So..I put OEM SR20DE 9.5:1 pistons in my SR20DET... - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

kovert240sx · 04-23-2014, 11:39 AM

So to be honest..It wasn't intentional, but interesting that it kinda worked anyway.

A couple years back i had a machine shop do the assembly on a rebuild and they said they could also order the factory pistons.

Without thinking what that meant, I went ahead with it. ( I intended to put factory DET pistons in it ).

After the engine was complete I had it dyno tuned on a mustang dyno with the following:

Stock rods
Stock injectors
Stock fuel system aside from Z32 filter / walbro pump, also stock fuel pressure.
Stock intake manifold.
Nistune
HKS GT2510
256/256 cams
Tubular bottom mount manifold w/ full exhaust
91 octane gas @ 17psi

Results:

366whp / 310ft lbs tq

I was maxing out the injectors so the low boost = low tq.

I ended up having my drain plug back itself out on the dyno that day, lost all oil and killed the turbo.

fast forward 2 years: at some point during a injector upgrade/turbo swap, or maybe even the same day I killed the turbo..my ( DET ) piston rings are toast.

Pulled the head yesterday and discovered my mistake from the build.

Even though it wasn't intentional, i figured I'd share anyway as I've never heard of it being attempted.

jr_ss · 04-23-2014, 11:43 AM

People put high comp pistons in all the time, perhaps not our motors, but it's not unheard of.

kovert240sx · 04-23-2014, 11:47 AM

Quote:

Originally Posted by jr_ss

People put high comp pistons in all the time, perhaps not our motors, but it's not unheard of.

Obviously, but I had never heard of anyone using SR20DE oem pistons in a DET.

hobbs · 04-23-2014, 11:54 AM

Not like the B/P chassis guys have been putting turbos on their DEs for the last 20 years. You must be the first one ever to do this.

kovert240sx · 04-23-2014, 11:57 AM

Quote:

Originally Posted by hobbs

Not like the B/P chassis guys have been putting turbos on their DEs for the last 20 years. You must be the first one ever to do this.

holy shit, did you even read my last comment?

hobbs · 04-23-2014, 12:09 PM

Quote:

Originally Posted by kovert240sx

holy shit, did you even read my last comment?

I did but can't seem to care. Again, putting 9:5:1 compression pistons in any SR20 has been done for the last 20 years, you've done something that thousands of other people have done, wooo!

kovert240sx · 04-23-2014, 12:11 PM

Quote:

Originally Posted by hobbs

I did but can't seem to care. Again, putting 9:5:1 compression pistons in any SR20 has been done for the last 20 years, you've done something that thousands of other people have done, wooo!

You can't seem to care that you're avoiding my point all together?

Lets recap for the dunce: OEM high comp NA pistons in a DET - I've yet to see done once, let alone THOUSANDS of times.

hobbs · 04-23-2014, 12:23 PM

Quote:

Originally Posted by kovert240sx

Lets recap for the dunce

I sure am, although you can't seem to grasp the concept that 9:5:1 is the same CR whether it be in a DET block or DE block and will make the same power regardless which block it is in. So yes, your DET with DE pistons will make the same power as a DE with DE pistons with the same mods.

The fact that DET's have oil squirters and sodium filled exhaust valves does not affect the compression radios and thus will not affect the power output like a higher compression would.

But since you really want to have the title of being the first one of putting DE pistons in a DET, go for it, I won't tell anyone you're 20 years late to the party.

kovert240sx · 04-23-2014, 12:54 PM

Quote:

Originally Posted by hobbs

I sure am, although you can't seem to grasp the concept that 9:5:1 is the same CR whether it be in a DET block or DE block and will make the same power regardless which block it is in. So yes, your DET with DE pistons will make the same power as a DE with DE pistons with the same mods.

The fact that DET's have oil squirters and sodium filled exhaust valves does not affect the compression radios and thus will not affect the power output like a higher compression would.

But since you really want to have the title of being the first one of putting DE pistons in a DET, go for it, I won't tell anyone you're 20 years late to the party.

