I am wondering if I can put 9.6:1 compression n/t 2g pistons in my 1g and get a high pressure MLS metal head gasket and be able to run 300hp with the 14b turbo in putting in. Probably only run about 250hp daily and 300 at the track but I still want it to be safe more then anything. I want to stay at high compression if I can because It will reduce my boost PSI that I need by about half...Think about the spool time here. Should but my 1/4 mile time considerably with less spool time. Also, the highest octane gas they sell out here is 91 =/
1991 Mitsubishi Eclipse GSX - SOLD 2006 Mustang GT Convertible
#10716, "RE: 9.6:1 comp, head gasket handle 300hp?" In response to Reply # 0 May-28-04 02:10 AM by HybriDSM
9.6:1 will be a disaster to tune. Honestly. People have run 11's and ALOT of people run 12's on the 14b with stock compression.
I cannot imagine what a nightmare tuning 9.6:1 would be. Any tiny bit out of tune and you'd be getting knock counts of 50.
Rule of thumb is that turbo cars love low compression, and you generally want the turbo to do all the work. I almost made the mistake of getting 9.0:1 compression pistons for my rebuild, but went with 8.3 instead.
#10718, "RE: 9.6:1 comp, head gasket handle 300hp?" In response to Reply # 1
Edit: I also for got to mention that 420A pistons have a different bore than the 4G63. You'd have to pull the engine to get it overbored and chances are, that over bore wuold make your cylinder walls far too thin. A .060" over 4G63 pistons is still only 86.5 mm. That and NT pistons aren't designed to hold boost. There are a ton of reasons why you won't want to do this.
#10719, "RE: 9.6:1 comp, head gasket handle 300hp?" In response to Reply # 3
Originally posted by HybriDSM Edit: I also for got to mention that 420A pistons have a different bore than the 4G63. You'd have to pull the engine to get it overbored and chances are, that over bore wuold make your cylinder walls far too thin. A .060" over 4G63 pistons is still only 86.5 mm. That and NT pistons aren't designed to hold boost. There are a ton of reasons why you won't want to do this. 4G63 = 85 mm or 3.346" 420A = 87.5 mm or 3.445"
How much boost would I need to make 300hp with 9.0:1 forged?
1991 Mitsubishi Eclipse GSX - SOLD 2006 Mustang GT Convertible
#10720, "RE: 9.6:1 comp, head gasket handle 300hp?" In response to Reply # 4
420a pistons just won't work in the 4g63. End of discussion.
If you are going through the mess of turboing a non-turbo 4g63, just pick up a turbo engine. You will spend a lot less money for a whole lot more power. You will also be paying for reliability.
#10721, "RE: 9.6:1 comp, head gasket handle 300hp?" In response to Reply # 4 May-28-04 04:02 AM by HybriDSM
I hate to do this, but do some more research before you try to take this project on. It sounds a little bit like you are flying by the seat of your pants here. There are alot of intricacies in doing what you are trying to do, so really it's not as simple as just asking us what you need to do. I'm sorry to do this, but I really can't see it being done without alot of knowledge on your part.
9.0:1 is also very high for forced induction engines. I'm guessing to get to the magic 300 number with 9:1 compression, it would take in the neighborhood of 17-20 PSI, but that is a total guess.
Go to dsmtuners and read through their upgrade paths and you'll get a better idea of what you need to do to "just run more boost". It's not as simple as just getting an MBC and turning it up to 22 PSI.
Also, as Jeff said before me, get a turbo engine. They are designed for boost, so don't screw around turboing a non-turbo.
#10723, "RE: 9.6:1 comp, head gasket handle 300hp?" In response to Reply # 7
Originally posted by Remy I have 9.0:1 compression. Matt shut up !! www.cnnmotorsports.com
How do you like tuning it. To be perfectly honest, I have no practical experience with it, but have heard how difficult it is to tune. What say you so far?
it must be nice with quicker boost and more HP per PSI though.
#10724, "RE: 9.6:1 comp, head gasket handle 300hp?" In response to Reply # 8 May-28-04 04:29 AM by burntheblobs
Im talking 9.0:1 JE Forged Pistons..... and please don't tell me to do reseearch. I researched all yesterday and even found that 420a turbo kits can put out 280hp it seems...
1991 Mitsubishi Eclipse GSX - SOLD 2006 Mustang GT Convertible
#10725, "RE: 9.6:1 comp, head gasket handle 300hp?" In response to Reply # 9 May-28-04 04:45 AM by HybriDSM
Originally posted by burntheblobs Im talking 9.0:1 JE Forged Pistons..... and please don't tell me to do reseearch. I researched all yesterday and even found that 420a turbo kits can put out 280hp it seems...
Just get a turbo motor. Honestly, for all the hassle you would endure to put forged internals into the NT block, it would be cheaper and better to get an engine built for a turbo. You can get as full 4G63 engine for 1200 bucks from any number of importers, and the forged pistons and rods you'd have to get to put in your NT would be much much more than that when it's all said and done.
Also, when I mentioned researching, since the 420A and 4G63 engine are ENTIRELY different, comparing what a 420A kit can do is useless.
We want to help, but just spend as much time as you can familiarizing yourself with the engine since it's an entirely new endeavor for you. The more you know off the bat, the more detailed info we can give when you ask specific questions.
