SR20DET Stock internals

[tonis56]

I am currently rebuilding my SR and i am planning on upgrading cams, headgasket, head bolts, turbo, injectors etc. What i am wondering is how much hp can the stock rods and pistons take with the right amount of fuel and a really good tune? Im shooting for around 400 whp. Is this safe or should i go with the extra protection of rods and pistons? ?Thanks in advance.

Tony

[tonis56]

bump it

[1fasts14]

the stock motor can hold 400whp with ease i would upgrade to some 740cc injectors and a walbro 255lph fuel pump, the rods are practically indestrucible better than some aftermarket rods, the pistons are the weak point but with a good tune u will have no problems but i would recommend getting a cometci metal headgasket and some arp head studs, im pretty sure the stock headgasket is good to around 21psi but wouldnt push it hope this helps u out.

thanksmark

[tonis56]

bump for some more opinions. Possibly some dyno sheets!

[180fan]

dyno sheets of what people with blown engines?

[tonis56]

yea sure that might help.

[ILikeMy240sx]

stock headgasket is good for 21 psi??? I dont think so... On a S13 redtop or blacktop with T25, Id say the stock HG is good for about 14 psi if even that.

Id say stay away from cometic HG... From what people say, cometic HGs are very shi!tty made for SR engines but very good for other engines for some reason..

Get either Apexi or Greddy and ARP head studs. I am too rebuilding the engine (stock rebuild) and I am putting in Apexi HG and ARP head studs.

[tonis56]

yea i got a hold of some JUN bolts. I am going to be using either trust or apexi headgasket. What is your hp goal for the stock rebuild.

[virus77]

Ive been running 17 psi from a gt28r on the stock unopenned motor for 10k miles now, I hope she holds up

[luv2spedup]

Ive been running 17 psi from a gt28r on the stock unopenned motor for 10k miles now, I hope she holds up

i guess ur just lucky change that head gasket

[luv2spedup]

u should be fine with 400whp with a stock block

[virus77]

Actually I dont think I'm lucky, I just know my car is tuned. And 400 on the stock pistons is playing with fire, ring lands are bound to break after so much abuse. Its not really the best choice if the car is your daily driver. Taking the step from a 300whp to a 400 whp daily driven car calls for alot of expensive change, make your decision wisely or you will end up throwing money away.

[tonis56]

how about aftermarket pistons with stock rods??

[dsm007]

how about aftermarket pistons with stock rods??

Not a bad idea if your on a budget,but I would recomend to get them shotpeened to add more strength and assurance just in case,magnaflux(I spell that right?),and checked for straightness.

[tonis56]

Not a bad idea if your on a budget,but I would recomend to get them shotpeened to add more strength and assurance just in case,magnaflux(I spell that right?),and checked for straightness.

how much does that usually cost? because i was gonna get some eagle rods, and if its anything close to that price, I think ill just go with the aftermarket rods.Tony-

[180fan]

before posting something like this, start doing your own homework starting with searching.

There have been discussions before about what you get out the factory, pros and cons of different types of rods and pistons and what other people run with how much power they have.

[tonis56]

before posting something like this, start doing your own homework starting with searching.

There have been discussions before about what you get out the factory, pros and cons of different types of rods and pistons and what other people run with how much power they have.

Well, i have searched and have not really found any concrete info. Do you think that some jackass saying that the stock headgasket is going to hold 21 psi is really going to get my vote? This is going to be a daily driven engine and for me to have it ****ed up by some bogus info is not going to be acceptable. This is part of my "homework". If you have nothing constructive to say then dont post in my thread. If i feel the need to search farther into this then i most definatley will. I dont need you to tell me when to do things. Thanks everyone that was able to give me good info.

damn
Modified by tonis56 at 11:48 AM 11/22/2005

[SILVIADRIFTR]

I am currently rebuilding my SR and i am planning on upgrading cams, headgasket, head bolts, turbo, injectors etc. What i am wondering is how much hp can the stock rods and pistons take with the right amount of fuel and a really good tune? Im shooting for around 400 whp. Is this safe or should i go with the extra protection of rods and pistons? ?Thanks in advance.

Tony

If you are still wanting another persons input, here ya go.

1.From my dealings with many sr motors, you can push the motor to around 21 psi for a limited time. It will eventually pop the head gasket and probably sooner than later. 17-19 is the average psi I have seen without damage.2. As in my sig, we were able to get 473whp with a stock bottom end and stock cams. Scott Enthalpy has done a little over 550whp with a stock bottom end and built head. On our 473whp, just by dropping hks 272 step 2's in with no timing adjustments or antilag control we did 525whp.

