First off I appreciate all the help!! I have decided to go with the supercharger option. I will build a supercharger ready LQ block engine, something like 10:1 compression and in the neighborhood of 400rwhp. Then add the supercharger later.
The reason I decided to go this direction is that it will give me the change to try out a higher HP engine as well as get my car up and running more quickly. Also, I will be able to save up more for the supercharger and I can upgrade all the other components before I get the HP up to ballistic levels.
The budget that I'm looking at would be 4-5k for the engine, using a junkyard LQ. I'm sure there are many ways that I can get to the power that I am looking for, but I would like the engine to be ready for a supercharger without replacing much when the time comes. Since I am not sure if I will use a centrifugal or roots supercharger, would there be different combinations for each?


Original Text
I have just started on my project car, a 1995 Formula Firebird. I got it for cheap because the previous owner ruined the LT1 in it. So I figured that it would be the perfect candidate for an LSX swap. I have decided the best option for me would be to use an LQ block. To give an idea of what I want to do is, get a fast street car, so it needs to be reliable and I want to make about 500-600rwhp. I will drive it mostly just cruising but possibly some road course racing or autox.
I've tired my best to do my research and I've come to the point were I see the merits of two different options but don't know which one would be better for me.
1. Build a low compression (8.5ish:1) setup with plenty of airflow and run that while I save up to add a twin screw supercharger. I know until I add the supercharger the engine will be under performing, but when I do add the SC I won't have to replace half the new parts.
2. Go full NA. I would use a stroker kit to up the CI to 408 and add on all the necessary extras (custom cam, headers, intake, etc.)
I know that the supercharger set up can easily meet my goal, but since the stroker kits can be configured so many ways, I'm not sure what would have to go into it to get to my goal.
Again I want to be reliable more than anything, I know that I will give up some of that with the higher HP. I want to use a T56, probably going to use Tick for a stage 3 rebuild, and put a MWC 9” rear in it. I'll also be redoing the whole suspension and brake system, if it matters.
I have looked in the couple of junk yards around me and I'm not able to find any decently priced LQ engines, bare block to complete, most are in the 2k range without ECU or accs. This has made me much more inclined to go straight to Texas Speed to have them do the build for me. I fall into the “buy once, cry once” school of thought, but I also don't like to waste money on something that is far more than what I need.

Tl;dr NA stroker or twin screw supercharger to get an LQ up to 550rwhp

I'll get pics up soon!
Thanks

 

8.5 is pretty darn low. I'd imagine E85 is plentiful in SD, you could easily run 10:1 on boost on E85 to net great response for 600rwhp. If on normal pump gas I'd look at around 9.5:1.

Personally, if you plan on racing anything but a straight line, N/A all the way. You are looking at 200lb+ over the nose between the blower and iron block. At the same time 550rwhp isn't budget N/A either.

You can also check out Thompson for an engine. If you can, go a little extra and get the aluminum block. That's 100lb off the nose. You can do an Iron 427 for 3900 base price or an aluminum 427 for 4800. I say 427 only because the price difference between a 402/408 and the 427 is less than $200. Seems like a no brainer. :-)

The 427 can easily make the 550rwhp you are looking for. 402 will require really nice heads and a big cam.

But it's easy to spend someone else's money. 100lb for ~$1000.

LS3 based 427 $4800. No need to upgrade anything unless you have big plans later.

LQ9 427 $3950

 

I'm no fan of nitrous, but you could build a budget friendly 6.0 with ported 243 heads and a good cam to get you into the 430-450 range and then hit with nitrous when you need it

 

Drop the newb thinking, start learning THEN LATER come up with a plan.
You are off to a bad start, talking too low a compression for boost and failing to mention the most critical part of a NA build which is HEADS.
Also 500rwhp is a real handful in a true street car, a 400rwhp on rue street tires will often break the rear loose for a second if you punch it at 45mph

AutoX with 500rwhp would be a huge handful.

Find a good condition junkyard engine and slap a cam in or maybe heads and cam and begin to learn. Sure some will argue that wasted money since you will likely buy another cam later BUT I would argue getting a clue will be worth the cost now and help you a whole hell of a lot down the road.

 

You're not fitting a twin screw under the cowl unless you hack up the car. So, you're looking at a turbo or a centrifugal supercharger.

You could run a stock 6L motor with a D1SC and make 600rwhp all day (and I'd rather run a 10:1 or 10.5:1 to keep it from being too soft - so the LQ9 is what you want with 10.5:1 CR). Then you could forge the motor, upgrade the fuel system, run a custom cam and aftermarket heads, and swap in an F1R and make 900rwhp all day. The cost goes up quickly as you have to build the rest of the car to survive that sort of power.

