420A What Pistons to use

[DSM DAN]

Ok guys I need some help. My motor (420A) is apart and I'm about to order my pistons. I will be turboing my car in august with the hahn stage 2 kit. I want to run 8.6 because I have found that itis better for turboed engines, but I want to be able to drive my car until august. so should I just run 10.5 or what How does our motors drive with 8.6 pistons without the turbo. Please let me know soon guys because I'm very anxious.

 

[GSGoinFast]

Ok guys I need some help. My motor (420A) is apart and I'm about to order my pistons. I will be turboing my car in august with the hahn stage 2 kit. I want to run 8.6 because I have found that itis better for turboed engines, but I want to be able to drive my car until august. so should I just run 10.5 or what How does our motors drive with 8.6 pistons without the turbo. Please let me know soon guys because I'm very anxious.

the old rule of thumb is 4% for every compression point. so if you dropped to 8.6, you would loose 5.6 chp and 4.8whp roughly. you can run a turbo on 10.5 compression, but its just harder to tune and you cant boost as high. one thing ive been thinking of doing is getting stock compression 9.6:1 forged pistons. you will have to get them custom, but ERT ( http://catalog.exileracing.com/index.php?cPath=215_248_234&osCsid=19781d6d7dcfd3eee4c9c565936ba4aa ) will make them for you. well not make, but order them for you. i'd call them and talk to them if you want to try and go that route. something ive been contemplating, because i personnally wouldnt want to go 10.5:1 compression with a turbo, too little of a margin for error. hope i helped a little

 

[White97eclipse]

How much boost do you eventually want to run? If you want to run Lots o boost, then you need low comp. To me its much better to go low comp also because it makes tunning that much easier. whats 5hp for that much more boost?? but thats just my opinion.

 

[DSM DAN]

How much boost do you eventually want to run? If you want to run Lots o boost, then you need low comp. To me its much better to go low comp also because it makes tunning that much easier. whats 5hp for that much more boost?? but thats just my opinion.

I want to at least run about 15psi daily and about 20-22psi on race days

 

[DSM DAN]

the old rule of thumb is 4% for every compression point. so if you dropped to 8.6, you would loose 5.6 chp and 4.8whp roughly. you can run a turbo on 10.5 compression, but its just harder to tune and you cant boost as high. one thing ive been thinking of doing is getting stock compression 9.6:1 forged pistons. you will have to get them custom, but ERT ( http://catalog.exileracing.com/index.php?cPath=215_248_234&osCsid=19781d6d7dcfd3eee4c9c565936ba4aa ) will make them for you. well not make, but order them for you. i'd call them and talk to them if you want to try and go that route. something ive been contemplating, because i personnally wouldnt want to go 10.5:1 compression with a turbo, too little of a margin for error. hope i helped a little

Thanks man, but will it still drive normaly like no bogging out and also I want to run the crane 0014 turbo cams do you think I still will be able to drive with those also

 

[GSGoinFast]

Thanks man, but will it still drive normaly like no bogging out and also I want to run the crane 0014 turbo cams do you think I still will be able to drive with those also

i assume your talking about the 8.6 compression. well ive never driven it with lower compression and no turbo, but 4.8whp doesnt seem like much to me. its like taking off a cold air intake. as for the cams, yea they will work fine if your not boosting. all it is is the 0012 nitrous intake cam and the 0010 street exhaust cam. should run fine.

 

[DSM DAN]

i assume your talking about the 8.6 compression. well ive never driven it with lower compression and no turbo, but 4.8whp doesnt seem like much to me. its like taking off a cold air intake. as for the cams, yea they will work fine if your not boosting. all it is is the 0012 nitrous intake cam and the 0010 street exhaust cam. should run fine.

Kewl man thanks, I ordered the 8.6

 

[Ajax]

Just saw your post and I have driven my car for a year with the 8:6 pistons and crane 14 cams while i was waiting for the turbo, run fine the whole time. Had my turbo for 2 months and just melted one of my pistons yesterday so its time to buy new ones but I want something diff than JE.