To answer you questuion from the begining paragraph, the stock pistons and rods can handle up to 570whp(or at least that is the most they have been pushed to that has been reported). The stock head gasket will only handle right at 400whp and at 375 whp will decrese the life of the head gasket very quickly. If you are planning to do any more than 450whp I would go ahead and tear the motor down. I have confered with 2 of the HKS techs that helped engineer the motor in HKS's s15 and their response to anything over 450whp was if it is not a built bottom end it will not last very long which had been their experience with the red s15's motor.Just my .02.

[tonis56]

If you are still wanting another persons input, here ya go.

1.From my dealings with many sr motors, you can push the motor to around 21 psi for a limited time. It will eventually pop the head gasket and probably sooner than later. 17-19 is the average psi I have seen without damage.2. As in my sig, we were able to get 473whp with a stock bottom end and stock cams. Scott Enthalpy has done a little over 550whp with a stock bottom end and built head. On our 473whp, just by dropping hks 272 step 2's in with no timing adjustments or antilag control we did 525whp.

To answer you questuion from the begining paragraph, the stock pistons and rods can handle up to 570whp(or at least that is the most they have been pushed to that has been reported). The stock head gasket will only handle right at 400whp and at 375 whp will decrese the life of the head gasket very quickly. If you are planning to do any more than 450whp I would go ahead and tear the motor down. I have confered with 2 of the HKS techs that helped engineer the motor in HKS's s15 and their response to anything over 450whp was if it is not a built bottom end it will not last very long which had been their experience with the red s15's motor.Just my .02.

Dude you kick ***. You are the reason that I made this thread, to get someone that actually knows what they are talking about and not just tell me what they think they heard from a friend "oh 400whp or so". I am planning on getting a headgasket and also doing the complete head. thank you for the info.

[SILVIADRIFTR]

Dude you kick ***. You are the reason that I made this thread, to get someone that actually knows what they are talking about and not just tell me what they think they heard from a friend "oh 400whp or so". I am planning on getting a headgasket and also doing the complete head. thank you for the info.

No problem. Glad I could help.

[The Mic]

I am currently rebuilding my SR and i am planning on upgrading cams, headgasket, head bolts, turbo, injectors etc. What i am wondering is how much hp can the stock rods and pistons take with the right amount of fuel and a really good tune? Im shooting for around 400 whp. Is this safe or should i go with the extra protection of rods and pistons? ?Thanks in advance.

Tony

zerothread?id=59344

[tonis56]

zerothread?id=59344

Also a nice thread. Thank you all for the good info!

[NY S13 SR]

stock headgasket is good for 21 psi??? I dont think so... On a S13 redtop or blacktop with T25, Id say the stock HG is good for about 14 psi if even that.

Id say stay away from cometic HG... From what people say, cometic HGs are very shi!tty made for SR engines but very good for other engines for some reason..

I have been running 17 psi for 2.5 years, 7500+ miles on the stock head gasket. If you plan over 17-18 psi then changing the head gasket is recommended.

Cometic head gasket is fine, we have sold hundreds with not one return. Greddy on the other hand, one of my friends now refuses to use them due to several similar problems on different engines involving oil leaks / poor sealing. Power Enterprise makes good MHG's also.

_______________________Jeff Hhttp://www.heavythrottle.com

[ca18det_boy]

I have a completely built bottom end, stock HG and I'm doing just fine at 25psi on a T4. The way I see it I would rather blow a HG then something else thats a little more important. Its all about fuel and tuning, do it right and it will last you awhile. Just stay away from that piggy back crap.

[tonis56]

thank you guys both. I just purchased a grex headgasket hopefully i dont have those probs that jeff's buddy had. Im going to contact my local machine shop this week and see what they can do as far as cryo or shotpeen. I might even get some work dont on the crank. As far as engine managenent, i definatley wont use a piggy back, but I still havent made any decisions.

Tony-

[bdrifta]

If your doin 400hp as a goal...don't slack off on the bottom end. im sure that the sr is rated to handle that(its a damn amazing engine)...but why take the chance?

Cheap, Powerful, Reliable...pick two.

besides if you throw a rod or anything like that...your fu**ed, rebuild here you come.