I could care less about a title, or being the "first". My intention wasn't to turn this into some cool guy pissing contest.

kruked · 04-25-2014, 12:48 PM

Quote:

Originally Posted by kovert240sx

I could care less about a title, or being the "first". My intention wasn't to turn this into some cool guy pissing contest.

Can I join the pissing contest? I like setting records.

Dboyizmlg · 04-25-2014, 01:28 PM

Wait a second... You made 366whp on a mustang dyno with STOCK INJECTORS!?
I find that very hard to believe!

5280VertDET · 04-25-2014, 01:36 PM

Quote:

Originally Posted by Dboyizmlg

Wait a second... You made 366whp on a mustang dyno with STOCK INJECTORS!?
I find that very hard to believe!

Maybe 266? Sounds more likely. On my FWD JDM SR20DET with 370s & T25 I made 249...

RalliartRsX · 04-25-2014, 01:56 PM

Those stock injectors (assuming 370cc) run out of physical flow around 250WHP.

They are not PHYSICALLY capable of 366WHP

And also, how the hell are you making more than 300WHP on a T25 based turbo??

Da Fuq?!?! I think Hobbs not caring is the fact that he also smells bullshit in your storyline...........

Dboyizmlg · 04-25-2014, 02:00 PM

Quote:

Originally Posted by RalliartRsX

Those stock injectors (assuming 370cc) run out of physical flow around 250WHP.

They are not PHYSICALLY capable of 366WHP

And also, how the hell are you making more than 300WHP on a T25 based turbo??

Da Fuq?!?! I think Hobbs not caring is the fact that he also smells bullshit in your storyline...........

^^ my point exactly.

Frank_Jaeger · 04-25-2014, 02:50 PM

Quote:

Originally Posted by Dboyizmlg

Wait a second... You made 366whp on a mustang dyno with STOCK INJECTORS!?
I find that very hard to believe!

It doesn't say what injectors he has, only that he's maxing them out. Reading comprehension.

EDIT: Nevermind I fail. It definitely says stock injectors. DE Pistons are magic.

hobbs · 04-25-2014, 03:42 PM

Quote:

Originally Posted by RalliartRsX

Those stock injectors (assuming 370cc) run out of physical flow around 250WHP.

They are not PHYSICALLY capable of 366WHP

And also, how the hell are you making more than 300WHP on a T25 based turbo??

Da Fuq?!?! I think Hobbs not caring is the fact that he also smells bullshit in your storyline...........

It was more the fact that this guy thinks hes the first one to do a 9:5:1 build, his mod list is even more a joke when you look at the posted numbers.

Def · 04-25-2014, 04:13 PM

Quote:

Originally Posted by RalliartRsX

Those stock injectors (assuming 370cc) run out of physical flow around 250WHP.

They are not PHYSICALLY capable of 366WHP

And also, how the hell are you making more than 300WHP on a T25 based turbo??

Da Fuq?!?! I think Hobbs not caring is the fact that he also smells bullshit in your storyline...........

Injectors obviously make this BS. You will be close to maxing out 550 cc injectors at that power level on E10.

But the HKS GT2510 is essentially a stock S14/S15 'T28' aka GT2560R. It can do 300 rwhp with the wick turned up, even on stock cams.

A GT2871R is still a "T25 based turbo" and it'll do over 400 rwhp when pushed really hard.

hobbs · 04-25-2014, 04:21 PM

Quote:

Originally Posted by Def

A GT2871R is still a "T25 based turbo" and it'll do over 400 rwhp when pushed really hard.

Actually it's not, it's a T2 biased turbo, the T2 housing was around before the T25 series came out. Just because it can be made to fit a T2 housing does not mean anything, considering the T25 and GT2871R have very little in common other than it can be mated to the same exhaust housing flange.

RalliartRsX · 04-25-2014, 05:09 PM

I see what both Hobbs and Def are saying

Def, Me as well as yourself know if we look at the compressor maps for what is essentially a glorified T28, it would refute his statements IMMEDIATELY..........but since people (especially the original poster) on here have NO EFFING CLUE on what those are, I kept it simple for the masses

For the masses: At 366WHP, that is 400+ Crank HP, and not many "T2" framed turbos are capable of that type of flow, ESPECIALLY this turbo.

