BB70Chevelle

About as far as I can go with my mustang chassis (25.5 sn95 trz rear suspension team z front suspension) without having the motor and transmission and very interested in the new ultra street class that's being run at cecil next year so trying to plan out an engine build for this winter but not sure where to start. For a turbo car your allowed a maximum of 440 cubic inch using 15* degree heads only with either a 76 or 80mm cast wheel turbo at 3200lbs for a 76 or 3250 for an 80mm on a michey thompson 275. In order to be competitive car needs to run in the 5.30's-5.40's range. With those goal/restrictions would you build a 5.3 or 6.0 based motor? Would keeping it under 350 cubic inch be better suited for that size turbo? What compression should the motor be at? With the cylinder head restriction is a L92 headed motor the way to go? Will a stock casting hold the power needed to run those times consistintly?

Here is the complete class rules,
1/8th mile Eliminator

BODY:
Fiberglass/Carbon body panels are limited to hood, rear deck lid, fenders, doors, and bumpers. Cowl hoods may not be taller than half way point of the windshield. Forward facing scoops are prohibited on power adder combos unless factory installed or less than 5 inches from flat area of hood. Inlets for turbos and superchargers must not be exposed to ram air

INTERIOR:
Aftermarket steering columns are allowed. Factory type dash accepted. Must have carpet.

ELECTRICAL:
Optical devices are prohibited. All entries must have operational head lights and tail lights.

ENGINE:
Aftermarket blocks and cylinder heads are allowed. All entries must utilize a single carburetor cast intake manifold. Motor plates and solid mounts are allowed. Engine must be in stock location. Mufflers are required on all vehicles (except turbos). All SB power adder engines are limited to 440 cubic inches. SB N/A limited to 470 and BB N/A limited to 632 and BOP power adder limited to 588. Any engine in question will be measured with a P&G gauge. A correction factor of 1.5% will be used. Competitors may be asked to remove a cylinder head for bore and stroke measurements should any discrepancies arise.

INDUCTION:
Small blocks and BB N/A combinations may use a single cast intake manifold with single carb or EFI. Cast tunnel ram permitted on stock valve angle only w/ weight penalty. (See* below) Small Block N/A may use cast tunnel ram/sheetmetal/dual carbs w/weight penalty (See*below)

POWER ADDERS:
Nitrous limited to SB and BOP entries - Progressive nitrous controllers are allowed. Entries must utilize a single stage nitrous plate with one nitrous, one fuel and one redundant purge solenoid. Foggers must be disconnected and all solenoids must be capped off. Nitrous plates using fogger nozzles are not allowed. Jet limit/solenoid size TBD on stock valve angle with cast tunnel ram & nitrous.

Turbo and supercharged entries are limited to stock valve angle SB combos only. (SB CHEVY 23 DEGREE - SB FORD 20 DEGREE – 18 DEGREE MOPAR - FACTORY HEADED SMALL BLOCK FORD MOD MOTOR - LS CHEVY 15 DEGREE)

TRANSMISSION:
Any OEM style automatic or OEM manual transmission is allowed with power adder. Clutch assisted/clutchless manual transmission allowed on N/A. Manual transmissions must utilize SFI approved bell housing.

REAR SUSPENSION:
Stock type rear suspension or ladder bar only. Coil over shocks are allowed. Anti-roll allowed. Aftermarket replacement control arms are allowed. Stock frame rails must be in place, notching permitted. (N/A cars/trucks permitted ladder bar suspension without weight penalty)

FRONT SUSPENSION:
Factory type front suspension only. Coil over shocks are allowed. Aftermarket replacement control arms are allowed. Aftermarket K-Members allowed.

WHEELS/TIRES:
A maximum of a 28 x 10.5 non W slick, 28 x 12.50 ET Street or any 275 radial may be used on N/A, power adders limited to a P275/60-15 MickeyThompson Tire P/N 3754R radial tire. Wheel width is limited to 12"

NITROUS WEIGHTS:
Base weight includes BOP combos - 3200
All heads 14.9 and under - 3250
Any canted valve head - 3250
All heads 15 degrees and above carry no additional weight
Any 23 degree combo - 3000
Blue Thunder Cylinder Heads - 3300
Any 20 degree ford – 3000
TFS-R ford - 3100

SUPERCHARGER WEIGHTS:
F1A-3200
F1C - 3250
YSI – 3250

TURBO WEIGHTS:
T-76 - 3150
T-80 - 3200

N/A WEIGHTS:
N/A Inline head – 2600
N/A Non-Inline head – 2700
N/A (big block with standard deck height and conventional head) 2900 lbs
N/A (big block with tall deck height and conventional head) 2950 lbs
N/A (big block with standard height and big chief head) 3000 lbs
N/A (big block with tall deck height and big chief head) 3100 lbs

GENERAL:
No Billet cylinder heads/blocks
No Billet wheels on turbo combo
No Reducers on turbo or supercharged combo
Alcohol/E85 legal (meth injection legal on non-intercooled combo only)
All turbos and superchargers must be as manufactured from factory
No muffler required on turbo entry, required on all other combos
No bull horns
Gear driven supercharger allowed
Belt driven supercharger deduct 50 lbs
LS 15* add 50 lbs
Non Intercooled boosted combos deduct 50 lbs (no deduct if on Alcohol for fuel)
Leaf springs deduct 100lbs
Ladder bar add 50 lbs (except N/A)
*Cast Tunnel Ram with 4150 carbs on stock valve angle head on SB NOS add 100 lbs
*Cast Tunnel Ram/Sheetmetal/Dual Carbs on SB N/A add 50 lbs
Single 4150 carb/throttle body deduct 50lbs
V6 entries deduct 150lb

kmracer

iTrader: (1)

what do you mean by cyl head restriction?

what fuel do you want to run?

also, are you on yellowbullet?

