Hey everyone! My build is almost complete! It's a 1999 WS6. I originally had a 1998 Firebird that was essentially a cam only car. It had a ~3200 stall and a moser 12 bolt. The AC blew Ice cold and this car got me everywhere and never skipped a beat. It ran a best of 12.49 in the 1/4 mile. I had this through most of college and had a lot of fun with it. It had 180,000 miles and I knew that it was time for something with lower miles. I ran across a 99 ws6, 6 speed car with a ls1 383 stroker. This car had 35,000 miles when I purchased it. Piston 5 and 6 were fried so I pulled the motor. The block cleaned up at 10 over. The Lunati crank and rods were salvageable but pistons are not. (Block, crank, and rods are currently for sale as well, PM for details). I decided to re use a lot of my components and build a better setup for a street car with some time at the track as well as a setup that could handle a 150-200 shot of nitrous. What I decided on was a Texas Speed 418 cubic inch LS3. I decided to re use my 244/248 cam with a .612/.615 lift at 112 LSA. I also decided to use my extensively ported 317 heads. They have been angle milled and yield 54cc. I am unsure on what my heads flow exactly. I went with a -20cc dished piston as well to keep my compression at a conservative 11.1:1. I also went with a fast 102 intake/Nick Williams 102 mm throttle body setup as well. I'm reusing my Grotyohann long tubes and my single 4 inch exhaust that dumps behind rear axle. Also got some fresh injectors that flow 42#'s. Power is pushed through a TH400 with a PTC 3600 nitrous converter, steel driveshaft, and a ford 9 inch with ford 3.70 gears. 325/50/15 tires in the back as well. A little bit overkill but they look mean. I have adjustable shocks all around, tubular front K Member, adjustable rear lower control arms, and a Wolfe 6 point cage. No AC, no rear seat, no front/rear bumper support. I'll be breaking this motor in about 1000 miles before I hit it with N20 and a dyno tune. For the first 1000 miles it will simply have just a good road tune. I'll have a stand alone system setup under the hood to activate when my N20 system is activated. This car is garage kept and will be brought out Saturday nights and Sunday's on the street to have some fun. It will see some track time at Kennedale, Tx/ Denton,Tx (both 1/8th mile) and hopefully Ennis, Tx for their 1/4 mile. I'm hoping to run consistent low 10's and potentially break into the 9's with optimal weather conditions and skinnys up front. What do you guys think I will be looking at power wise? Horsepower/torque at the crank and also at the tire? As well as track times? I'll get some pics posted soon


Thanks,
Patrick

 

Sounds like a cool car with a great history!

What size intake & exhaust valves are in the heads?
Who did the extensive heads porting?

Often TH400's seem to soak up a fair amount of up.going from engine dyno flywheel numbers to rear wheel.

The Grott headers are 1 3/4 primary or 1 7/8 primary? I would defiantly want 1 7/8 for the 418 engine.

 

U might want to think of stepping it up to a 2in header

 

I would definitely do a 2" header. Just curious what is the quench at on that combo?

 

I do not claim to be an expert, but I would suspect mid-10's N/A if you get it to hook.


I have a 2000 Camaro - stock bottom end, PRC 2.5 ported truck heads, TS Torker V3 cam, all stock induction (terrible for this head and cam combo, but will be upgrading shortly), no A/C, air pump, EGR, ABS or CATS. It has a less than ideal tune (will upgrade after the induction is upgraded), runs through a Performa Built Level 3 4L60E, chromoly driveshaft, 10-bolt with 3.73, Spohn pro-series torque arm, 3700 stall converter, basically stock suspension with UMI non adjustable lower control arms and panhard bar. I run M/T pro bracket radials (full slicks), skinnies up front and launch off a trans brake at about 3500 rpm.


Best run has been 11.692 with a 1.62 60ft. Car weighs 3550 with me in it. I would think your combo should be nearly 1.0 better than mine without nitrous.

 

Intake valve at 2.055 and exhaust valve at 1.600

Unsure about quench

Unsure about header size

My converter does seem a little tight on my old 383 setup before those pistons let loose. It's a 3600 nitrous converter so I feel as though it locks up entirely too early when in running strictly motor. I feel as though low tens and high 9's on a 175 shot is pretty achievable outside of the 100+ degree Texas summer nights. Should net me around 500rwhp on motor and maybe 650+ on the bottle. I don't care much about horsepower, Timeslips are more important to me 😎

 

I agree with the others that 2 inch primary headers are probably best for your application.

High to mid 10's NA
Low to mid 10's on 150 shot
Depending on how the car hooks up.

NA dyno 465 & 600+ with the 150 shot. I think the car will run well at the trackas expected but dyno a little bit lower than expected with the TH400 & NOS converter. I think 1 3/4 primary headers will hurt performance at the track and at the dyno.

Just guessinguessing. Let us know the results.

 

A 244/248 112+2 can be an excellent selection for your build. I would run it.

 

The car is back together. I have ~250 miles on the rebuild. I'm aiming to put 1000 miles on the car before I spray and race it. My rear tires are 325/50/15 and they are rubbing a bit over bumps due to the Eibach Pro springs lowering the car ~1.2 inches. I'm thinking about either going to a 275/60/15 tire OR going back to the stock springs. The tires look great on my car so I might go for the stock spring. Even with a passenger in the car and no bumps, they leave less than a quarter of an inch of travel between tire and car. As far as moving forward, I plan on buying a new exhaust system. My headers are old and beat up and I've been told by many people that they will hold back my dyno numbers and track times. A 2 inch header would be the best fit is what I'm told. Kooks makes a header I think might work for me. Part #: 22412600
Some advice here would be great.