This scenario right here is why Zilvia is such a shit show.........

zerodameaon · 04-25-2014, 08:01 PM

Someone got caught with their hand in the bullshit jar.

*!Zar!* · 04-25-2014, 09:26 PM

I heard we were whipping out dicks?

cotbu · 04-25-2014, 10:29 PM

Quote:

Originally Posted by !Zar!

I heard we were whipping out dicks?

Is it that time of the year already!
Dicks out, In April!

Dboyizmlg · 04-26-2014, 12:56 AM

His entire mod list is screwed up!

OP there is no way you can make those numbers on a MUSTANG DYNO with the list you posted.

Why did you make this thread!?
Troll? Or are you really lacking some knowledge?

kovert240sx · 04-26-2014, 12:58 AM

First of all, Hobbs and def and rally whatever the fuck.. You guys are fucking idiots. Period.

Injectors are rated based on fuel pressure. Increasing that pressure increases flow. Any dip ship knows this. So to claim that 370s are not capable of flowing whatever bullshit number you pulled out of your ass proves my first point.

Second, whichever one of you idiots claimed t2 based turbos cant make 400hp. FYI t25 and t28 are BOTH t2 turbos!

Look at a fucking compressor map...pretty simple to figure out you have no fucking clue what your talking about.

If you want to have fun by jumping all over anyone with a low post count, be my guest, but at least have a slight clue what your saying first.

And to reiterate my reason for posting..this car was running oem sr20de pistons. I can't seem to get that across, OEM DE 9.5:1 Pistons!

Obviously you can get a plethora of aftermarket high comp pistons, my point was that I had never heard of these being used in a DET! And wanted to share my results, fuck me for trying to share.

I could give a fuck less if you guys thinking I'm bullshitting, It's no wonder why I stayed on FA before it went to shit.

You fuckin drift douches have bumped your heads too much, I've got dyno sheets and time slips to prove my claims, you guys can keep your bs knowledge and enjoy your group fuck session spewing with stupidity.

kovert240sx · 04-26-2014, 01:24 AM

And to clarify, I know that 366 sounds high for stock fuel pressure as my old car I had to crank it to supply enough fuel for 362whp. That was also the point of my post. Unless my 370s were remand in Japan and my kvalue ( calculated for 370/z32 maf ) magically worked with 11.5 afrs they are stock 370s and my hunch is the jump from 8.5 to 9.5 comp really makes that big of a difference in expected hp.

Also, my hks turbo was purchased used with its ID plate unreadable, I bought it as a 2510 but it obviously could have been any variation of a hks t2 flanged/ internally gated turbo.

zerodameaon · 04-26-2014, 01:51 AM

I just ran the numbers, you mean to tell me you are running 180 psi for your fuel pressure? Because that is what your above post about more psi = more power just said. That is at 90% duty cycle, at 100% duty cycle you would still be looking at 145 psi. Fun fact, 180 psi is about half way to the pressures found in a top fuel dragster fuel system, I am sure your SR20 is demanding that.

kovert240sx · 04-26-2014, 02:09 AM

Quote:

Originally Posted by zerodameaon

I just ran the numbers, you mean to tell me you are running 180 psi for your fuel pressure? Because that is what your above post about more psi = more power just said. That is at 90% duty cycle, at 100% duty cycle you would still be looking at 145 psi. Fun fact, 180 psi is about half way to the pressures found in a top fuel dragster fuel system, I am sure your SR20 is demanding that.

Lol!
Lets ignore that most nissan 370s have been known to flow closer to 415cc..

[email protected] = [email protected]

Calculation for required cc for 380bhp is 442cc at 0.60 bsfc / 80psi

Not sure where you're getting this nonsense, but you can sit down now.

zerodameaon · 04-26-2014, 02:25 AM

A very bad calculator which I forgot was not very accurate. Anyways I have moved on to two others and those ones agree your numbers still fall short. You would still need to be running 120+ psi to get your power with those injectors. Attached are my sources this time, where is yours? Or is that what your power numbers were, just guesstimates?

Disclaimer, I did mess up those numbers but it was not going to benefit you any if I corrected them. I did not see that the HP numbers on those calculators are engine HP and not wheel.

