Which will make more power?

[V8KLR]

I have a 91 Laser RS n/t with a turbo (14B). With 9:1 CR i'm running 10PSI on 93 octane. Could I make more power with the turbo pistons and around 15PSI or does the higher compression of the n/t pistons make up the difference in power?

 

[cheap90gsx]

boost vs compression ratio depends on setup. for you, the NT pistons are known to fail due to the difference in ring lands.

 

[delta448]

It all depends on the tune and the supporting mods.

1G N/T injectors are only 240cc, there's no knock sensor on a N/T, and I don't see any turbo fuel/ecu swap related upgrades listed in your profile. Have you at least been logging the current setup to make sure you're not destroying the engine?

 

[lockout]

with the lower compression pistons you in the end can make more power without anything breaking.my buddy did that to his 90 talon but only ran 5 psi when he went up to ten a rod gave

 

[Unwythe]

Take that turbo off right now, if you do not have any supporting mods. The rings on the non-turbo pistons fail ridiculously easy on the 1G non-turbos. With stock pistons, you'll make more power with the turbo pistons, for the simple fact that you can turn the boost up higher without worrying about the rings shooting out the exhaust.


In the end though, higher compression pistons will 1) Spool that bigger turbo faster(if you get a bigger turbo) 2) provide more low-end torque due to the higher compression 3) Make a bit more power than the lower compression does. But this is on tuned and built motors designed for racing. Grab yourself some 2nd Gen Turbo pistons(they are 8.5:1 compared to our pathetic 7.8:1), get them mated to the 1gA big rods, get all your fuel mods/knock sensor/wiring done, turn the boost up to around 15(if you go with stock turbo fuel pump/injectors/etc) and you'll be golden.

 

[V8KLR]

Sorry, I just now updated my profile mods. I have logged a few runs on the car and I have 0 knock on 93 octane with 10PSI. Timing looks good as well, around 17deg at WOT. I know the ring lands are fragile on the N/T's but as long as I have no knock I dont see any problem, I just wanted to know if I could expect more power using the turbo pistons and higher boost.

 

[kris_stewart10]

how are you logging knock when you dont have a knock sensor???

 

[V8KLR]

how are you logging knock when you dont have a knock sensor???

If you would have looked at my mods you will see that I DO HAVE A KNOCK SENSOR. Goo god, all I want is a straight answer.

 

[kris_stewart10]

sorry bro i was just asking but the turbo pistons will generate more power because the rings on the NT pistons are HORRIBLE but

take it from me i have went the way you went and turboed a NT well lets just say the turbo model pistons are better, stronger and produce alot more power by far

but yes go with turbo pistons if anything go with aftermarket maybe some JE

 

[V8KLR]

sorry bro i was just asking but the turbo pistons will generate more power because the rings on the NT pistons are HORRIBLE but

take it from me i have went the way you went and turboed a NT well lets just say the turbo model pistons are better, stronger and produce alot more power by far

but yes go with turbo pistons if anything go with aftermarket maybe some JE

Thanks, turbo pistons it is!

 

[viperlp01]

Boost is better.... But in your case it takes less boost to make the same power. You can only run so much on them high compression pistons. You can run more boost on lower which will eventually pass the power the higher comps make unless the motor was seriously built.

 

[kris_stewart10]

turbo pistons all the way i think you will do good buddy

 

[delta448]

Glad to see the necessities are indeed taken care of, I had a feeling they were.

Now about the pistons, I believe that you'll be much better off with turbo pistons. The higher compression is great, but the N/T pistons are obviously weaker by design as mentioned. I'll assume you'll want to increase power even further in the future so going with lower compression stronger pistons now would actually help in your case, both now and later on down the road.

My reason being that the 1G turbo ECU uses a fairly aggressive timing curve to begin with to optimize the low 7.8:1 stock CR; and adding an SAFC coupled with larger than 450cc injectors in the future will only compound that issue. If you were to continue using the higher compression pistons you'd probably run into knock quickly with pump gas and the SAFC compensationg for anything larger than say, (speculating) 550cc injectors.

You'd then have to add water/meth injection or switch to alcohol fuels to combat the knock at a modest boost level, likely resulting in lower peak power, more headaches, and much more equipment investment, only to realize you still need stronger pistons.

 

[V8KLR]

I thought about adding water injection so I could turn up the boost a little more but I think i'll just go ahead and get the turbo pistons. How much power will the stockers hold?

 

[viperlp01]

2g pistons on 1g rods will hold around 30pounds pretty easily if the block is fresh. I know 99gst racer made 400 hp on stock internals at like 2.2 bar.

 

[tkelly27]

350-400 reiably, 500ish has been done, but your tune better be spot on, and I've heard rumors of 600, but I have no idea if that is true or not.

While you are changing pistons you should go with big turbo rods. Also, you have the option to go with 2g pistons if you like the higher compression idea. Then you can have safe reliable high boost and compression at the same time.

With tunerpro, DSMap, or ECMlink you can alter your timing map to better handle the 2g pistons too.