Matadem Posted November 30, 2007 Share Posted November 30, 2007 Since the F54 block I have has some grooves/ scratches in it the machine shop recommended to go OS 0.030 So I contacted brc pistons they told me to go 8.0 to 1 or 8.3 to 1 CR What is your opinion on cr regarding a turbo motor Since I spend allot of money into the head and now for pistons might as well shoot for 400hp I have shaved the head (p90) 0.005 just to be sure it is perfect and I also want to do it to the block... I do have an intercooler and I am going also with water/meth injection I also asked them for lighweight the pistons.... any opinions/ suggestions/ recomendations? Thanks Quote Link to comment Share on other sites More sharing options...
Dragonfly Posted November 30, 2007 Share Posted November 30, 2007 Non turbo guy here but IMO if you want to get 400hp out of this engine and know that it will not fall apart the first time you drive it, here is what I suggest: Layout your goals, your money and your time to completion. Print out an engine blueprint check sheet, a series of turbo data sheets for any turbos that are in the power rating you want and cam specs for any cam that is advertised in the range of your goals. Start crunching numbers... You should build the entire thing on paper before you ever buy the first part you do not already have. If you do this it will save you time, money and lots of questions that people will tell you to research prior to asking. There is a ton of info on this site and it is a great place to start your research but you should have true/realistic/atainable goals before you start asking to many questions. Dragonfly Quote Link to comment Share on other sites More sharing options...
Matadem Posted November 30, 2007 Author Share Posted November 30, 2007 The only question I ask here in my post is regarding the cr I think the holset turbo I have is enough for that goal as well as the head... including the fuel pump and regulator that I have so even with forged pistons arp fasteners on rods, mains ,head and balanced bottom end it is unrealistic it was 400hp not 1400hp sure it can blow up everything is a possibility funny thing how a friend of mine can have near 300rwhp out of a bone stock 1.8l engine just by changing to microtech ems, ic , turbo etc... notice the brand of the ic btw he's in the 11's now http://www.dragtimes.com/Mitsubishi-Lancer-Timeslip-10722.html Quote Link to comment Share on other sites More sharing options...
PETEW Posted December 1, 2007 Share Posted December 1, 2007 It just depends on what you are looking to achieve. There are a bunch of guys with 8 to 1 compression ratios that are in the 400 hp range. The main reason you would go higher on compression is that you are looking for a car that has a little oomph when not on the boost. You also have to realize that the higher the compression the more chance you have of detenation with large amounts of boost. You gotta remember that out engines are 25 years old and very out of date compared to a Honda motor. I think your RWHP number is achievable with either piston. But that is only my opinion, others may feel (or know) different. Quote Link to comment Share on other sites More sharing options...
vegasnative Posted December 1, 2007 Share Posted December 1, 2007 what octane our you going to run? Quote Link to comment Share on other sites More sharing options...
Dragonfly Posted December 1, 2007 Share Posted December 1, 2007 The only question I ask here in my post is regarding the cr I think the holset turbo I have is enough for that goal as well as the head... including the fuel pump and regulator that I have so even with forged pistons arp fasteners on rods, mains ,head and balanced bottom end it is unrealistic it was 400hp not 1400hp sure it can blow up everything is a possibility funny thing how a friend of mine can have near 300rwhp out of a bone stock 1.8l engine just by changing to microtech ems, ic , turbo etc... notice the brand of the ic btw he's in the 11's now http://www.dragtimes.com/Mitsubishi-Lancer-Timeslip-10722.html Not trying to give you a hard time at all, I am just trying to let you know in my own way that you will get more answers and better input if the question(s) you ask are more thought out (or researched) such as: I would like to get 400rwhp out of my L28ET, I have been researching turbos and compretion ratios but I am not sure what cr to run since I will be using pump gas, does anyone have any suggestions of what cr I should have my forged pistons made to? With the question like that you will probably be asked what type of turbo you are going to use what the a/r is and what octane fuel is available to you. Any way as I think about this I may be off base with what I am telling you but I have never been much for limited information questions as they always lead to limited information answers which almost always cost you more money and time. BTW your goals are very realistic but at the same time all the people I know personaly who run 400 or more RWHP with L series engines have trouble with their "streetability" and end up using them on a very limited basis. One last thing from me... the lower the cr you run the higher the boost you can run and boost = HP, but as mentioned above you loose off boost performance with a lower cr. Dragonfly Quote Link to comment Share on other sites More sharing options...
