Forged pistons for 250 whp track car?
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Forged pistons for 250 whp track car?
So after a lot of set backs I am finally getting ready for turbo. I have decided Gtx2867r for my b18c gsr. Now I know that stock internals will support around 300 whp but most of the stock internal builds seem to be for fun/daily with no track abuse. So should I build the bottom end with forged rods/pistons or leave it alone? I know a factor in reliability is in the tune but my goals aren't too crazy and not sure if built block is necessary. I am going to run some hill climbs and track days (hopefully start working on competition license).
Also, if I do build the bottom, should I do valve springs/retainers? I will be using stock cams for now. Any into is helpful. Thanks!
Also, if I do build the bottom, should I do valve springs/retainers? I will be using stock cams for now. Any into is helpful. Thanks!
#2
I would go ahead and build a forged bottom end for reliabilities sake. If youre staying with the stock rev limit and stock cams then stock springs etc will be fine.
Btw for only 250hp wont a gtx2860r be a better choice?
Btw for only 250hp wont a gtx2860r be a better choice?
#3
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Re: Forged pistons for 250 whp track car?
If you'll be abusing the motor, some basic rods and pistons can't hurt. Just remember, reliability is all in the build quality at that point - **** up tolerances, and your freshly rebuilt motor will grenade with a quickness. Also remember that you can't use aftermarket rods on stock pistons - upgrade one, you have to upgrade the other.
For stock cam, you don't need to upgrade your valve springs and retainers, but while the motor is apart, you should go ahead and replace your valve stem seals.
For stock cam, you don't need to upgrade your valve springs and retainers, but while the motor is apart, you should go ahead and replace your valve stem seals.
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Re: Forged pistons for 250 whp track car?
If you'll be abusing the motor, some basic rods and pistons can't hurt. Just remember, reliability is all in the build quality at that point - **** up tolerances, and your freshly rebuilt motor will grenade with a quickness. Also remember that you can't use aftermarket rods on stock pistons - upgrade one, you have to upgrade the other.
For stock cam, you don't need to upgrade your valve springs and retainers, but while the motor is apart, you should go ahead and replace your valve stem seals.
For stock cam, you don't need to upgrade your valve springs and retainers, but while the motor is apart, you should go ahead and replace your valve stem seals.
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Re: Forged pistons for 250 whp track car?
Spend a little now, or spend a lot later. If the engine blows because the rods couldn't handle it, they'll probably take the block with them. You'd feel pretty foolish if you could have avoided spending $150 plus labor time because you didn't want to spend the money now.
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Re: Forged pistons for 250 whp track car?
Spend a little now, or spend a lot later. If the engine blows because the rods couldn't handle it, they'll probably take the block with them. You'd feel pretty foolish if you could have avoided spending $150 plus labor time because you didn't want to spend the money now.
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Re: Forged pistons for 250 whp track car?
It sounded like Shodan had recommended that since that was the turbo noted for quick spooling upto the 350 whp range on a B18C and the GTX2863r for a B16
#10
Thshodans mostly never wrong. Iirc the spool times between the gtx2867r vs the gtx2867r are negligible so getting the slightly larger of the two would give you a little more play room with power
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Re: Forged pistons for 250 whp track car?
Especially in regards to circuit/track racing...that's kind of his thing. I would take his suggestions and run with it. I've purchased turbos from him based on his advice and would highly recommend him to anyone
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Re: Forged pistons for 250 whp track car?
Yeah I trust Shodans advice. When he replied, it wasn't a few word reply. He explained why (at that time I was debating disco potatoe and 57 trim turbo) the Gtx2867r was better overall.
What compression ratio pistons should I get? I was thinking 9.1:1 or should I get forged stock compression? Suggestions?
What compression ratio pistons should I get? I was thinking 9.1:1 or should I get forged stock compression? Suggestions?
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Re: Forged pistons for 250 whp track car?
91 octane. If I do stock or 10.1 compression I am going to have to use flat top pistons correct? I researched the different types (dish, flat, and domed) and flat tops seem to be what I'll need.
Last edited by Xperience; 07-14-2014 at 08:15 AM.
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Re: Forged pistons for 250 whp track car?
I know that but does it matter between dished, flat, and domed pistons as long as I achieve the compression I am looking for? Flat tops have the compression I am looking for. I just wanted to make sure that flat tops will work without any hassle. Anyway I think I figured it all out.
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Re: Forged pistons for 250 whp track car?
It doesn't really matter about compressor size with the gt(x)28xx turbos. on your typical b vtec motor the turbine wheel size will limit mass flow to around 420-430hp, this was with a 56trim 2871r...
you have to remember the gtx series still uses the same gt turbine wheels, if you can make the system more efficient with a larger turbine housing and other tricks you can squeeze a bit more out of it but ultimately the turbine wheel size dictates how much exhaust can physically leave the motor at a given rate.
you have to remember the gtx series still uses the same gt turbine wheels, if you can make the system more efficient with a larger turbine housing and other tricks you can squeeze a bit more out of it but ultimately the turbine wheel size dictates how much exhaust can physically leave the motor at a given rate.
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Re: Forged pistons for 250 whp track car?
OK thanks for all the info guys. Much appreciated. I have another question but don't want to start a new thread. I bought a used Tial 38mm wastegate last night. I need to change springs for it but I am not sure how much psi its going to take to reach 250-300 whp with a gtx2867r. Any help with determining spring size is appreciated. And I read off an evo forum that you (for example here) if you plan to daily at 20 lbs then get an 18-20lb spring. Is that the right way to determine spring size?
I plan on getting manual boost controller to get me started so I won't be messing with boost settings at all. Once I get tuned, I'll leave it alone as hard as it may be
I plan on getting manual boost controller to get me started so I won't be messing with boost settings at all. Once I get tuned, I'll leave it alone as hard as it may be
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Re: Forged pistons for 250 whp track car?
All questions I am still looking into. I wasn't sure if a ebc or mbc was necessary. If I don't need one at all, I will save my money until I can get a good electronic one. Then in that case, I just need to figure out the proper spring for my wastegate.
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Re: Forged pistons for 250 whp track car?
Boost pressure doesn't matter much, power level does. run whatever pressure it takes to make the power you want.
power vs psi varies wildly depending upon setup, fuel, and tuner so you won't have much of an idea pressure wise until it's time to tune.
power vs psi varies wildly depending upon setup, fuel, and tuner so you won't have much of an idea pressure wise until it's time to tune.
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Re: Forged pistons for 250 whp track car?
So just use whatever spring is in my wastegate when it arrives and change it after the tune when I know how much psi was used for my goal? Sorry but I am 100% new to turbo.
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Re: Forged pistons for 250 whp track car?
Well, a rough ballpark starting point for the power you want is 10-15psi... lots of factors play into it.
you'll need some sort of boost controller (electronic is better imo) in order to raise pressure.
Do you know what spring is in the TiAL? take the top off and take a pic, It's either a small or large spring and it should have colored paint down one side, that tells you the psi of the spring. report back with a photo and we can narrow it down.
you'll need some sort of boost controller (electronic is better imo) in order to raise pressure.
Do you know what spring is in the TiAL? take the top off and take a pic, It's either a small or large spring and it should have colored paint down one side, that tells you the psi of the spring. report back with a photo and we can narrow it down.