My current setup is headers to a Y pipe with a single 4 inch exhaust that dumps right over the rear axle. Due to the ~25 degrees of overlap in my cam, the unburnt fuel finds its way into the he car and makes my clothes smell like gas. I want something that goes all the way out the back of the car I think. My setup is a little too loud right now as well. Maybe the 2 inch header to a x pipe with dual 3 inch towards the back with a bullet style muffler/resonator then exit right under my rear bumper.

Im also contemplating getting skinnys up front 17 inch is ideal because I would like to grab bigger brakes in the future. Unsure on what brakes to go with there. Also looking into a HID headlight swap.

As for now, the car runs good. ~6.5 gas mileage due to the simple street tune and I have some surging issues every now and then.

 

Even with my true duals that went all the way out back and 17 degree overlap cam I had fuel smell on my clothes too.

Lean it out at idle since that's where the dumped fuel clings to you and then reduce timing a bit so you don't get the NOx smell either. It's worse. And it comes from advancing a cam a lot. It's amazing how little timing is needed at idle for it to work.

You can also change the EOIT a bit so you delay injection and make sure you get a more complete burn. You'll be able to drop your fueling quite a bit at idle by doing this. All of these things will help.

 

Making enough compression with a thin gasket, tight quench and using a dished piston should work in your favor, the dish allows a bigger intake charge, should run very well with the right tune.

 

the car was finally put on the dyno. I recently upgraded to Texas speed 2 inch primary Longtubes as many people told me I should step up to them. I also went with the Texas Speed True Dual Rumbler setup. It contains an X pipe then two resonators and is dumped before the rear axle.

Regardig if dyno numbers, I feel as though they are a little disappointing. My power curve on motor seems to die at 6000 Rpms. Maybe it's he heads?? I would hunk they would be the weak point in this build. I know my setup won't show high numbers due to the big converter, TH400, and 9 inch. Enough on all of that. on motor alone peak power was right around 6000 Rpms. It made ~455 horsepower there. On a 100 shot and spinning to 6000 Rpms again, ~550 horsepower and 515 ft/lbs of torque. I'll be MAKIG some passes this weekend I think. I'll keep you all in the loop

 

U should still come close to your goals. A buddies car had a 370 ls3 head lq9 in a full weight trans am and made 460 thru a TH400 and a 9" with 4.10's. Ran 10.60's, raceweight was around 3500. The track will tell you all you need to know. That nitrous stall might hold you back when running it NA, This car was cutting 1.4 60's

 

Cam needs more exhaust and needs to be advanced. I would have done a 244/256 114+3... it would carry better even if the heads suck.

I have a 227/244 115+5 cam that carries to 7200 in a 347. For a 408, it would be about 10 degrees bigger ~ 237/254 115+5. But as it stands right now, my cam opens the exhaust valve earlier than yours in a smaller motor. And to breath uptop, your exhaust valve has to open pretty damn early.

 

The car has been running pretty good. I've been taking it to a few local 8 mile tracks around where I live in Dallas Texas. I've been making quite a few passes on motor and also on my 100 shot of nitrous. I've been testing out watching off of my foot break, off of the two-step, and also off of the transbrake exclusively. On motor alone, my best pass has been 7.14 at 96 mph with a 1.52 60 ft. My best pass on the bottle has been 6.59 at 104.5 mph with a 1.42 60 ft. I'm having a few issues with fluid spewing out of the vent tube at the top of my transmission. I recently installed a catch can on the bottom of my transmission pan from ATI. The scavenges excess fluid that shoots at the top of the transmission into a small catch can. The car still seems to be smoking when I go through the trap. I imagine it's due to extremely high temperatures in the transmission as well as due to the high stress that is being put under. I've talked to quite a few people and everyone tells me I should upgrade my heads. I recently priced out some options with Derek at Texas Speed. Please see attached pic and look over my specs and give me some advice you guys think. The issue is that with my current 317 head with 54 cc chambers I used a -20 cc piston on my 418 to keep my compression at 11.1:1. With these PRC 247 cc cathedral port heads Milled to the lowest amount of 62 cc my compression would drop to maybe 10:1. I would need to angle mill these heads to 54 cc for this setup to work. Also my current cam has 22 degrees of overlap and this new one looks like 28 degrees. Will that be an issue? Contemplating upgrading my Current lid to a 104 mm as well as a 100 mm MAF sensor. Any and all suggestions will help! Thanks!

 

According to the ole trusty wallace racing calculator, your 455hp at 11:1 will only fall to 450hp at 10:1. Considering those 247's should flow better you probably wont lose much power at all and with that cam should be able to carry the power higher. Are you really running 1.8 rockers though?

 

Good to know. I would be okay with a small power loss like that. It would enable my motor to last a little longer as well I would think. I don't think I'll ever spray more than 250 on this setup. It's set up for 100 shot for now. What kind of gains do you guys think I will make? I'll use 1.7 rockers by the way

 

Without knowing your current CC and headflow its all just a guess on power figures. My best guess would say that the person who ported your 317's shot more for flow under .500 since it was more of a street car and thats where it lived most of the time. This could also be why you peak at 6k. Or you might be running out of injector and/or fuel pump. I built a SBE LS3 with a 235/243 cam and tsp 243 2.5's for a buddy and his 42#'s were at 96% at 6300.

 

Just out of curiosity, did you ever end up going with the larger cylinder heads and camshaft? Currently I just purchased a 418 ls3 from tsp and going to throw my as cast 225 heads and fast 102 on the motor until I can afford to do something with a better cylinder head. I am going with a 10cc dish as to keep higher compression with a 62 cc chamber. Just wanting to see some real world results!

 

LS3 w/ 225 as cast TFS or AFR = torque monster