Small Turbo for Torque ?

royalchoppers · #1 (**permalink**) 03-17-2008, 01:32 AM

Hello all. I usually reside at the FE section but have been reading up on this forced induction section. I have learned a lot from many of you guys and appreciate your knowledge. Where I am confused is turbo sizing. I have searched but haven't found much specific info. I have a '65 Ford F100 short box with a 352/c6 combo. The internals in the 352 are stock and it has the usual bolts ons. I am very interested in doing a low boost turbo setup. I imagine 5psi wouldn't hand grenade the stock internals. I would like this truck to be a very fun street truck that would see occasional 1/4 miles. With the redline being sub 5000 just how small would I want to go on a single turbo build. If I use a small turbo it spools quickly and I assume if it is too small the it will limit the RPM the enigne can turn. Now I am rambling. Please help this turbo FNG.

royalchoppers · #2 (**permalink**) 03-18-2008, 08:17 PM

Nobody huh?

Freightrain · #3 (**permalink**) 03-18-2008, 09:56 PM

From what my buddies know in this area, you're on the right page. Alot of the guys are running two small units, for quick boost and since two, there is the volume they need for big boost(power).

I had envisioned two turbo coupe turbo's hanging over the inner fenders of my '67 352. Hoped to see 4-5# of boost. Just enough to make it stupid fast if I felt like it. Make a pair of log style exhaust manifolds, mount the turbos directly above and plumb each into a box holding a carb. Too bad the old truck rusted to pieces long before I ever got around to fab'n up the manifolds! Talk about room.....plenty under the hood of these trucks....so plumbing should be easy. My friends all have Mustangs(new and old) and wow what a nightmare!

royalchoppers · #4 (**permalink**) 03-18-2008, 10:20 PM

My buddy Freight to the rescue. I was thinking if I could do a single it would be cheaper than a dual because of fewer BOV and Wastegates. Although I guess you could plumb both pressure pipes into a large Y before it went into the pressure bonnet and just run one BOV. Since I am not looking to make large PSI and stay around 5-6PSI would a draw through be a decent setup? Seems like it would be a lot less hassle when compared to the blow through.

Freightrain · #5 (**permalink**) 03-19-2008, 01:24 PM

Not really sure how well the draw thru stuff works? For supercharging it's great, but turbo is another story. I know blow thru turbo is real trick to get tuned. I have a buddy that has a '67 mustang, 351/turbo and it flies(been low 10's street legal). The carb is a real work of art and he's spent a few years getting it right. Granted, with minimal boost, lower power and "just a toy" that your truck would be I'm sure you could get away with less.

I've found out alot just on my blower set up. I put it together 8yrs ago and it's been "okay". Last year the bug got to me to kinda make it work better. Scrapped the 600 vac Holley's and found a pair of 660 center squirter's and WOW....geez, what a difference some fuel makes LOL! It really woke it up! Of course it's get terrible mileage(used to get 10 mpg), now only 5~ mpg........but it FLIES when you want it to. Still in the tuning stage as it's still just a street toy, but I want more..more.....more! Got a pair of slicks from race car to mount up for this year! Need to work on those 2.0 60' times! 111 mph in street trim(air cleaner/mufflers) is showing power..just need to hook it up.

Need to search and find that thread with the fellow with the red 65? with turbo. It was a super sano install.

royalchoppers · #6 (**permalink**) 03-19-2008, 02:04 PM

Your car sounds like a lot of fun Freight. That gas mileage is silly. Yeah, that red turbo '65 is cool. It looks just like my truck but mine is a SWB. I guess my question is just how small of a turbo for a single setup can I go without choking the crap out of the engine. I found a turbo calulator that tole me a t25 with a compressor AR of.82 would be a good setup for 6psi. I just can't find a t25 with that AR.

Here is that calulator. http://www.turbofast.com.au/javacalc.html

Freightrain · #7 (**permalink**) 03-19-2008, 03:37 PM

Ya, it used to go really far on 20 bucks...now it's only a few miles! LOL!! Even at cruising speed, it doesn't matter. The 660's have no power valve, so they are not meant for mileage-only go fast. And they do.

Only "good" trip to track was last fall(turkey weekend) and it was stupid crazy trying to get it moving. Two passes, first one I bogged it hard, still went 14.0 @111 mph. Second pass it got crossed up bad(left banzi style) as it blazed thru third gear and got sideways a bit too much and I had to lift to 15.0 @107 mph. This was with 5# of boost on stocker 390. Ya, it needs tires.

Man, turbo's are the thing, but not really sure who to turn to to get information and find the right part.