 

[baxsom]

what led to the piston melting

i have wiseco 8.8 to 1 in with the crane #14's and i do not want the same to happen to me

 

[Ajax]

I am sure i was running to lean, which is not my fault since I got the car tuned profesionally. I also dont have a EGT gauge to monitor my temps, but thats the first thing I am putting in after fixing her up. Yeah I was running 12 psi just fine and was curious what it would feel like at 16psi which I cranked it up to with the E-01 did about 3 runs on a back road and started to miss, turned the boost down to go back home and my car did not want to go anywhere and it died. My other pistons are fine-only did a compression check but #4 had 0. And what sucks is that there is only about 5000 miles on the engine and you have to buy all 4 at once so there goes all my money, but I should have some pics up after the weekend for all you guys to laugh at!! How is the venolia pistons DSM Dan looked at their website but I am going to do some more research before I get anything.
PS it could be only the rings that melted but I will know for sure after this weekend

Edit: Just did a search on Venolia and think I might go with them and suggestions on what compression to run, shoul I get them bored over? (dont mean to steal the thread)

 

[GSGoinFast]

I am sure i was running to lean, which is not my fault since I got the car tuned profesionally. I also dont have a EGT gauge to monitor my temps, but thats the first thing I am putting in after fixing her up. Yeah I was running 12 psi just fine and was curious what it would feel like at 16psi which I cranked it up to with the E-01 did about 3 runs on a back road and started to miss, turned the boost down to go back home and my car did not want to go anywhere and it died. My other pistons are fine-only did a compression check but #4 had 0. And what sucks is that there is only about 5000 miles on the engine and you have to buy all 4 at once so there goes all my money, but I should have some pics up after the weekend for all you guys to laugh at!! How is the venoli pistons DSM Dan looked at their website but I am going to do some more research before I get anything.
PS it could be only the rings that melted but I will know for sure after this weekend

wait so you just cranked the boost up to 16 psi while using the fuel maps for that were professionally tuned for 12 psi?? that could be your problem right there

 

[Ajax]

See now this is were I get lost and why I had to learn the hard way. Me and engine stuff= me and fuel stuff = Thats why I got it tuned at a shop, and I asked him does it matter what I set my boost at and he told me everything should be fine and that the e-manage would compensate for any adjustments that i make for boost. So was that wrong bc when it comes to tuning I am a complete dumbass and wish somebody around me can actually show how the stuff works so that I can learn and know what to look for when I make changes like boost.

 

[GSGoinFast]

See now this is were I get lost and why I had to learn the hard way. Me and engine stuff= me and fuel stuff = Thats why I got it tuned at a shop, and I asked him does it matter what I set my boost at and he told me everything should be fine and that the e-manage would compensate for any adjustments that i make for boost. So was that wrong bc when it comes to tuning I am a complete dumbass and wish somebody around me can actually show how the stuff works so that I can learn and know what to look for when I make changes like boost.

i dunno i mean your fpr will add more fuel for the higher boost, but i cant imagine 12psi having the same exact tuning as 16 psi. your getting a hotter intake charge, so i would assume you would want atleast a tad bit more fuel to prevent pre-det... i dunno just my opinion

 

[Ajax]

thats the other thing I dont have an aftermarket fpr since I have a 97 which is the returnless fuel system, and he told me that it should be fine with the walbro fuel pump or is there a stock fpr?

 

[White97eclipse]

Ok wait, youre running 12lbs on a stock fpr???? wow, ive never heard of that before....

Also, from what i know... if you get your car tuned at 12lbs of boost, then you are safe at any setting UP TO 12 lbs. THats why most people tune for like 19lbs of boost and run around 15 daily. not trying to act like i know everything... just givin my .02.....

