Mikelly

Howdy. I'm Mike, and I've got a car addiction. Really bad car addiction, actually. Anyway, I plan to campaign this next year in NASA TT:




From behind the wheel...




The car most recently had an oldschool 383 stroker in it and we'll retain the TKO600 and the FAST EFI standalone and dash setup for the LS1. The LS1 as of right now is stock bottom end, but we're going to run the ARE 3 stage drysump kit. Also looking to make the bottom stronger.

Targeting 500WHP with this motor and the specs on the car are as follows:
Weight will be 2480 without driver. Tire size is 25 inches. Final drive gear is 3.54. I'll be using a set of custom long tubes for this build, 1 3/4 primary tubes. The Zcar has a bit of tight fit for exhaust so we're just going to keep it simple from there back. No cats, and only very small bullet mufflers.

This is NOT a street car, although I do have antique tags on it to drive t car shows, or to do basic safety checks on it before events. So there is zero concern for emissions or smog.

So guys what would you build this LS1 up to?
Mike

garygnu

way cool car !you will need some after market heads,consider Trick flow 215s,Air Flow research 210s,or Texas Speed PRC 227 .get a custom cam from Pat-G.get a fast 102 intake with matching TB.maybe use a electric water pump.you should resize the connecting rods if you install new rod bolts.most after market heads like roller rockers.you will need some #42 injectors

bjohn

iTrader: (2)

Hey man, BADASS car! Whats your build idea thus far? Target powerband?

Mikelly

Thanks guys... I don't expect we'll rev this motor past 6800RPM, and since it's a road race platform, the powerband should be between 3500-6500 RPM.

I know everybody is hot on torque and I'm not downing it, but want to make sure we don't lose sight of the weight of the car. At 2590-ish pounds it was making over 480#ft. of torque with the 383 stroker. So I'm good with peak torque and HP numbers in the 450-500 range. Obviously broad flat torque curve is optimal for a roadrace platform.

Mike

Exidous

iTrader: (11)

I'd continue with the 383 in the LS1 for a great tq curve. I don't know what your budget is but I'd get a hold of Tony Mamo and see what he suggests by way of heads and cam.

The LS3 injectors are a perfect size for your target power. Like said some AFR 210's and a mean custom cam on top of a 383LS1 will make a bad *** motor. Just make sure to get some good lifters (something better than the OEM like comp or morel) and springs. Better rod bolts with the stroker kit of course.

95ONE

iTrader: (1)

Mike, I'm sorry but you will have to just give up now. I'll be in your class if you're in NASA and I don't think it has a chance. LOL J/K Your build is awesome and in the exact same spirit as mine. Besides, there's a guy with a well sorted corvette and talent to drive that crushes most everyone. I love the chassis choice. Fantastic Job. Unfortunately, (or fortunately for your budget) you're going to have to cut your target power back to around 457whp to barely make it in even the top tier TTU (unlimited Class). It's power to weight ratio limited 5.5lbs per hp without any restrictions and your weight adds a few to that number. (.30= 5.80lbs / hp limit) - so Assuming you weigh around 170lbs, gives you a total weight of 2650lbs divided by the aforementioned 5.80lbs per hp = 457 max wheel hp. .. So I can tell you to not worry about any extreme engine set up at all. - I plan on different classes and will just restrict timing for less power in the TTU class and bring it back in for other classes. 450whp is happening pretty consistently (With every bolt on) and doesn't seem to merit the need for anything more than a stock bottom end.

Snkebait95

iTrader: (16)

This car is bad.

FASTFATBOY

iTrader: (23)

That little weight it doesnt need a 383, cam it accordingly for the midrange power you want.

Small CC LS6 head CNC'd (call Ai)FAST and an Ai cam will do you good.

Mikelly

Thanks for the comments guys. I'm currently convalescing after hernia surgery on Friday. I'll digest all of this and make a decision over the next few weeks.
95One, My other car is a 2004 Porsche GT3.

Mike

95ONE

iTrader: (1)

I had Hernia surgery 2 years ago; Laparoscopic. It wasn't bad at all. First 3 days was lots of sleep. But I was up and walking around a little the next day. It wasn't the pain that stopped me. It was the lack of energy. Your body will be working overtime to heal up, so let it rest when you're tired. Another thing I think I did too much of was stay hunched over a bit too long. I think you need to keep straight and let it heal that way. It might hurt a bit, but you won't get as many Ghost pains after you've been walking around straight and normal for a while. The great thing was that I learned how to build computers while I healed. It kept me very busy.

Awesome Porsche! Any build like this Datsun, or something like it, certainly isn't cheap. Usually there are other nice horses in the stable. I'm the exception to that - Dodge truck and a Subaru. My NSX is long gone over a decade ago. I do miss that car.

In the mean time, you will have to find out what class your car is going to run with NASA Time Trials. TTA might be allowed, but I'm very sure with that V8 swap, they are going to immediate throw you in TTU, don't pass GO, don't collect your $200, Go directly to TTU. I was a little wrong above in my calculation. If you weight 170lbs, the car will be penalized an additional .30. Not .35 - So I corrected my math in the above max wheel h.p.