[dsm007]

Us

how much does that usually cost? because i was gonna get some eagle rods, and if its anything close to that price, I think ill just go with the aftermarket rods.Tony-

usually it could be anywhere from $100 to $200 for that service,depends,if your good friends with the guy at the machine shop he might charge you only $50 or do it free....just call some machine shops for price quotes or ask around with local engine builders and performance mechanics shops......by the way check the bore on the big end of those eagle rods with a bore micrometer to make sure they are pefectly round inside....not saying they are bad rods to buy cause I heard they run pretty good but just make sure when you get a set because some people have run into them being out of round on the big end.

[tonis56]

Ususually it could be anywhere from $100 to $200 for that service,depends,if your good friends with the guy at the machine shop he might charge you only $50 or do it free....just call some machine shops for price quotes or ask around with local engine builders and performance mechanics shops......by the way check the bore on the big end of those eagle rods with a bore micrometer to make sure they are pefectly round inside....not saying they are bad rods to buy cause I heard they run pretty good but just make sure when you get a set because some people have run into them being out of round on the big end.

Ill definatley look in to this!thank you

[mackdaddy240]

You sound like you know what your talking about but, I heard that the stock T25 can only handle about 15psi without overheating, so I dont see how you can run 17-19 safely when the turbo isnt capable. Do you have any more detailed info, fuel pressure, injector size, stock ecu? SAFC? Wastegate, spark gap? I just got my sr20 running its stock, besides header, and downpipe. So I am "doing my homework" any info would help I'm on a budget whats the most you can get out of stock turbo, with say bigger injectors 255lph fuel pump, adjustable fuel pump regulator, and a boost controler? Also if you buy a boost controler and still have the stock internal wasetgate, Can you bypass the wastegate somehow or do you have to remove it and install a adjustable one?Let me know I would really appreciate any info.

If you are still wanting another persons input, here ya go.

1.From my dealings with many sr motors, you can push the motor to around 21 psi for a limited time. It will eventually pop the head gasket and probably sooner than later. 17-19 is the average psi I have seen without damage.2. As in my sig, we were able to get 473whp with a stock bottom end and stock cams. Scott Enthalpy has done a little over 550whp with a stock bottom end and built head. On our 473whp, just by dropping hks 272 step 2's in with no timing adjustments or antilag control we did 525whp.

To answer you questuion from the begining paragraph, the stock pistons and rods can handle up to 570whp(or at least that is the most they have been pushed to that has been reported). The stock head gasket will only handle right at 400whp and at 375 whp will decrese the life of the head gasket very quickly. If you are planning to do any more than 450whp I would go ahead and tear the motor down. I have confered with 2 of the HKS techs that helped engineer the motor in HKS's s15 and their response to anything over 450whp was if it is not a built bottom end it will not last very long which had been their experience with the red s15's motor.Just my .02.

[SILVIADRIFTR]

You sound like you know what your talking about but, I heard that the stock T25 can only handle about 15psi without overheating, so I dont see how you can run 17-19 safely when the turbo isnt capable. Do you have any more detailed info, fuel pressure, injector size, stock ecu? SAFC? Wastegate, spark gap? I just got my sr20 running its stock, besides header, and downpipe. So I am "doing my homework" any info would help I'm on a budget whats the most you can get out of stock turbo, with say bigger injectors 255lph fuel pump, adjustable fuel pump regulator, and a boost controler? Also if you buy a boost controler and still have the stock internal wasetgate, Can you bypass the wastegate somehow or do you have to remove it and install a adjustable one?Let me know I would really appreciate any info.

I was answering the initial question about stock internals not all the other things involved with running that much boost. My rule of thumb is 10psi on t25 or larger 255 walboro. The turbo will only handle around 14-15 psi safely. You can run a stock ecu, safc or greddy emanage, minimum gt25r, 550 injectors, FMIC,downpipe and exhaust, and blow thru maf, and get 340whp at around 18psi. With an aftermarket long tube manifold and a t3/t4 you can put down the same amount of horsepower at around 13psi(I have a dyno sheet if anyone needs to se it). And it goes up from there. The safc is only good with, up to , 550cc inj. anything bigger will need a greddy emanage up to 650cc and anything above that you will need to do a chipped ecu or a standalone(I prerfer the EMS). Did that answer your questions?

EDIT* Also I have seen factory rails and factory fuel pressure regulators handle up to 500whp. Ask Enthalpy, I believe he has done it as well.