ChrisYuki

Hello everyone, I decided to make an account here to ask some questions i have with a future build of mine. I'll start off by explaining my current build:

I have a LS VTEC over bored to 34.5MM. It's sleeved, has forged wiseco 10.5:1 compression pistons, forged eagle rods, and a stock GSR head. Thats the basics of it at least...

So, I really would like to boost this motor in the future since its sleeved and has forged internals. My problem is, I kind of set the compression too high with the pistons/head (it was originally going to be a very simple all motor build lol). Is it possible to boost this setup on pump gas (91)?

I would like to safely make an additional 100whp which would put me around 310whp. Is this possible without detonation? Or would the turbo just increase the compression far too much?



I know nitrous makes more sense for my build...but I just have always wanted a turbo car lol.

TheShodan

iTrader: (14)

Hello, and welcome to H-T. You're pretty much speaking to one of the nicer folks on this forum. Please remember this is simply a forum , and not a personal attack towards anyone that comes in fresh and new wanting to understand turbocharging and other forums of forced induction.

All we ask is that you have a willingness to learn, and open mind, and don't take some comments personal. Once you've gotten adjusted to that , you can fire away with questions, as long as they are thought out, researched (we get a LOT of redundant questions here), and asked in a mature manner. You do that, and everything will be just gravy .

Now that the pleasantries are out of the way, I'll get to the point... You're stuck with a lot of old presumptions that tend to die hard in the world of forced induction. Your compression is PERFECT for turbocharging and there is no need to believe that nitrous is a better option based upon your compression. That's utter nonsense. As NotARacist usually points out, with the right tools and technology in the right hands (I can't stress that enough), 10.5:1 compression is just fine, and there is no need to go any lower than what you have, yes, even for 91 octane fuel. 310whp is a cake walk.

I hope that at least alleviates some concerns.. And again, welcome..

ChrisYuki

Hey, thanks for the warm welcome. There is a TON i do not know about forced induction. Im definitely learning. You can only google so much though lol...

I would say my compression is more towards 11:1 because of the gsr head (maybe 10.7:1?). I doubt it's thaaaat much of a difference though. So in theory I could handle more boost? Around what WHP could i safely reach?

My bottom end is rated for 600whp+, so im not worried about that....just worried about other things failing.

NotARaCist

iTrader: (1)

If your bottom end is rated for 600WHP, then there you go. That's what WHP you can safely make. With that number, though, I'm guessing you aren't using completely stock sleeves?

11:1 is NOTHING for a good tuner. You can easily boost on that, quite safely, as long as your tuner is worth a ****.

ChrisYuki

Yeah, my block is sleeved and I have forged internals. So lets say i boost to 400whp, what would be a weak point? head gasket?


EDIT: Sorry im super paranoid lol. I have so much into this build, its not even funny, so I want to keep it as safe as possible. People have definitely warped my mind with "high compression = no boost", so its hard to adjust. If there is anything i should beef up before boosting, let me know though.

Ideal setup would be to have a way to toggle between two "modes". A street and track mode. I dont want a lot of boost on the streets (maybe 275whp), but i would love to have full power on the track.

NotARaCist

iTrader: (1)

400? Not much. Possibly nothing, depending on what else you have in the motor. If your fuel system can handle it, and your clutch can handle the torque, there's nothing stopping you from slapping a larger Garrett 28 series, or smaller 30 series on there, and having fun with 400 WHP, and not having to refill a bottle. A GSR head can flow enough for 400 by itself, but some mild cams (I like Crower 403's) would definitely liven it up.

Your build is similar to mine, and your power goals are the same as mine. A GTX2871R and 403's are great for it.

wunfstgsr

These days its no problem as long as the parts are right and the tuner knows what there doing.

A set of head studs and good axles are always good!

I think with the AEM EMS you can save multiple tunes but not sure. Look into boost by gear as well.

NotARaCist

iTrader: (1)

Who was it that was running on like, 14:1 compression until their wrist pins bent?

And yes, quality head studs are a must. Can't go wrong with ARP. You said built for 600, so I assumed head studs were included in that, but just in case...

wunfstgsr

Was it CaliforniaDad?

Yea last thing you want is the head lifting but im sure some ARP studs made it in there being its a LS-vtec hybrid.

ChrisYuki

Yep, definitely went with arp head studs :D. That GTX2871R is out of my price range atm hahah. Im far too deep into my engine for that lol. I definitely want to pick a decent turbo though. Kind of want to avoid ebay level, but do not want to break the bank either.

I was definitely considering boost by gear tbh. I just do not have any experience with that. It progressively gets more boost? Would it not be better to just a solid boost figure?

NotARaCist

iTrader: (1)

Here's a car joke for ya. What do an 800 horsepower Supra and a 2000 horsepower Supra have in common?

An 8 second quarter mile.

It's all about traction. Long story short, shorter gears deliver too much torque, wheels spin, and power turns into smoke. Boost by gear lets you dial in different boost levels for different gears to prevent wheel spin. If the 2871 is beyond your price range, maybe look at the STC Hunter? If $840 is out of your price range, then a quality T3/T04E (57 or 60 trim, smaller won't get you there without blowing hot air) can be found for $650-$700, but it's older tech.

