Im building my 88 at the moment and i have a 454 +.030 goin in. Going to be around 450-500hp @ the wheels. Going to run a TH-400 and either 4:11's or 4:56's posi of course. Will i be able to take most ls1's?

 

You are going to lose alot of power to the rear wheels with a turbo 400.I think you will need around 600hp to get that kind of rear wheel hp.Turbo 400's cause more drivetrain loose.25% to the rear wheels is very common.If you could I would run a built turbo 350. There are many companies or tranny shops that can build one for under a grand (less converter) that could handle the 454.Of course if you plan on running more power later on the 400 would seem the right choice.Either way 550-600hp at the engine is going to be needed for those rwhp #s.I assume it won't be a daily driver?To answer your question, I have seen several LS1's run low 12s with just bolt ons,sticky tires and a converter.Once the LS1's have heads and cam swaps it will be alot closer.470-500fwhp is not uncommon for daily driven LS1's with a cam and head swap that run 11s and they are not even stroked or bored out.But a stock LS1 you will destroy.It just depends on what is done to the LS1.I would say 90% of street driven LS1's would lose to that kind of power.

 

Thanks for the input. Ill will be eventually putting a blower on it (reason for the 400 ). And yes its going to a weekend car considering the mileage it will get. I have a 4x4 thats my daily driver.

 

a heads/cam LS1 would take that motor no problem

 

a heads cam ls1 with a 12bolt or 9 inch rear large convertor and slicks maybe... but the vast majority of road going ls1's would take a dive.

 

turbo 400 uses 44 hp to turn and a th350 uses 36 hp there`s a wieght difference too but I can`t recall exactly how much.

those LS1`s can`t hold a candle to well preped bbc with traction

 

there are cam only LS1s running 10.80s to 11.20s. Then you're talking heads and cam cars putting down 475rwhp, and are lighter by 300 something pounds than a stand alone BBC. I'd still tip my hat to the LS1s. Now a bone stock engine with some basic bolt ons he could take, but a mild BBC has no shot to a h/c/i LS1 or LS2

 

ill be pretty much stripping the car. A/C assmebly, ducts, powersteering, backseat, & wll be running a smaller fuel cell. So i wont gain to much weight.

 

Yep, those ls-1's will likely be biting the dust, unless you forget to put it in gear!

BTW, whoever said it will have a 25% drivetrain loss, that's something like 110 hp with his motor, I'm doubting it.

 

no way my buddy has heads/cam camaro and is makeing 452 to the rear with 450 tq and just put a 12 bolt in it. when we went to the track his 10 bolt took a dive so his a 12 bolt. most ls1 around hear have ***** they will tkae out a car like yours. with just heads and a cam they make like 398 untuned but dyno tuned makes hp out the ***. so use a th350 and get it built and get sticky tires and u will whoop a ls1

 

With that kind of motor? Unless the LS1 is heavily modified you'll have no problem. Though with a big block there's no reason you should worry about a little itty bitty 346

 

Just curious why your building a big block?
1) You can build small block to just about the same hp levels, less torque, but you can get more gear since the bore x storke combonations want to rev higher
2) That big block in there will make it a pain to change plugs
3) Your going to add nearly 200 lbs to the nose of the car
4) Your going to need to fab up alot of stuff like motor mounts to get it to work
5) That big block is going to twist that unibody with ease.

I say build a 406, turbo 350, custom ford 4.56 9 inch or 12 bolt and your good. It wont be too much of a hassle and will be just about as fast.

 

1. Untrue, For the same dollar invested the gen 1 small block will come up way short, if we start talking dollar to HP over 400 HP, under 400 HP the small block will definitely have the advantage.

2. Spark plugs are ALOT easier to change on a BBC, think about it, the ports are all separated were as the SBC has 4 of them squeezed together. I have had a whole gaggle of SBC with all the different manifolds and different headers in my car and it was never a pleasure to do them, now on my second brand of BBC headers for my car and I can tell you this, with a 5/8 hex top socket and a short 3/4 wrench those plugs are all out in less than 4 minutes.

3. You have a valid point here, the opposite side of the coin for comparison however is that an aluminum headed BBC weighs no more than an iron headed SBC...smaller engines will always weigh less than bigger ones, hard to argue.

4. Untrue, the BBC will sit right down on the small block mounts. everything is pretty much a bolt on, there`s no more to be fabbed than there is with a custom SBC install, everything is different so yes you will need to find the right equipment and we all know what happens when you don`t..you try an make something else work. (i.e fab)

5. True, but so will a SBC built to the same power level, the car will need subframe connectors no doubt.

Truth be told, the small engine is cheaper and easier up to a point and can yield great results. But, if dropping a BBC in was easy, cost the same and made more power per dollar would not mostly everyone do it? I`m ran down by small blocks all the time at the track, but if the cards were on the table on what the engines cost to make that kind of power with that cubic inch, I`d be up front all the time. I`m not trying to flame anyone here but I would like to be sure there is no misconceptions of the install or the output of this swap.

Now let`s talk practicality.....

 

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Nicely said Greezemonkey. Ive already modified what i need to using a mock up block so once i get this thing build it will slip right in . Actually, the motor mounts were the easiest part of this swap in my opinion. I wanted something unique...atleast more unique than a small block.

 

A properly built BBC making 500 rwhp would have a hard time finding a street driven LS1 that could compete. Have fun.

 

Never heard of cam/head nitrous combos then... There's a few of em out there...

 

The 12bolt most people have w/ wheels probably takes another 40-50 hp aswell. It adds up.

 

Good Point! I would to see what the 9 bolt, 10 bolt,12 bolt a 9inch all cost to run in HP. Here`s is where the apples are divided from the oranges though, peak torque and where it is made...for example one of my first cars was a 76 firebird, I had abused the pontiac 400/saginaw 4 speed until it was shooting pushrods through the valve covers (no joke). I transplanted a 455 pontiac out of a 72 bonneville into it along with a mid sixties close ratio muncie M21. The rated HP of that engine was 180 with acc`s, the torque was 500 at 2,000. With some sticky firestones and a mild 2,500 launch on nice blacktop, the 10.2 ten bolt broke it welds at the pig and rotated up until it hit the floor pan on it`s first flogging. It`s all about the arm in that engine the longer it is, the more torque...I have nothing against small blocks be it gen 1`s LT 1`s or LS X`s, drop a 4 inch crank in one and now you have something, give it enough air and you have the best of both worlds torque and HP

 

I have always heard a 12 bolt is lighter and takes less horsepower to rotate than a 9 inch, and for the 9 and 10 bolt rears, they would take less horespower to spin because of the obvious reason of being smaller, but more likely to break. But many people have run fast times with them and they will hold up but the question is for how long.

 

A 9" does eat up more power then a 12 bolt...

But what do you always seem to see under drag cars?

 

they have kits for heads and cam combo for ls1's they are kinda pricey but worth it well worth it dont be afried to get 1. but racing them i would be with n02 they are monsters and will beat the hell out of a lot of cars

 

You just confused me

 

Danas!

Haha just messin.

9 inch for the win.