Tony D Posted December 1, 2007 Share Posted December 1, 2007 BTW your goals are very realistic but at the same time all the people I know personaly who run 400 or more RWHP with L series engines have trouble with their "streetability" and end up using them on a very limited basis.Dragonfly Oh dude, you're crucifying me for 25-30 HP?!?!?!?!?!? My dyno runs were only 17psi, I'm sure I was closer to 400 at 21-22psi, I just never verified it on the dyno... The old 'Shark Car' was daily driven with a Blowthrough Carb setup. And it was an N/A with 8.5:1 CR with a JDM N42 head/block... My drivability problems came after I stupidly changed the design for my plenum from something that was working, but hitting the hood lightly, to something that 'looked cooler'....BIG Mistake. I stopped driving it because I wanted to freshen up the car after 10 years of beating on it almost daily...put on some EFI, etc... Then 'Life Happened' and it sits, resting, waiting for the day I return to it with wrench in hand, ready to ressurect it. I'm not sure how well you know JeffP, I know he has commented on how nice your car is, and his car is well above that HP level and is really streetable. Totally. He'd drive it daily if he'd get the EMS system sorted out, but for daily drivability it's easily doable. That aside, to the question at hand: CR. Either is acceptable. If they have to dish the head to give you 8:1, MAKE SURE they replicate the combustion chamber in the crown of the piston, as you want that flat quench area in there if at all possible. My guess is 8 and 8.3 are their standard cuts, and that is why they 'suggested them'. The CR will depend on what Combustion chamber you currently have. If you 'spent a lot of money on the head already' then I can only ASSUME that the combustion chambers were welded and reshaped for higher quench and proper fastburn design---in which case 8.5:1 would not be untoward at only 400 HP. And if you are running Alky Injection...then the CR could be much higher as it really slows down the burn and cools it all down, preventing detonation with setups that would never live at the levels people drive them to. A Smarter idea is to build the bottom end to accomodate the power level WITHOUT the alky, and then use it as a detonant supressor for standard pump gas. That way if your tank has run out for the evening, you can simply knock off a pound of two of the boost, and drive home without worrying the thing will detonate when you get into boost the next time up the long hill home. Quote Link to comment Share on other sites More sharing options...
Dragonfly Posted December 2, 2007 Share Posted December 2, 2007 Oh dude, you're crucifying me for 25-30 HP?!?!?!?!?!? My dyno runs were only 17psi, I'm sure I was closer to 400 at 21-22psi,[/Quote]Yea Tony I know... but you know when I say streetable I am talking about consistantly. We both know that most people who run that kind of power turn it down most of the time, I am going on the assumption that Matadem wants to run consistantly at 400 or above (reading between the lines). I just never verified it on the dyno... The old 'Shark Car' was daily driven with a Blowthrough Carb setup. And it was an N/A with 8.5:1 CR with a JDM N42 head/block... My drivability problems came after I stupidly changed the design for my plenum from something that was working, but hitting the hood lightly, to something that 'looked cooler'....BIG Mistake. I stopped driving it because I wanted to freshen up the car after 10 years of beating on it almost daily...put on some EFI, etc... Then 'Life Happened' and it sits, resting, waiting for the day I return to it with wrench in hand, ready to ressurect it.[/Quote]Youv'e got to remember that over 99% of the time you are the exception to the rule... you have more knowledge and secret mojo in your head than Bill Gates has money . I'm not sure how well you know JeffP, I know he has commented on how nice your car is, and his car is well above that HP level and is really streetable. Totally. He'd drive it daily if he'd get the EMS system sorted out, but for daily drivability it's easily doable. I've only met Jeff once and I do feel that he has the most impressive L powered Z on the planet, but again we both know that Jeff has enough money in that car to buy a house in the midwest (he just won't admit it out loud anymore). The other thing about Jeffs car is he has done virtualy everything that I suggested in my first post on this thread - he designed, engineered and built that engine in his head and on paper before he started turning wrenches. Yea Tony your right but I was just trying to make a point to Matadem that if he doesn't do the planing and the studying first about how everything in the engine will work together he will have an extremely slim chance of having a legitamit 400 RWHP car and even slimmer chance that it will be streetable enough to use as a daily driver (daily driver part is a guess because he never said what he wants to use the car for). Dragonfly Quote Link to comment Share on other sites More sharing options...
Tony D Posted December 2, 2007 Share Posted December 2, 2007 Yeah, the big number IMO is around 350. If you plan on running track days and making more than 300-350 getting beefier stuff inside is a good plan. Below that, and with less track use, it's like 'double-secret probation'---you're the only one that knows it's in there, and until something goes 'boom' nobody else will ever know, either. Most of Jeff's money is because he did that over the course of 20+ years. When taken in that light, and the fact that he recorded the thing scrupulously so he actually KNOWS how much he spent (including the original purchase price of the vehicle, as well as a major crash repair) the costs really aren't out-of-line with what the majority of the people here have spent really. It works out to around $2500 a year, give or take for years where things went 'crunch', 'Snap', or 'Boom'---to that, even myself, I must plead "Guilty"...and given how good his look, and how crappy mine look, that doesn't bode well for my cosmetic asthetic! LOL (Come to think of it, Pal Pal says I have 'reached my spending limit' which apparently is $10K...WTF? That couldn't be right....) Quote Link to comment Share on other sites More sharing options...
Matadem Posted December 2, 2007 Author Share Posted December 2, 2007 One thing I don't care about streetability this won't be a daily will be driven to the track and very limited street use the car isn't a z but a bluebird 2 door stripped that going to be painted flat black with weld rims mad max style Thanks for the suggestions. Quote Link to comment Share on other sites More sharing options...
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