Don't forget supporting mods, either. A quality intercooler, and a good BOV and WG can add up quickly.

VegaS10

The little parts (well, everything) add up quickly.

You may want to look into a Go-autoworks for a simple solution and just buy everything at once.

OneBadTurboCRV

It was Muckman and he was running 13.5:1 IIRC. I was (and will be shortly) running 12.5:1 myself. You just can't beat the response out of boost. Until you have driven a higher compression turbo build, you just don't know what you are missing. The naysayers are just full of it and jealous they don't have the ***** to do it LOL!

Of course though, you won't be doing this on pump gasoline alone though...

OP - With your lower power goals you should be fine, but there is always water/meth injection. 91 octane does suck though and supplements may be needed if you want to crank it up at the track. You could always swap fuel for track days. It really depends on how often you want it set to "kill" LOL!

Flr Power

The fuel octane and target horsepower dictates what max CR you can run. I can say 11CR would work (on low boost) for 300whp on 91 octane. In the end, a lower CR would work best and produce more HP with 91 oct and 20+psi.

m4xwellmurd3r

No it won't. Because if only compression ratio was the difference, then the cylinder pressures between the low comp high boost and high boost and low comp would be similar

Octane only limits power. A low comp/high boost setup will have nearly the same power/octane limit as a high comp/low boost setup.

At lower power levels a high comp boosted setup is even more desirable. High comp means a higher base power point, more power out of boost, and more power per psi. I think higher comp also results in better turbo response times, making an even more potent setup.

A low comp setup is a slug out of boost, and is more dependant on the turbo for its power. Requiring a higher boost psi also means it (I think) will take longer to reach the target boost level, further hindering it.

Two identical setups, with the only difference being compression, tuned to near identical power output, in a race, the high comp setup will win.

Geis

lol
'b16 tranny is the last thing you should worry about as far as traction problems go.'
'You should get a b16 for your turbo build, shortest gearing possible is way better for turbo'
As far as turbos go, you can easily pick up a used on in good condition for better prices than that. Was eyeing a 50 trim myself for 300$.

NotARaCist

iTrader: (1)

Geis, are you attempting to take things out of context to...well, I can't even tell what your goals are. Care to be a little more clear? I could take a guess, but I don't want to make you feel stupid, since you seem so sensitive about it.

...wat? No. Stop that. Go educate yourself before you continue propagating the "low CR for boost" bullshit. It was true back in the 90's, when we had to work with what we had access to. Today, we have free tuning options that are better than the **** you had to pay hundreds for back then.

Higher CR means more power out of boost. More power out of boost means you can blast harder after shifts and coming out of corners, which means faster lap times. Get your CR as high as you can, within the detonation threshold of the gas you're using, and go to town. Do I really need to go on my tirade about why low CR is wrong?

Geis

It's kinda ironic how you say that I'm being sensitive about it when I was making light of what you've said before as a joke lmao.
In all serious you do go around saying that short gearing is the best all time and that it shouldn't be a factor as to why you can't get traction - yeah maybe if you are keeping the power in the 300s or lower but it sure doesn't help in the first two gears.
Also the thing about the supras is kinda unrelated seeing how the 2000hp supras aren't build for the 1/4

NotARaCist

iTrader: (1)

See? Out of context.

Shorter is better, when looking within OEM transmissions. The context conveniently left out. Yes, a complete transmission is the last thing you should be looking at, because there are so many other things that will help traction. Better tires, a proper alignment, other suspension components, boost by gear, and even a proper differential should all be done before saying "my gears are too short".

And yes, the Supra thing was a joke. Like I said.

Flr Power

Did you ever tune two identical set up but with different CR?

NotARaCist

iTrader: (1)

Have you? Given your previous ignorant statement, I'm gonna guess the answer is no. We're closing in on the end of 2015. Please, come join us in the 21st century. It's nice here! We have better technology in our engines, better technology in the assembly of our engines, and better technology running our engines!

Higher compression, within the capabilities of the fuel, is better.

Flr Power

I am actually a low volume multi platform tuner. I also have been tuning for a long time. I guess you could call me an ignorent tuner haha.
But that's okay, I have met many people with your know it all attitude.

AZ_CIVIC

iTrader: (1)

I say build what you want.. I run 9:1 compression pistons and made 801whp at 31PSI out of a 62mm turbo. I could probably turn it up and make 850whp out of my 62mm. As far as laggy, hell no...

Even if I ran 11:1 compression and gained 20whp still doesn't mean too much especially in a FWD Honda. I've gone faster than guys with 100 more WHP just for the simple fact I have a better suspension setup.

I say higher compression, quicker spool and a smaller turbo is best suited for road racing guys or someone who is looking for a DD street car. So if that is where you are going by all means do it. For Drag racing, big power and quick quarter mile times I personally don't think it makes a big difference at all.

NotARaCist

iTrader: (1)

Not only did you conveniently sidestep answering your own question, but an appeal to (false) authority is no better than Argumentum ad hominem. Try again, or go hook up with the Encino man and comiserate about how great things "today" "are". Since I know you won't, though, I'll just go ahead and say this again.

Period. End of.

Muckman

iTrader: (2)

I should ban you.