Daz

iTrader: (18)

I'm building a 4.8 turbo for my datsun and I just need to know if 317's will work ok for it, being that the compression will be low(not sure how low). The bottom end will be stock but with ARP rod/mains, LS6 cam/oil pump, LS6 intake manifold. I plan on a .70mm+ turbo, 60lb+ injectors, dual walbro's . My goal is 550whp in a 2500lb car.

NemeSS

iTrader: (127)

They will work but scr will be in The 8s. For that Hp level makes more sense IMO to keep stock heads, and keep the 4.8s 9.4:1 scr. Will support 10+psig on pump gas assuming your fuel and cooling system can handle it, with fmic

Daz

iTrader: (18)

What if I shave .20-30 off ?

Nevermind ! I don't think I'll run more the 12-15psi !

NemeSS

iTrader: (127)

I don't like to cut off more than .005 on any oe ls head that's going to see psig

Daz

iTrader: (18)

My dad has a set of 241's that I might use ! My uncles can port them for me too !

Chicago TDP

iTrader: (3)

Put the 241's on.
No porting needed.

I have a 4.8L with 317's, too low of compression, has a good amount of lag.

Daz

iTrader: (18)

Thanks ! My uncles are pretty awesome with porting and they'll do do it for free I just have to buy the burr's . Are you using 1 walbro or 2 ? I'll be running 60lbs injectors and maybe a truck intak or ls1/6.

Chicago TDP

iTrader: (3)

If you put in 1 Racetronixs pump, you should be fine with Premium gas and 60's.
If you want to go beyond 600 HP, you will want bigger injectors, especially if you want to run E85. The 70mm can get you pretty far in HP.

Daz

iTrader: (18)

No, No ! That will be plenty for me for a while ! The car weighs around 2600lb stock. and about 2830lb with me in it(stock). I've removed some stuff on it so I'm guessing around 2600lb with me in it at around 500+whp will be crazy fast for me plus it'll be able to corner too. E85 would be nice if I didn't have to drive so far to get it ! Thanks for the info !

Daz

iTrader: (18)

I see that the Racetronix FP will support up to 600hp for there universal. I can live with that.

Wicked69

Would the compression still be too low with a set of 317's on a 5.3? I was thinking I would be around 9 for compression. I am debating if I should just leave the stock 862's on there. I could mill the 317's a little. Is it just too low on a 4.8?

Daz

iTrader: (18)

I was told that its around 8.2:1. I want around 9.0 to 9.4 .

Daz

iTrader: (18)

According to the compression calculator here:http://www.gtsparkplugs.com/CompRatioCalc.html it will put you at 9.17 which is good in my book.