60pontiac

Hi there guys, I have a question about turbo-ing a lq4??? what parts indefinanatly should I change out, I am going to start a tear down for a rebuilt starting next month so this would be a good time to get necessary items as needed. ill start off with my goal for power: im not looking for the fastest street car in my area. this is going to be a daily driver that I would like some power if I feel the need or if a civic or a mustang needs to be disciplined on the street lol. I would like to see about 500-550 hp/tq with a turbo. I really never been a turbo person Ive always been a supercharger type. with the way of turbo technology has come these days it seems more cost effective and more reliable these days, plus it looks like they put out more power than just a supercharger now days with some research I been doing. the car im putting it in is a 1960 Pontiac Bonneville 2 door, I sold the 455 that was in it so I can start the build. room under the hood is nooooo problem at all I have tones of room. put it to you this way I have more room under the hood than my 60 Cadillac I had so tubing would not be an issue. so far I know I would be using stock crank, 317 heads, and I will be getting a ls6 int. what cam/springs injectors/ fuel rails would I need? and I see people using truck ex-manifolds, whay is that? any help would be grateful.

66Chevellelq4

welcome to the wonderful world of ls power! Im going the sae route as you, turbo chargin an lq4 and dropping it into my chevelle. I stuck with the stock truck intake as well as the stock 317 heads, the only things i changed were things i dont really want to be messing with once the engine is in the car. I put in a new cam, high lift springs, new lifters (iv heard horror stories of these lifters failing, i guess its pretty common) and then i also got some new head gaskets and arp head bolts. If you want to save some money i have heard the chinese head studs work great, tons of guys use them and make great power. For my power goals im looking to be in the same range as you, about 500 to 550 at the wheels. I will be using the stock truck manifolds flipped forwards, there are incredibly strong and the work well for hotside piping. As far as turbo choices go, have you narrowed it down to anything yet? I have gone back and forth on either a borg warner s475, or getting the 80mm gt45 from vs racing. Ill have to make a choice one day and just go with it! I cant wait to see you get a build going and watch the progress. Good luck!

60pontiac

thanks for the info, im kinda interested in something that spools up quick I don't think I would be hardly ever gonna rev it past 5000 rpm's. looks like everyone like borg warner but im still gonna look around and look at reviews. what would you suggest? remember room is not an issue by all means. twin turbos would be cool but more expensive and harder to tune n all. the truck int would be ok to go with? what size pipping are people using? thanks for posting any ifo helps btw my 455 was a tq monster but getting 5-7 miles gal. was not cutting it lol, that's why im doing this conversion.

66Chevellelq4

I can GUARANTEE you will rev that sucker way past 5 grand! These engines can take it, no problem. I plan on backing off around 6,500 ish haha. for turbo choice i have sent emails back and forth with the guys at huron speed, and forced inductions, just look them up on google and shoot them an email, they know a heck of a lot more than me about this stuff. They can spec you something perfect for your setup. Yeah i had a super torquey 396 in my chevelle, and i got about 5-7 as well. Its not too fun on a college budget. The engine is still sitting in the car, but next break i get from school im gonna fly stuff home and get wrenching! I lurked on here for a while and couldnt believe the numbers and streetablilty these guys were getting, so thats why i decided to make the switch. I have everything pretty much ready to go, i just need to find time to do it. BTW twins would be awesome on your cadi, dont rule it out just yet, it can be done fairly cheaply, and i love the symmetry on setups like that. Good luck!

redss82

If you want 500 too 550 hp throw some pac 1218, some 60 lbs or 80 lbs injectors which ever you can get cheaper at the time, throw a 70mm to 76mm turbo, some 2 inch hotside should hit pretty fast and give you the power you want pretty easy

yenkomike

iTrader: (2)

the power you guys are looking for can be made with a stock lq4 with a valve spring upgrade. it wont take much to get you there. im sure that new on3 78/75 turbo can get you there as well . if you are going to stick to your goals there is no reason to go with a ton of aftermarket parts just a good engine and a little boost and you will be happy.

forcd ind

iTrader: (7)

your going to be fighting weight, full size Pontiacs were orig pretty heavy, so torq is needed to move it on the street
a smaller cam, turbo setup to spool early, maybe give up some on the higher RPM's
sizing turbo's seems to be all over the place, I wanted quick spooling, some suggestions here, but when I ordered one they offered a larger wheel-sure hope it wasn't a mistake, I would hate to end up with having to redo the turbo
I guess listen to the guys that are actually using the parts, remember you have a heavy car

Sarg

iTrader: (6)

A heavy car yes, but also a good torquey motor. I would do twin Borg s256 turbos with the t4 housing. They can be had pretty cheap and will flow plenty if air. The single option would be a 87 or 92mm turbine s475 for a good single. Either way will be plenty powerful for your goals and spool up quickly. Just use appropriately sized hot side piping with a good sized downpipe(s).

60pontiac

man you guys rock this is vital info and most appreciated guys its helping me getting closer to the decision of the rout I wanna go. the weight of the car surprisingly is not that bad, it weighs 3946 lbs. not bad for a 19' car. im seeing that the 98-02 cameros and f-birds are in about 3600 and some change??? so 2'' pipping is what size I should be going for as far as the turbo goes? remember im new with turbos. what should I be looking at as far as valve springs, cam, rods? would roller rockers be worth going with too? Now here's a bitch part of this......fuel pump......? should I go external due to my gas tank being very unique, its a 1 year tank the 59 and 61 tanks are way different in the 60 model. its 26 gal. and its not very deep it really wide and long. I wanna say the tank is only 7'' tall. thanks again for all your help guys!!!

Sarg

iTrader: (6)

If you go twins I would do 2" piping merging to the collector of the turbo which will be around 2.5" for a t4 turbo. If you are going a single T6 turbo like the S475 then 2" or 2.25" from each side will go right into a divided flange. This is all leading TO the turbo. After the turbo is larger....3" for the T4 twins and 4"+ for the single T6 turbo and then if you want split that out into twin 3" tubes.

You would need two wastegates either which way you go. I would try to get 44mm wastegates as you will be running fairly low boost on a somewhat big motor to achieve your goals.

I went with dual spring valve springs, upgraded the push rods and went with a "trunion" upgrade kit from comp. I went with stock rods, crank and pistons. For the camshaft, you would honestly probably be fine with your goals with a stock cam. But if you wanted something that will have room for improvement if you decide to turn things up, I would contact LilJohn for a custom grind. He can spec it any way you want it.

Lastly for the gas tank, I think I would go external and just do a sump. If the tank is still good, you could get a sump welded on to the tank on the bottom and then go with a good external pump. The new Holley dual pump series have shown excellent results lately and are reportedly very quiet.

60pontiac

Thanks Sarg, I had to read it a couple of times lol but im getting a better hang of this turbo thing. what is t4-t6? is that have to do with the size of the spool or flange? im seeing that a lot with the turbo talk, in your opinion how much would a twin setup run? remember im not making this car a street racer, just something to turn heads every now and again and the occasional get up and go.

Sarg

iTrader: (6)

A lot of it depends. I shot you a pm with my number.