Hi not sure if this should be in tpi or power adder

I want to make 400+ fwhp with one of the following options. Any input or experiences are appreciated. I do want to keep tpi long tube runners (stock, edelbrock or first). I currently have a LB9 with full exhaust and paxton producing just over 7 psi ( don't hate..... in 89 formula


1) get a half decent crate engine or used 350 with either stock or edelbrock intake runners with right cam And head combo ( to make 290 hp?) and keep paxton with 6-7 psi. My budget would be 2500 cdn and work supplied by me. Not sure what combo I can do for this budget

2) build new 383 get rid of paxton. The set up would include first intake, blue print heads muscle series 64 cc 202/160 and not sure on cam. Budget on this would be 4500 cdn

I will be keeping stock ecm with custom prom

Thanks for any input

2

you can do it but not on stock tpi...edelbrock at minimum or mini ram or hsr might be way better.
I would build a 350 with the sc since you already have it.

Never seen anyone wanting 400+fwhp, usually rwhp. 400 flywheel ain't hard to do. You should be making this already with the Paxton at 7 lbs right?

Unfortunately I don't think so. I haven't been on dyno but 14.5s 1/4 mile tells me I am nowhere close. Just picked up slicks so maybe I can drop a few tenths.....
I think right now I am 310-320 fwhp. My afr is 10.5 at wot so I think if I can lean it out a little I can do a little better. Lb9 with peanut cam sucks
I have read about some tough builds so I am trying realistic with a long tube intake hp expectations
Thanks

What is your quarter mile mph? When I was around 300 rwhp my mph and et was like 12.50-90 with a 105-108 mph but can't remember exactly.

Based on memory 98.xx mph
I think I have 300hp at motor not wheels....
Still sucks for me

If you're looking for reliability there are multiple crate engines that come with 400 fwhp. No guessing, just a little bit of tuning and everytime you turn the key - bang - 400hp. Depends on your budget though.

Your engine made 195 horsepower stock. Running your Paxton at just over 7 psi will net you half of your engines baseline horsepower, 97.5, giving you 292.50 FWHP. Assuming your car weighs 3500 pounds, 292.50 horsepower should net you 102-mph in the 1/4 mile at that weight. You stated you remember running a tad over 98-mph, the 4-mph difference is more than likely either in your tune, maybe in the weight, could be from the gear swap (your profile says 3.73's), maybe you eased off the throttle, etc, could be anything. Getting to 400-FWHP isn't too difficult, just up your boost pressure to 15-psi using a different set of pulleys while tuning for a larger set of injectors. Or go with a better head, cam, intake and injector combo netting you 265 horsepower as a base instead of your factory 195 horsepower, while maintaining that same 7.5-psi of boost pressure from your Paxton, as that will also give you your 400-FWHP number...

For 400 hp i would go na build all day over any boosted setup. Keep it simple...

Even 400 whp isnt hard to get these days with a good head cam 350-383. But budget will decide what u can do

Stockish motor with blower kit for those powers can work well too if you dont want to build a new motor

How old is the current motor? If you do heads and cam now I would try that first should get you close without pulling motor out.

You can make power with the long tube runners but you need to stage out your plans based on the rpm limitations of the runners. You can't go wrong with the lpe 219 cam for low end and mid range torque. Send the heads to Lloyd Elliott for porting or get some used heads and you should hit your goals with the blower. Stock ecm might be a limiting factor though.

Honestly, if I were going to try and do this for the minimum investment possible it would be getting a cam/valve springs/timing set and porting out the base and plenum, add runnersthen adding a meth kit and a pulley if that didn't get you there.

If you want to keep the TPI anyways throwing a decent set of runners on is something you can do now as well. I would look for a used set personally as you're out of minimal money if you decide to up the ante on your intake later. Expect to have to pulley up to maintain boost levels/increase power as you increase flow through the engine.

Lastly, how much timing are you running? Fueling is the most documented when it comes to tuning, but timing is the key to power.

i made 381/420 to the wheels with my 305 TPI with 10#'s on the procharger, i upped it to 14# not sure what i'm making now..

you need to tune and get a decent cam

my stock vette motor with 6psi paxton gets me 340 rwhp and the dyno guy said its about 400 at the flywheel and just bolt on parts intake runners tb headers

Hi
Thanks for the replies
To answer some questions my lb9 is original stock 89( some blue smoke on startup)
My timing is base at 6 btdc. My afr is rich at wot at 10.5
I think tune will definitely help. I am not crazy about dumping more money into the 305 it just seems like a difficult route to 400 fwhp with not much future potential

After spending hours reading posts I am leaning towards 383 with vortec base and vortec heads. I will keep stock plenum and throttle body and maybe upgrade to asm or edelbrock runners (not sure about cam). I will also keep paxton and hopefully maintain 6 psi boost. Any ideas on fwhp??
I am fairly sure it will be above 420 fwhp.

Any more feedback is great
Thanks again

You'll have to change pullies on the SC to get the same boost pressure.

Give us an Update ....




















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Plan is for build over this winter

383 with eagle rotating assembly from summit
Staying with 2 bolt main and single piece seal
Sdpc vortec intake
As&m or tpis runners- looking for used set
Stock plenum and throttle body
Vortec heads from sdpc with .525 springs
30 or 36 lb injectors- not sure yet leaning to 30lbs since I already have them
Cam not sure - I would appreciate suggestions
I will be keeping paxton sc with 6-7 psi plus water/ meth injection
Upgrading fuel pump to walboro L98 kit from racetronix
1.5 rockers

Any input is appreciated



















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If you're going through this much work I would recommend going with a 4-bolt main block.

And before I get flamed - I know, I know, there are plenty of 2-bolt engines out there pushing xyz hp and abc torque....

But, why not start with the strongest foundation? In the grand scheme of things it won't cost that much more.

Sounds like you want a 4 bolt vortec truck block with a 383 kit in it.

30#/hr injectors are small. Here is the 100% DC calc for crank HP at stock fuel pressure+6PSI : 8*30/.58 = 413 HP. Suppose your new 383 makes 450 crank hp. At 6 psi, the output is 450*((6+14.7)/14.7) = 633 crank hp. Let's pick the injector duty cycle to be 85% : (633*.58/8) / .85 = 54 #/hr

Two other points
I am keeping all emissions stuff- it is required here for 89
With regards to block I mentioned 1 PC and 2. Bolt since I want to use a 88-95 roller block which will allow me to swap over serpentine accessories and paxton support bracket (4 bolts to block by memory).

If any other 350 roller block will work I would be interested
Thanks

Update
I installed my 383 vortec heads, with cc 269 camshaft. The engine produced 430 hp and 480 ft lbs peak numbers. The engine did not have accessories or ltr. The dyno run was with a 750cfm carb and rpm performer intake.

Now I am installing my ported accel runners, sdpc intake entry porting and ported plenum with stock throttle body and air foil

Question any estimates of fwhp and torque with accessories and long tube runner set up ?

I know this is old. Finally took car to track- just to close loop on this thread
my 1/4 was 13.5. I think with a few more passes I could probably drop 0.2-0.3a