BB70Chevelle

Restriction being your allowed a 15* head only which from what ive seen the majority of after market casting ls heads are not 15*. (rhs and afr being the only two 15* castings ive seen so far)

Car will be run on race gas.

Yes, I'm a member on yellowbullet also.

BB70Chevelle

Few pics of the chassis the motor will be going into,

BB70Chevelle

Talked with Phil (95mmrenagade) and came up with a plan for the motor,

Iron 5.3L block bored to 3.905
Stock crank
Compstar 6.125 H-beam rods
Custom diamond pistons to get to 11.5:1 compression
ARP head/main studs with dowl pinned mains
AFR 205cc heads
Victor jr intake
Marcella intake elbow
Wilson v-band t-body

BB70Chevelle

Starting to gather the parts for the short block and have a question. To run this class I need to make around 1000-1100hp and I know the stock crank has been proven to handle this power but can it reliable handle that much power for an entire racing season? Would it be better to go with a callies compstar 3.625 stroke crank insted?

thirdgen60

iTrader: (10)

IMO you might want to go after market. Plenty of people run the cranks to that power but the reliability is very questionable. Might as well bust out the coin now for the peace of mind, nothing worse than having a broken motor in the middle of the season.

JAX04

iTrader: (17)

I agree with the above post. Also, just wanted to say, liking the project man!

Keep it up!

BB70Chevelle

Thanks and I agree i'd rather go after market and know its can take it then have to worry about it failing on me after spending so much time and money on this project. Ended up picking up a complete 6.0L motor, intake to oil pan and only paid $400 for it so going to see how well i can make this option work with that size turbo and a 370" Would the compstar be a good crank for the intended power?

thirdgen60

iTrader: (10)

I would check with one of the vendors on the site about a complete rotating assembly. They would be able to set you up with something for your power level. Texas speed and virginia speed are a couple of good ones.

99f1

iTrader: (6)

Garret gt42rr turbos are a great turbo and a bit cheaper since the 43rr came out. (didnt read if you already have a turbo) i feel if you have proper oil flowing you can get by with a cheaper crank.to me a callies crank is one of the best. The oil valley should be opened up for better flow(the one on the block itself..read it on gm hp magazine in 05). I did it with my 408ci tt set up. As well as haveing your heads,pistons,and turbos swaitech coated.all hotparts. Will help immensly. A 50 shot sprayed on the intercooling system is pretty cool too.if you choose to get an aftermarket crank and save the loot with one thats not so pricey.you should buy billet main caps. Have a good 1

MelScrilla

iTrader: (2)

Can't wait to see how this project turns out, I think ultra will be a great class for guys on a "budget" ever since x275 became so popular.

lazaris

iTrader: (5)

I believe ALL Pro makes a 15* cathedral port head as well.

BB70Chevelle

After a long winter of not much getting done and almost selling the car I'm finally back to work on it. Last weekend I painted up the cage in por15 and top coated it in black hammertone. Came out pretty good but, Needs a second coat and Hell with messing with trying to brush it on I'm just going to have a friend come spray it on. Also pulled all the front suspension out to start on the body work in the engine compartment. Found some rust in the strut towers so ended up having to cut them apart and this week will work on replacing the metal.

Lsx swap k-member should be here next week from team z, Then 6.0L motor can go in. Picked up a s475 turbo today, so can begin figuring out how I want to route everything. Will be using truck manifolds with v band clamps, with a 2.5" stainless crossover pipe with twin precision 46mm wastegates. Turbo setup will be non-intercooled with meth injection putting my weight for the class at 3100lbs.

Plan for the motor is to do the build listed above but to start will be using patriot ported heads for budget reasons and will be using a 4150 series throttle body instead of the intake elbow to use the 50lb weight break listed in the rules.

Will post updated pics this weekend once I'm done media blasting the frame and strut towers.

bigti99a

iTrader: (16)

i think boost will treat you better than the N20 you where thinking. would you be able to run a little huff on N20 and also have a turbo in this class?

BB70Chevelle

No can't use both in this class, but turbo was what i originally planned for the car so need to stick with it otherwise I'm sure at some point I would have wanted to change later on.

WheelsUp84z

iTrader: (14)

we have a class just like that down in NC that i'm building my car for. Its limited to 76mm cast wheel only turbos though. Class record is 5.39 with its a 421 sbc on e85/box stock s400. Thats at I think 3250's. There is also a stock ci/heads/cams 4v mod motor car with the same turbo thats in the 5.50's. So realisitically you can run just about any sized motor and make it work. I think a 370 with the s480 would be a really hard combo to beat.



Looking over the rules some more, You'd be crazy if you think 5.3's will be top of the pack. With ysi/F1c's and 440 ci on tap that's asking for 4 second slips.

BB70Chevelle

I know it wont be, I've seen cars in this class last yr run 5.1-5.2's in x275 but having no prior experience or knewledge with turbos if i can get in the 5.30's I'd be happy and would be a good starting point to build from. Trying to do this on a budget and coming out running 4.9's won't happen but if i can come out and be competitive and have fun while going threw the learning then that's fine with me.

BB70Chevelle

Does anyone know if twin precision 39mm wastegates will be ok for what im doing, or should i opt for 46mm gates?

1fast bird

iTrader: (22)

That is what I was gonna use with my single GT91. It's all how you have the wastegates plumbed in relationship to flow. Try to at least get a 45* angle off the crossover or straight off an elbow....... Hard to explain without a diagram, but the more the exhaust is directed into the gate the better. Having them at 90* to the flow is less than optimal........ To answer your question, yes 39's should work.