Custom part

 

Anything above 10.5:1 is considered custom and not off the shelf. I had mine done by Wiesco and honestly for custom pistons I paid like 500 bucks for them. Problem I do have is tuners are afraid of tuning the higher compression stuff with forced induction. Specially with a larger turbo like I have.

 

Yep your absolutely correct.

 

that's what everyone was talking about, so when you bring it up, it's easy to assume you were still being on topic.

Don't they prefer larger turbos? More CFM with less heat should be a good thing.

 

My setup was 9.0CR Mahle piston with a 2.3+Mivec engine.
GSC S2 Cams.
Static compression test was around 152psi average.
I went for a thicker Tomei Headgasket, the 1.8mm thickness option.
Average compression dropped to 145psi.

I've done this to run only pump gas and ~30psi of boost.
Best pump gas we have here is 93RON (98MON).

 

Idk the tuners I have been talking to do not seem to like larger turbos just small frame **** or something. kevin Jewer said he would tune the car but we haven't been able to get a day or time straight, Whalen said he would tune it but I have to get it running, a few other less known local tuners will not touch it being they are afraid to tune with such high compression. My best bet is Jewer and or Whalen. Problem is Idk what is wrong with the car. It is acting up now I put new fuel pumps and ignition on it. Now all of a sudden map sensors all off and I think that is the reason it will not start. Odd my map sensor reads 14 lbs of boost with key on. I ordered another map sensor and it does the same so IDFK what is wrong anymore and its pissing me off.

 

I've never used a Haltech, but if I was you I would start by double checking the sensor scaling in the ecu matches the specs for the map sensor and the input is correct for the input the map is on. If that's good put a DMM (Digital Multimeter) on the signal wire from the map sensor and verify its outputting the correct voltage for atmospheric air pressure.

 

12.5:1 on a street car 4g63 will be harder on things. I hope it works out for you .

 

Mike, those are your compression test results, leakage wise. These results have nothing to do with your static compression ratio. Your CR , is a ratio of fuel and air, and it can only be determined through precise measurements and calculations, of all the spaces and parts used in your engine. There are online calculators if you do not wish to do the formulas yourself.

The thicker head gasket will affect the compression test and the static CR, it adds space.

Here is a good CR calculator : http://www.csgnetwork.com/compcalc.html

Also a leak test is much more indicative on an engine's health than a compression test.


Also 93 RON is not 98 MON, 93 RON is 84 MON or 88 AKI. 98 MON is 107 RON or 103 AKI.







Marios

 

In regards to how much static CR you should run, on a road car, even on e85, 10.5:1 should be your max. I would run 10:1 on e85 and no more.

On 93 pump, the stock CR is perfectly fine.


Now if your car is a dedicated dragster car, that runs on methanol, nitromethane, etc, you can run 12:1 even 13:1. But on a road car, there is absolutely no point, you will not actually gain anything by doing it, and it might as well become a restrictive factor on the tuning aspect.


Personally I run 9.7:1 on my setup, but its on 100+ oct RON, and the fuel can take it, with timing and boost being spot on.







Marios

 

I have beat the **** out of it since 2014 and not had any issues what so ever. I have run 30 and over 40 lbs of boost no issues other then broken tb plate. The car is a tank when it isn't a paper weight.

Oddly enough even with all the correct #'s in for the scaling and what nots it still acts up. After playing with the car a little last nite I think there is a ground issue somewhere. I added my relay box for my fuel system, a new radio, and this ignition so maybe I missed something. Its hard sometimes when your working 12 hr days plus almost an hr drive time one way and by the time you get home your just spent. I will try to look at that again tonite to verify. Sorry for kinda hijacking the thread.

 

I am glad your setup works for you and in theory works great. Have you ever spooled a larger turbo on high compression? Trust me it works well even on a street car limited to only 8000 rpms.

 

My setup works really well, in applied action, with excellent results. I used VD to verify those. I already run a large turbo. This is high compression, as it is higher than stock. I mapped my setup to 10K rpm, and I've run it constantly to 9.5K on the street.

High CR has nothing to do with your rev limit. Turbo hondas and bikes, on high CR, rev to 10/11K and 15/16K rpm. Your CR has all to do with the fuel you are going to be using. If that fuel can take it, provides no restrictions and you are able to tune your vehicle the proper way, then that specific CR number will work for a street setup also. As I said on pump e85, personally I would not go higher than 10:1.


Nevertheless, all the best with your build.








Marios

 

run diesel and you can have all the compressions

 

I think you missed where I run a 2.4 engine. I am limited to about 8500 or in my case 8000 rpms. I know the revs have nothing to do with compression and yadda yadda I think you misunderstood where I was coming from here.