1:1 it won't change much,you are much safer running low comp and higher boost levels on the street as long as you have supporting mods and a turbo capable of pushing high cfm so the air charge stays a little cooler

 

[spoolin27awd]

ps: i will get across that finish line before you because your bottom end well be puking out the pan!!!!!

tata for now
ME

 

[armandovivoni]

I have a pyrometer for EGT, and a whole lot of fuel. MSD inj. 1,152cc, full 8an fuel line, aeromotive 1:1 FPR, aeromotive 10an fuel filter, venom 400lph pump, 8 gall. fuel cell, Zengineering 8an fuel rail.

I was looking into water inj. I hear what you say about melting. I just want to try things out. Im stiking with them for now. and see what I can get from them. until I complete buying the new setup. forged pistons (low), rods, and ballbearing turbo

 

[hose101772]

Before you guys dismiss higher compression setups,you should know there are a few guys purposely running 10/1 w/ high boost.Reports say they do just fine on pump gas.

 

[armandovivoni]

spooling, nice info man. and what would 8:5;1 comp. pistons with 30psi of boost give?

 

[spoolin27awd]

Allot it would come out to 25.8:1 but there are ways to make more power safer.......like what you say/ make your engine more efficient!! like i said strrrroonnnggg rods and good gas

 

[armandovivoni]

so then 10:1 compression pistons with 20psi is still less static comp. than 8:5;1 with 30psi. well before this setup that by the way is on a 6 bolt 4g63. I used to have on my 7 bolt eagle rods with stock 8:5;1 with a t4/t3 .60/.63 stage 3 turbo at 30psi and had no problems with the block. once I went 30psi plus a 75shot nitrous on racegas C116 with 780cc inj. with no problem. what happend? CRANKWALK.

I dont think the head will come off. I think my cometics hp headgasket with my arp head bolts torqued at 110LB will prevent that.

Now I have a 6 bolt. I could not use my eagle rods cause they wont fit. but I heard of stock 1g rods to hold 400+ hp, and to be honest I dont think ill get that HP on these pistons.

 

[Turbo Talon DL]

OK man try to help you understand why you have a time bomb on your hands if this is really the compression you have

does any one know what Effective Compression or static compression is ?
well all of you that work on these cars should especially if you have a turbo car or other forced ind. car anyway here we go


with the 11.1:1 compression say that you are running 5 psi the static comp well be 14.7:1
now that alone is race gas comp. my low 8 sec camaro runs 14.1:1 and it is a n/a car,but big one g rods will take it for a bit

To me, its not so much the rods i would be concerned about, i'd be more worried about bearings and such. One little knock and ping, something could be hurt. But, he sounds like he has a good setup with fuel, timing, and what not. You could quite possibly be safe on your setup. I assume you run some ultra mega f*ckin high octane fuel? Anyhow, keep us posted, this kind of stuff is always interesting.

 

[Defiant]

so I installed some high compression pistons on my 4g63

That's good. You'll know just how to go about replacing them. Real soon.

But, it will be a fun week.

 

[armandovivoni]

well defiant. about that pic. that can happen to any comp piston. as you can see on the pic those are low comp. pistons.

turbo talon dl. well about the fuel. I guess on the DYNO i will know what psi to run for daily driving on pump gas. 93 octane were I live. and what psi to run on race gas 116 octane.

 

[Thomas91169]

usually the given rule is high compression and boost do NOT get along. its so much harder to tune and so easy to get just a wee bit of knock and bang, its all over.

theres reasons why you dont see turbo hondas running over 10psi on stock engines, and when they do want more boost, they get LOW compression pistons. theres a reason for that. low compression is better for boost(unless youre a diesel). high compression is good for all motor and/or nitrous setups.

congradulations, youve sucessfully taken a step back. get ready, cause like defiant said, its not gonna last long under any circumstances.

 

[armandovivoni]

please dont compare a honda engine (aluminum) with an iron block 4g63. with much more harder internals.

there is also a reason why 4g63 can handle 400hp on stock internals and hondas CAN NOT.

 

[spoolin27awd]

only time will tell (i know what will happen like defiant pic says)????and i have ben doing this for a long time

 

[notractiongst]

please dont compare a honda engine (aluminum) with an iron block 4g63. with much more harder internals.

there is also a reason why 4g63 can handle 400hp on stock internals and hondas CAN NOT.

Says who? My freinds b18 has seen numerous 400 WHP passes and it is still running strong...Its a stock internaled GSR motor
112 octane does wonders

 

[armandovivoni]

I seriously doubt that your friends b18 has stock internals.

if he has stock internals(high comp pistons) and has 400hp that means that what I did with high compression pistons will work just fine. hmmm tell your friend to tell you the truth

 

[Thomas91169]

please dont compare a honda engine (aluminum) with an iron block 4g63. with much more harder internals.

dont compare them? you just made yourself one. a high compression 4g63 you just basically turned yourself into a 2.0 honda.

do you really think people do low compression when doing big boost just for shits and giggles? high compression+boost= . look at shep and rau, theyre running low compression for a reason. if high compression with boost was the way to go, shit half this board would jump on the bandwagon.

and another thing, you better have god tuning that thing.

:WTF: = as they tune your car
=you driving after tuning
=after it blows up
me(and the rest of the board) after your next thread is "DSM's are pieces of shit, why does my car blow up at only 6psi? im getting a honda"

 

[armandovivoni]

! thats funny man. I have some dsm friends here were I live and they said the same thing. (I made a honda) or a eclipse type R jajaja. but man dont be so negative, you are already blowing my engine up at 6psi!! I need to know the results!! Im going on tuesday to the shop to get it street tuned at least to 15psi . I would like to post videos of these I just dont know how