A little guidance help from me though. All of NASA is weight/hp based. If you're going for any more wheel H.P. than 350, You're going to have to be in TTS, TTU, or TTR. Those are the only classes that allow any real power. A new statement for TTA - which is the fastest of all the regular Time Trial classes TTF-TTA quotes this rule,

"The minimum “Adjusted” Weight/Horsepower ratio (defined in Appendix B) for any car in TTA is 8.70:1, regardless of how many points it has, or which base class it begins in." Doing quick math, that only allows for a 2650lb car to have 305 whp.
The other "b" - "f" classes require less power as stated in the rules appendix
TTA 8.70:1 TTB 10.25:1 TTC 12.00:1
TTD 14.25:1 TTE 16.50:1 TTF 19.50:1


So clearly, to be allowed any more power, you will have to run in the TTS,TTU, or TTR classe. TTR is for dedicated Tube frame racers , so no need to think about that class. TTS is for supercars with OEM engines only. That only leaves us with TTU. It is the only class we can compete legally in.

Here is the source of my info for your reference (Which you probably already have) http://www.nasaproracing.com/rules/time_trial_rules.pdf

Have a safe and Fast recovery.

Mikelly

Unfortunately mine wasn't laproscopic. Ugh. Fortunately I was able to walk around a bit the day after the surgery. Went down to my shop which is 300 yards from the house, and then walked to the end of my driveway the 500 ft. and back to the house. Saturday night was the absolute worst. Pain was really bad and I had to break down and take the Oxycodone to get thru the night. But today I feel pretty good.

So assuming a 200# driver with my coolsuit system and fire system installed I expect the car with me in it to weigh 2700 pounds. I will have to calculate the power but if you're thinking 420-430 wheel HP will be over the limit, that's not a bad thing. I'd rather have to much and dial it back. Maybe I'll just keep the LS1 and put strong rodbolts in it and go with new rings/pistons and start buying the upper half of the motor.. I've got a Nick Williams 92MM Tbody on the way, and have a Z06 intake I can port. Hmmmm... Sounds like heads/cam/rockers and I'm ready to rock and roll.

We're using Fast XFi with Traction Control System...
Mike

Mikelly

These came in today. Custom built specifically for the Datsun 1975-1978 280Z chassis. $1215 shipped.

95ONE

iTrader: (1)

Not laproscopic!? Oh wow. Don't push it. Hang in there.

I was calculating 457 wheel HP. But if you get the car over 2700lbs you will be able to run around 460-465whp. That's quite a bit, but doable on a stock bottom end.


Very nice that someone has something made for your application. Awesome.

Mikelly

Gonna get with Patrick-G and coordinate a cam grind/valvetrain and possibly head selection. Email back and forth with him the other night, so I need to go ahead and fill out that form on his vendor site and get that going.

Mike

95ONE

iTrader: (1)

He's a cool guy. Was very helpful. Good direction. Just be sure to KNOW your class and power to weight rules before you start. I can't express that enough.

drivinhard

iTrader: (1)

Actually most of that is changing for 2013. TTA is gone, replaced by TT3 which is a strictly power/weight class of 9.0:1 (or 9.5:1 with aero)

TT2 (formerly TTS) is 8:1 (no aero adjustment like TT3)
TT1 (formerly TTU) is 5.5:1
TTU is anything goes

Mikelly

Target HP is 450-490 at the wheels. I know that is reaching a bit, but that's what we're hoping for. Gets me in the TT1 Pwr/weight range for competition in my region.

Mike

drivinhard

iTrader: (1)

Anything over 456 or so would push from TT1 to TTU, so your best bet is to just cap your HP @ 450 or so, or ad some lead.

Otherwise, you end up 30 hp barely into "unlimited class" which is not what you want to do.

Mikelly

Well the reason I was shooting for more was that it would be easier to detune it with the XFi standalone than it would be to "find more power" without replacing internal and external parts.

Shooting for 450 Wheel HP is certainly cheaper to do. Seems like that extra 30-40 is very expensive.

Mike

95ONE

iTrader: (1)

LOL.. ok.. JUST released these rules. But so you can clearly see TT1 or TTU is your only choice, and TTU (according to new rules) is just not a class you want to be in if you're not a pro race team. So your best power to weight ratio stands as stated.

North of 450 gets very very expensive with exponentially Diminishing returns. Full burns style, custom headers-$2K+, Full Fast 102 Combo-$2K etc.(fuel rail and plumbing, Throttle body, porting, - ($2K Jesel Rockers, Titanium Valves, for a very high Revver...flat tappet style lifters and cams are quite expensive also.) We both know that extra money can make the car much faster by spending it on the chassis, tires, better safety, etc. But if you have the best of everything to make the chassis perform already, All the telemetry and datalogging instruments, and just want to de-tune, there certainly is no law against that. Remember though, most forged internals are MUCH HEAVIER than stock and are pointless if the stock bottom end can handle the power.

I love what you have and what you are doing. For the record though, you can always add more power above 450 easily without having to change out the internals. Ever. Don't let that hold you back. Otherwise I would START with an LS3 or larger for big power if you absolutely must have it.