Unrelated turbo question

This question is unrelated to nissan but I'll throw it out there anyways. I'me planning on turbocharging my 85 F-150 and I was wondering what size turbo I'me going to need to supply a 300ci inline six with about 6-10 psi. I know the Buick Grand National had a turbocharged 4.9 but I don't what turbo they used. If anybody knows which turbo buick used for this or what size would work it would be greatly appreciated. Thanks in advance. Oh yeah 300ci works out to a 4.9 litre.

This shouldn't have been in General, and I'm putting in Coffee Shop.

Now, with that said, what is the compression of this engine? 6-10 sounds a little steep for an NA engine of any size.

Two RB25DET Turbos would work well. One for each side. Run about 4-5psi MAX with a nice cooler!

Dont use old school turbos just because they are "T3" or "T4". They just arent up to scratch nemore.

In auz, a workshop used to RB20DET turbos on a 4L Ford inline 6 and were capable of flowing 500hp. Spooled 13-15psi by about 3500rpm.

My 2c

If you think a T3 isn't "up to scratch" then you are seriously uninformed about the hundreds of cars running T3's with serious power and excellent spool, given it's paired with the right exhaust side.

Before I went T28 on my S12, I would use a T3. More flow than a T2/T25/T28 exhaust housing allows for more topend. I had to be convinced of this a week or two ago. Now I am after doing more homework. A T3 can outflow a T28.

Its got about 8 to 1 compression. Also its got a Clifford Performance intake manifold and exhaust header match set, its been port matched, polished and relieved. I run dual 2 1/2 inch pipe through a pair of turbo mufflers. Its been balanced, blueprinted, had the flywheel shaved and now redlines at about 7000. Msd blaster coil and msd ignition, cold air intake, 270 duration Comp cam, new valve springs and valve grind, new crank bearings and new piston rings. Its pretty beefy already so its ready for turbocharging (I think).

Salps12 said old school T3, which is true the older ones do tend to be quite sucky, but they do work. My mate has a S12 Silvia/Gazelle turbo on his 3TGTE in a TA22, seems to work fine. But before you start going on about T3 there would literally be hundreds of different T3s floating around, you can't catagorise a turbo by saying T3, T4 unless you are only talking about flange size really. The T28 is usually a combination of T3 or T04 parts as far as i've seen. I'm not much of a turbo sizing expert tho.
The 4L salps12 talked about there was done on a really tight budget, a pari of RB20 turbos aren't the most sought after things so you could do it on the cheap :), also your compression ratio is already low good for mild boost me thinks.

i think salps12 is not having a go at the T3/T4 themeselves but rather just saying that the older models of these aint as good as the new...correct me if im wrong but isn't there hundreds of different T3s and T4s all of which have different spool up, max flow etc some of which good for the application some bad...
not a turbo buff so flame away :)

haha i should have refreshed my browser before posting neb had it covered:tongue:

I checked out the wrecking yard and they say they have a turbo off a grand national for 800 bucks (a little steep) and they say its a Holset turbo. I thought Holset only made turbo's for big diesels but unless this one was put on as an upgrade I guess they made small ones too. I also priced out an Eaton centrifugal supercharger and they are about 1500 used (ouch) so I think it will be a turbo. I was hoping for a single turbo to save on cost (I'me broke most of the time) and to keep it simple. Btw, I found out that the Ford inline sixes have SEVEN main crank bearings, one between each connecting rod!! Can you say bulletproof, it seems these thing are just about the toughest engines ever built.

I know the Buick Grand National had a turbocharged 4.9 but I don't what turbo they used

GN's are 3.8 V6's, the older 2nd Gen Turbo Trans Ams were 301 ci., but had a crappy draw through carb'd setup.

Go to the junkyard and find a T-bird turbo coupe, or other turbo'd 2.3 Ford motor (SVO, Merkur XR4Ti, etc.). You could run twins if you used the smaller .42/.48 A/R off of the automatic tranny turbo coupes. The manual trannys had the larger .63 A/R, which might be alright in a single setup, but I think you'd be better off with two of the smaller ones.

Go ahead and run an intercooler too, but I would still keep the boost down below 10 psi...

This is an inline engine right? T3 would probley be best. Don't buy a junkyard turbo for 800 dollars. You could get a brand new turbo for that much.

Nope the engine is an inline six. I am thinking if I don't go the twin turbo route for my 200sx I will use the two t2's for low boost (4-6 psi) because the more I think about it I think a low boost setting will do wonders anyways. I'me also looking at a standalone fuel injection system by Clifford Performance to add to the mix. They say a NA inline six can push 300hp with this kit and Clifford intake and exhaust (which I already have).