EDIT: Yes fuck you for sharing. lol Anyways it would have been all cool and no one would have torn your thread to bits if you had just not lied about what you really have going on. People would have thought it was a good cheap way to get a few HP but when you claimed unicorns it was all going to go to hell.

kovert240sx · 04-26-2014, 02:41 AM

Quote:

Originally Posted by zerodameaon

A very bad calculator which I forgot was not very accurate. Anyways I have moved on to two others and those ones agree your numbers still fall short. You would still need to be running 120+ psi to get your power with those injectors. Attached are my sources this time, where is yours? Or is that what your power numbers were, just guesstimates?

Disclaimer, I did mess up those numbers but it was not going to benefit you any if I corrected them. I did not see that the HP numbers on those calculators are engine HP and not wheel.

Hey Genius, Your calculators are using 43.5 as fuel pressure.

I think you're done here, Mr. top fuel.

Run along.
http://www.rceng.com/technical.aspx

zerodameaon · 04-26-2014, 03:01 AM

Oh I am not through with you yet, you are a straight up fucking moron, if you had a 640cc injector at 43.5 and you pumped it up to 120psi you would be looking at over 1000CC.

That is the required static flow rate, now if you go to the bottom of the page you get a nice little fuel flow calculator, where you can put in the old PSI and new PSI along with the old injector flow rate and it calculates you out a nice new flow rate at the higher PSI.

Now please tell me where I fucked up this time. Your calculator gives me almost the same info... shocking

For the sake of consistency I used 366 as the crank HP and 90% duty cycle.

04-23-2014, 11:39 AM	#1
kovert240sx Join Date: Feb 2004 Location: utah Posts: 32 Trader Rating: (0) Feedback Score: 0 reviews	So..I put OEM SR20DE 9.5:1 pistons in my SR20DET... So to be honest..It wasn't intentional, but interesting that it kinda worked anyway. A couple years back i had a machine shop do the assembly on a rebuild and they said they could also order the factory pistons. Without thinking what that meant, I went ahead with it. ( I intended to put factory DET pistons in it ). After the engine was complete I had it dyno tuned on a mustang dyno with the following: Stock rods Stock injectors Stock fuel system aside from Z32 filter / walbro pump, also stock fuel pressure. Stock intake manifold. Nistune HKS GT2510 256/256 cams Tubular bottom mount manifold w/ full exhaust 91 octane gas @ 17psi Results: 366whp / 310ft lbs tq I was maxing out the injectors so the low boost = low tq. I ended up having my drain plug back itself out on the dyno that day, lost all oil and killed the turbo. fast forward 2 years: at some point during a injector upgrade/turbo swap, or maybe even the same day I killed the turbo..my ( DET ) piston rings are toast. Pulled the head yesterday and discovered my mistake from the build. Even though it wasn't intentional, i figured I'd share anyway as I've never heard of it being attempted. __________________ 406hp/385tq- [email protected] Hatch(old) 599hp/454tq- [email protected]??? Coupe(new)

04-23-2014, 11:43 AM	#2
jr_ss Post Whore! Join Date: Dec 2005 Location: Pa Posts: 6,052 Trader Rating: (34) Feedback Score: 34 reviews	People put high comp pistons in all the time, perhaps not our motors, but it's not unheard of. __________________ My SR20VET

04-25-2014, 09:26 PM	#21
!Zar! Premium Member Join Date: Nov 2004 Location: North Korea Posts: 14,576 Trader Rating: (27) Feedback Score: 27 reviews	I heard we were whipping out dicks? __________________

