I have a b18c1 benson sleeves bored to 84mm, bc stage2 turbo cams, and supertech valve train. It dynoed 458hp and 338tq with a sc61jb turbo at 19lbs on 93pump tuned on neptune. My question is I'm going to 91 pump and was thinking of changing the turbo up to a possible 6262 with .63ar. I want to keep good streetability, Can anybody chime in and let me know if it's not a good idea or any input? Thanks and I'm new to this forum

 

You'll make about the same as your SC61, slightly more peak power with a 6262. "Streetable" is in the eye of the driver, as I would never consider something that large as usable in that lower efficienxy range, especially at only 91 octane. You'll easily have people with smaller turbos out-accelerate you in a street environment, but again, that's your call. But your fuel is limiting you.

 

Ok so say I keep my 61. I have no choice but run 91 anymore. How big of a hit approximatly will i take dropping to 91 vs 93?

 

And I am boost by gear so what would you think to be a better charger for the street?

 

 

Yeah I'm not too thrilled about it but 91 is the best I can get in Montana.

 

So back to my question, does anyone have any insight as to what charger, preferably precision and detuning to 91 octane would be my best option?

 

Get a smaller turbocharger, (where although you make less peak power you gain MUCH more usable torque in a nicer powerband...perfect for the street) or increase octane and knock-resistance by running a meth-water kit ( you can even make your own methanol) or purchasing higher knock resistant fuel. Or both...

Outside of that, no.. you can do nothing more

 

something in the 41lbs/min -53lbs/min using both oil and water cooling for longevity . (Please note, many journal bearing turbos have option water ports for better cooling.. It doesn't have to be a ball-bearing unit to run water)

As a measure of comparison, your current Turbocharger ( depending upon which SC61 you have) is about 60lbs/min - 62lbs/min. (Similar to a GT35R) Much too large for those purpose on that fuel
check out some of the dual purpose builds on the FI forum to see examples

 

I was looking into methanol injection but know nothing about it. As for my build beside stated above, it has a stock crank, eagle rods, weisco pistons, 10:1 cr, bwr ramhorn mani, Id 1000cc injectors, aem fuel rail, fpr, and a walbro 450. And again on neptune tuning. What sort of water methanol kit should I look into? As I was thinking it wouldnt work for my build. Thanks

 

why would you think that would never work? Yeah. Head to AEM (Advanced Engine Mangement) and check out the videos. You can also find out about it on YouTube...

Just check it out first. Be your own research advocate, as no one knows your needs and budget better than you

There's also Snow Performance, Aquamist, and Devil's Own. These are universal kits

 

And as for the turbo, thanks for the info. I will look into something smaller, so I may have the sc61as a paperweight. It's just hard to believe that a smaller turbo would outperform the setup now. If it had wings, she'd fly. And I understand spinning is loosing, but alot is tuned out and I feather as needed. I am going to dive deeper into the water/methanol kits since the car is setup/tuned on 93 and now I live in a 91 state. And now the car just sits till I get this sorted out.

 

And I just assumed water/methanol kits were for monster power as I never really looked into them. But understanding my 91 predicament it makes alot more sence now. I wasnt looking at it from both angles. I seen them as a power adder and not an engine saver of sorts

 

Feathering is "fighting" the cat and not driving. You're not the first person to believe that a smaller turbo can outperform a larger one on a street application. Many younger enthusiasts look at Peak power as though that it represents the horsepower that's going to be throughout the entire RPM band, when that is simply not the case at all. You can have all of the peak power on the world that you want, but, if that power is only going to be in the last 1000 rpms of your RPM band, at over 40% throttle because you're fighting the car, then you're really not racing at all. What you're experiencing is the light switch effect in which nothing comes of the car until the very last 2,000 RPMs for a small Split Second of time.

 

Damn that makes a ton of sence. And I looked into the water/meth kits and you are right, it's my best option hands down. So I will do a little more research and get one. And so goes my other question. With what you've gathered from all my info so far, can you point me in the right direction for a charger? I'm jb now but would like to switch to bb for the quicker spool and longevity. Precision is choice but I wont shy away from others. Maybe a gt30? Or any other option to search would be helpful

 

you'll find many here stay away from Precision and have done so for a number of years. Unless you're strictly drag racing, you'll find most stay with Garrett, (and their aftermarket affliates), Borg-Warner EFR, and Turbonetics.

that's an entirely different discussion in which you have to have a budget (in real dollars) and your mechanical inclination. Be ready to read, and absorb information