Or you could run an LS3 based stroker (screw iron block) and run Frankenstein ported TFS heads or All-Pro Small Bore LS7 heads. Run a Cam Motion Low Lash Solid Roller, shaft mount rollers, and either a ported FAST or run a single plane manifold (hack away on the cowl). You can hit 600rwhp all motor with that. Then add a 300 shot of nitrous on top of it.

Which one would I rather drive? 600rwhp NA motor all day that spins to 7500+. It'll whoop a 600rwhp centi blower setup... and it won't even be close. Hell a 700rwhp blower setup won't take that solid roller 418. There's something to be said for a well sorted stroker LSx motor. Especially once it's on nitrous. Would I daily drive it? Yes. I daily drive a big cam in a 346 and a 4000+ stall. It is what it is. But there's something about being in such a raw and insane vehicle.

 

Boosted setups aren't for everyone, on paper they sound nice.. And you can make 700-1000 hp

However most cars making that power usually turn into track cars and are rarely daily driven.

Let's get real, you won't be driving a 800hp pro charged car around to do some errands. Maybe once or twice but it will get old fast.

Also they are harder to find a competent tuner to actually make it drive able vs a NA setup which can be done via mail order if need be.

They are more of a commitment and usually for the most part can't be done overnight as a NA build can be done..

Idk it comes down to preference and how you plan to drive the vehicle.

I'd rather have a NA build as id like to drive it 4/5 days a week

 

Thanks for all the replies!! This is exactly what I wanted to see, I can read about other people's projects but not sure what to do for mine. Just to add some additional information to the mix; as Exidous said, E85 is common here and I have thought of using a flex fuel system. Also, this is going to be a weekend warrior that may see a track, it won't be a daily driver; I have a grocery getter. Up here there is plenty of open roads and an 80 mph speed limit Honestly, the quarter mile doesn't really hold any interest for me. I like to go fast, but honestly I haven't been in any big power cars before so I may be plenty happy with 400rwhp. I do have a habit going a bit overboard, ask my 12" surround sound speakers

I do like the idea of going N/A and adding NOS so that there is more power if I need it. And the reason that I looked at the LQ blocks was that there are so many that have been swapped in and it is easy enough to do. Would there be a lot of extra work getting an LS3 in?

Just to get my head around this better, when you say true street tires, are you talking about something like all seasons, or something like nitto 555r's? Because the car is going to be driven exclusively in the summer and I was planning on using r compound tires on it.

Again you guys rock! Thanks!!

 

R compounds like the r888 are a lot of tire for the street and while they will hold a lot of power they have a very short life span and not good in the wet.

I have some 255 wide 180 treadware tires that held 420whp in 3rd and almost 2nd. I'd say a 285/295 180 tire will work well enough on the street. 1st was useless.

It depends on which LQ you are talking about. A Gen IV LQ9 and LS3 will be pretty much identical minus block material, they both use a 58x/4x crank/cam. A Gen III LQ9 will use a 24x/1x crank/cam just like an LS1.

500whp is indeed a lot of car on the street. I'd say anymore than 550 just becomes a straight line monster. A guy on another forum was at over 1000whp and used to road race. One day he had belt issues and raced most the day N/A(in a car meant for boost). Roughly 475whp. Said it was more fun than he had EVER had with 1000whp road racing. Sold off all the boost stuff and built a stout N/A motor. Never looked back.

 

Personally, I like the way a good H/C/I car drives. Especially if you plan to drive it every day - or even just a few times a week.

I just see so many people immediately go to "stroker", and very often would hit their goals with a stock, used 6.0 bottom end, good heads, well matched cam, good intake and exhaust, and a good tune. You don't need to spend $8000 to have a fun LS car

 

I vote 600rwhp D1SC setup. forged 347, LS6 cam, stock 241 heads or stock LS6 heads.
It'll drive like stock and sound like stock (except for the whistle from the D1SC), still be "peppy" when your not in boost and have to power to run 10s@130mph+

NA is fun for awhile but you ALWAYS want more. Daily driving a 600rwhp NA car with its monster cam and stinky exhaust will get old real quick. Plus a 600rwhp NA setup is pretty much tapped out with the best of the best components, high compression, monster cam etc.

A forged 347/D1SC will allow you to have anywhere from 450rwhp up to 600-650+rwhp with the stock 241 or 243 heads. If you want 700-800rwhp you would need a set of good heads and a nice medium size blower cam.