 

[Ajax]

No I appreciate what you are saying thats the only way I learn is from what everyone else has to say. This really pisses me off since i wanted a fpr and he told me its unnessecery So I should install one next time around which would mean I have to put a line in back to my fuel tank, crap. And here I thought i was finally close to done but that our cars-never done. Well at least it is making it easier to put my clutch in !

 

[White97eclipse]

Well, glad to be of some help. Trust me, i know how it feels to have a never-ending list. But with the FPR, you might want to got like 1:1 if your going the megasquirt way or something like that... or you could just go the good ole big injector with sfmu.. . thats what i have...

 

[Ajax]

Yeah I am running 550's which is plenty big (As you can see I am watching my emails bc I am busy with a research paper and am trying to find anyway not to do it!!!)

 

[GSGoinFast]

thats the other thing I dont have an aftermarket fpr since I have a 97 which is the returnless fuel system, and he told me that it should be fine with the walbro fuel pump or is there a stock fpr?

i think the first thing you need to do is to get a new shop.... fast WTF

this is a prime example as to why i do everything myself... i may not do it right, but i know it works

 

[Ajax]

Yeah not that easy to find a shop when you live in the middle of Iowa or NW Iowa anyways. So that is what you think went wrong. The stock fpr could not keep up? So should I talk to the shop and see what they have to say about this whole ordeal or do I just forget about it and pay for it myself? Should I go with the vortec sfmu? what ratio? I am kinda lost when it comes to fuel! Thanks

 

[GSGoinFast]

Yeah not that easy to find a shop when you live in the middle of Iowa or NW Iowa anyways. So that is what you think went wrong. The stock fpr could not keep up? So should I talk to the shop and see what they have to say about this whole ordeal or do I just forget about it and pay for it myself? Should I go with the vortec sfmu? what ratio? I am kinda lost when it comes to fuel! Thanks

its not that your stock fpr couldnt keep up, it did its job, the problem is you dont have ANY way to raise the fuel pressure according to boost, since the stock fpr doesnt. you probably got away with it because they tuned your big injectors for 12 psi by messing with pulse width alot, therefore you could run the stock fuel pressure and still get enough fuel. but when you raised it up to 16 psi of boost, you were still running the same amount of fuel as you were with 12 psi, and well you see what happened.

first thing you have to do is go to the shop and ask wtf there smoking. next see if you can get 2 of it. after that ask them how there going to fix THERE mistake. if they wont take responsibility for it or are going to charge you to do the work, say thanks, leave and do it yourself. there are few things that you wont be able to do with some basic hand tools and jackstands. get a sfmu.

 

[WHite97RS]

thats the other thing I dont have an aftermarket fpr since I have a 97 which is the returnless fuel system, and he told me that it should be fine with the walbro fuel pump or is there a stock fpr?

A 97 Eclipse RS has no fuel return??????

 

[GSGoinFast]

A 97 Eclipse RS has no fuel return??????

is that sarcasm?? all of the ?? makes me suspicious... well ill just tell you anyway, we have a return line, but it comes from the stock fpr which is back by the tank. we dont have a return line from the rail tho.

 

[Ajax]

Yeah I just send him a nice email dont know what to expect, but I do all my engine work myself anyways but I am still a little affraid of working with the turbo since nobody around me can give me any advice, but I guess the only way you learn is doing it yourself and spend alot of time on dsmtuners!! Any good links on how to install a sfmu on our cars?

 

[GSGoinFast]

Yeah I just send him a nice email dont know what to expect, but I do all my engine work myself anyways but I am still a little affraid of working with the turbo since nobody around me can give me any advice, but I guess the only way you learn is doing it yourself and spend alot of time on dsmtuners!! Any good links on how to install a sfmu on our cars?

http://www.2gnt.com/nuke/modules.php?name=Sections&op=viewarticle&artid=59

http://www.2gnt.com/nuke/modules.php?name=Sections&op=viewarticle&artid=82

what did the email say?