04-26-2014, 12:58 AM	#24
kovert240sx Join Date: Feb 2004 Location: utah Posts: 32 Trader Rating: (0) Feedback Score: 0 reviews	First of all, Hobbs and def and rally whatever the fuck.. You guys are fucking idiots. Period. Injectors are rated based on fuel pressure. Increasing that pressure increases flow. Any dip ship knows this. So to claim that 370s are not capable of flowing whatever bullshit number you pulled out of your ass proves my first point. Second, whichever one of you idiots claimed t2 based turbos cant make 400hp. FYI t25 and t28 are BOTH t2 turbos! Look at a fucking compressor map...pretty simple to figure out you have no fucking clue what your talking about. If you want to have fun by jumping all over anyone with a low post count, be my guest, but at least have a slight clue what your saying first. And to reiterate my reason for posting..this car was running oem sr20de pistons. I can't seem to get that across, OEM DE 9.5:1 Pistons! Obviously you can get a plethora of aftermarket high comp pistons, my point was that I had never heard of these being used in a DET! And wanted to share my results, fuck me for trying to share. I could give a fuck less if you guys thinking I'm bullshitting, It's no wonder why I stayed on FA before it went to shit. You fuckin drift douches have bumped your heads too much, I've got dyno sheets and time slips to prove my claims, you guys can keep your bs knowledge and enjoy your group fuck session spewing with stupidity. __________________ 406hp/385tq- [email protected] Hatch(old) 599hp/454tq- [email protected]??? Coupe(new) Last edited by kovert240sx; 04-26-2014 at 02:20 AM..

04-26-2014, 01:24 AM	#25
kovert240sx Join Date: Feb 2004 Location: utah Posts: 32 Trader Rating: (0) Feedback Score: 0 reviews	And to clarify, I know that 366 sounds high for stock fuel pressure as my old car I had to crank it to supply enough fuel for 362whp. That was also the point of my post. Unless my 370s were remand in Japan and my kvalue ( calculated for 370/z32 maf ) magically worked with 11.5 afrs they are stock 370s and my hunch is the jump from 8.5 to 9.5 comp really makes that big of a difference in expected hp. Also, my hks turbo was purchased used with its ID plate unreadable, I bought it as a 2510 but it obviously could have been any variation of a hks t2 flanged/ internally gated turbo. __________________ 406hp/385tq- [email protected] Hatch(old) 599hp/454tq- [email protected]??? Coupe(new)

04-23-2014, 11:54 AM	#4
hobbs Nissanaholic! Join Date: Aug 2010 Location: Under a rock Posts: 2,263 Trader Rating: (43) Feedback Score: 43 reviews	Not like the B/P chassis guys have been putting turbos on their DEs for the last 20 years. You must be the first one ever to do this.

04-25-2014, 01:28 PM	#11
Dboyizmlg Nissanaholic! Join Date: Aug 2011 Location: SoCal (I.E.), San Berdino, Colton, Redlands Posts: 1,665 Trader Rating: (17) Feedback Score: 17 reviews	Wait a second... You made 366whp on a mustang dyno with STOCK INJECTORS!? I find that very hard to believe!

04-25-2014, 01:56 PM	#13
RalliartRsX Post Whore! Join Date: Apr 2006 Location: Maryland Posts: 4,753 Trader Rating: (32) Feedback Score: 32 reviews	Those stock injectors (assuming 370cc) run out of physical flow around 250WHP. They are not PHYSICALLY capable of 366WHP And also, how the hell are you making more than 300WHP on a T25 based turbo?? Da Fuq?!?! I think Hobbs not caring is the fact that he also smells bullshit in your storyline...........

04-25-2014, 05:09 PM	#19
RalliartRsX Post Whore! Join Date: Apr 2006 Location: Maryland Posts: 4,753 Trader Rating: (32) Feedback Score: 32 reviews	I see what both Hobbs and Def are saying Def, Me as well as yourself know if we look at the compressor maps for what is essentially a glorified T28, it would refute his statements IMMEDIATELY..........but since people (especially the original poster) on here have NO EFFING CLUE on what those are, I kept it simple for the masses For the masses: At 366WHP, that is 400+ Crank HP, and not many "T2" framed turbos are capable of that type of flow, ESPECIALLY this turbo. This scenario right here is why Zilvia is such a shit show.........

04-26-2014, 12:56 AM	#23
Dboyizmlg Nissanaholic! Join Date: Aug 2011 Location: SoCal (I.E.), San Berdino, Colton, Redlands Posts: 1,665 Trader Rating: (17) Feedback Score: 17 reviews	His entire mod list is screwed up! OP there is no way you can make those numbers on a MUSTANG DYNO with the list you posted. Why did you make this thread!? Troll? Or are you really lacking some knowledge?

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