Here, read this thread. KP has experience with both. Big NA stroker and a mild 347 with a D1sc. You'll understand what Im talking about.

https://ls1tech.com/forums/forced-in...ighlight=solid

Ill also say 600rwhp on the street is down right wicked fast. When I had my forged TT setup, Id kick it down from a 60mph roll on the highway and it would start skating. Talk about scary. I turned the boost down to 10psi which was about 500rwhp and it was alot more "manageable" on the street, and still plenty fast.

 

How fast do you want to go exactly and how much money do you have to spend?

A fast street car is quite subjective depending on experience and who you are asking.

 

This^

Could easily be a 20k project with a new engine, blower, fuel, rear end, trans... Etc...

 

Well he said between 500-600whp and possible road course without much interest in drag racing. Anything but alum block N/A is a lot of weight over the nose.

 

The argument can be made that a Procharged car would make a better "daily driver" then a heads/cam/bolt on car. The beauty about a Procharged car is that it's going to be very docile outside of boost and it's going to idle like stock (if you keep the stock cam, or a very docile blower cam). Now, if you throw in a rowdy cam with the Procharger, then that would negate the aforementioned. I bet you the Alchemist would argue that a Procharged car makes a better daily driver then a heads/cam/bolt on car.

If you're looking for between 500 and 600 whp, you can do that with bolt-ons and a D1SC Procharger and have a very friendly daily driver.

 

HP is just a # for dick measuring contests....a tangible performance goal is a better measurement; like goal is to run 10's, be competitive with car "X" on a autocross course, or outrun a Hellcat for example.


OP also could run a rear mount turbo kit and not add much weight up front as another option to supercharging/front mount turbo. More research and a budget is needed by the OP regardless.

 

The goal basically comes down to: I want to have a car that I can use road racing/ auto-x/ taking corners fast and still have the power to go faster than most production cars and keep up with other modified street cars. The quarter mile times don't matter to me, I'd much rather have fun hooning around on the backroads.

Budget wise I'm not sure. I guess to start I'd say keep it under 10k for the longblock, and power adder if there is one.

 

10K is plenty for a short block/power adder..... in that case, just $1400 more will get you 556HP LSA supercharged crate motor with factory warranty and free shipping lol....DO IT! A simple pulley change and CAI and you'll be knocking on over 600HP with stock drivability

Very heavy though, or just go all out and spend 13K on a LS7 and put a cam in it.

 

On my Caprice with based on performance at the track something a bit over 400rwhp with 255/50/ZR17 tires UHP summer only daily driver performance tires if that makes sense it can momentarily break the rear loose at 45mph, not out of control, just enough to dust off the tires and then grab. 4150-4200lbs raceweight, 11.5-11.6 at consistent 115mph with a couple passes at 116mph at 500ft DA.
The chassis is pretty much like an old Chevelle, splayed 4-link simple and easy. At the track I just slap on a pair of 28x10.50 ET Drags a wrinkle wall bias ply slick. I could have gotten a little more mph with a radial and maybe a 26-27" tire but this is simple and dead reliable, on a good surface( Union Grove) 1.5 60ft times lifting the nose a couple inches.
500rwhp is enough to tickle 9s in a well setup f-body, mid 10s in a porker like mine.

400-450rwhp is enough for most folks on the street.

 

I'll give you my personal experience on this... Flash back to 2005, i built a low compression (8.8:1) forged 347ci motor and slapped a D1 procharger on it. Car made 540 hp on 10#'s of boost. It was a dog out of boost and I didn't care for the way the car drove unless it was 4k+ rpms. Car had MTI worked 317 heads, blower cam, full exhaust, and ls6 intake manifold. Fast forward to 2012, the car sat for 95% of the year and I wasn't into it much at all. Pulled the motor reused the block and the rods and built a 383ci 10.1:1 compression bottom end. Reused everything listed above, same blower pulley too. Redid the intercooler/plumbing, added meth injection and a few more little mods. The car made 616rwhp and 566 rwtq on 8 #'s of boost. Only thing changed was the compression and 36 extra cubic inch. The power gained under the curve is intense, I love the car again. Part throttle and out of boost driving is crisp and fun again. Then it gets crazy at the 3,200-3,500 rpm mark when the boost comes on. Car makes 500 TQ at 3,800 rpms. Had all intentions on pulleying the D1 to max this summer but the ram clutch decided to give up the ghost about a month ago, so now I'm saving for a new clutch.

So after all that I would recommend building a nice forged stroker and keep the compression in the 10-10.5 range, big exhaust, drive train and fuel system first. See how much money you have then go forced induction from there. For your driving needs you want a good part throttle and off boost car. I am also in the same boat, My car is 99% street car. You can still enjoy the car until you have the budget for forced induction and then add 2-3 hundred HP to the mix.

Good luck.

 

Did I miss what the budget is?