I am considering building a v6 for road racing in order to reduce the weight.

Can a light weight v6 make enough power to compete against a heaver small block.

I have searched here and elsewhere. Not alot of information that I have found on the cababilities of any chevy v6 which will fit in our chassis. I understand that the 3.8 buick does not fit well.

Any help appreciated as to how these stack up against a small block.

What power would a v6 need to make to be comparable to a 500 hp smc?

 

according to the truck weigh station; my optionless V6 car is only 3xx LBS lighter then my optioned GTA. in case that influences your opinion at all.

 

N/A, the best I have seen is tad over 200 at the tires.

Boosted, I know it can make over 300, maybe 350 at the tires.

I would be more worried about the constant high RPMS. I know these blocks are rated high rpm, but I dont know anyone whos tested that for extended times.

 

FOr the amount of money you're going to spend on modifications to a V6, you're never going to make as much power as someone who put that same amount of money into their V8. $3000 on builing a 6-er won't get you much just because most everything is going to be expensive one-offs. But you can get a new set of heads aluminum heads for a SBC for under $1000. THen all the rest of the fun stuff. Now, if you plan to do most of the fabrication and machining yourself, you can save money, but then who do you grab by the ***** when a product fails under warranty or doesn't fit right or whatever. It's all about cost efficiency, if you're going to compete against people who are dumping the same amount fo money into their cars as you are, they'll win with a V8 a good majority of the time.

Now, please do not take this as a "go V8 or go home" post. I am currently in the planning stages of a 3.4L turbo install because I know it'll get me a good deal more power and will shutdown MSOT things ON THE STREET, but at a track, for competition against 8's, there's no way.

 

SDIF, It can be done no problem.
Problem with the answers here is no one here has the money or knowledge to build such a motor in thier garage. GM has proven multiple factory race motors naturally asperated over 300hp. Its the motor of choice they used in the "Stadium Truck" racing series as well as they use them in hydro boat racing for lightweight powerplants. Some of the boosted 2.6 to 2.8l60*V6 motors are putting out in excess of 600hp.

Ani't noone going to be doing anything on a stock shortblock though- thats all we've seen here for the most part (and no, oversize aftermarket pistons, and home ported heads aren't going to cut it. Expect to drop about $6000 for about 300-350 hp.

you will easily compete against a heavier nosed, poorer handling V8 putting out 400-450hp

I have about 135rwhp and an automatic and turn a 1:08 laptime on street tires on the same course the CMC cars ran about 1:58 times on 210rwhp, stickshift and racing tires. (NOTE: car weights were close to the same due to me being full weight creature comforts and them being stripped race weight.
Dean

 

I know of a GTP owner with a 550 horsepower Supercharged 3.8L. He has everything.. Heads, Cam, Headers, Intercooler, bigger blower and 15 psi.

 

A 3.8l 90*V6 is about 18.5" long and wider by far than a little 60*V6 that is narrow and 17" long. For refeence, a SBC V8 is about 22" long.

Also the supercharger accessories put weight back up on the nose of the motor over the front wheels so you might as well be even in handling between a boosted 90*V6 and a V8.

 

Thanks to everyone for the help.

I have never had any experience with a v6.

For now I will stick w the v8 since its paid for.
355 Zero deck height
11:1 with JE flat tops
195 AFR Heads angle milled and ported
6 in rods
Steel crank
Vic Jr
Holley 750
Solid Roller

Never seen the track yet (Never enough time w /work and family and other cars)

I would like to try a v6 some day as I think it coulb be very fast for a smooth driver on a tight technical track.

Dean, I remember you getting rid of some unsprung weight. What did you do to achiev this? And how much net weight did you remove?

I do not know how to get my car any lighter at this point. Glass Hood, Lexan, No Interior, Doors in name only, all brackets & non escential mounting points removed, No extra wiring (starter, fan, ignition & braklight only), All undercoating stripped, All e brake hardware and mounting point removed, All No dash, lightweight steering column, Full Cage with nascar type door bars.

Scaled dry w/o engine, trans and exhaust at 1,863lbs

Any idea what it will weigh with drive train and exhaust?

 

i am also interested in what you have done to reduce weight. i am currently trying to cut as much weight out of my 2.8 as i can without gutting the interior. so far i have removed about 50 LBS. but i don't know what else i can loose. i need heat, and i need seats. i pulled one of the rear seats, i pulled my smog pump, converted to a smaller coolant reservoir (mostly for looks, i only removed like 1/3rd of a pound in coolant :roll: ) pulled all my radio equipment, pulled my cruise control, am going to pull my hatch pulldown (only about 2LBS), pulled the vacuume reservoir and associated bracketry out of fender,.. i just can't think of what else. it's a street car, so i can't pull out the bumper core supports... i am thinking about a side dump exhaust, but am worried it would be louder.. this is my daily, and i like it quite (the 350 is loud enough for both of them).. i am out of stuff to yank...

 

carb'd LSx ftw, that alum. block should help your wieght issue

 

Xophertony, SDIF and I are talking about unsprung weight reduction for ride quality and handling ability, not overall weight reduction.
Quick lesson: "unsprung weight" is anything below the springs that will move with the wheels. "Sprung weight " is anything that is resting upon loading the suspension (Note that many supsension parts share both catagories since they link between both sprun and unsprung.) What you want is a high sprung to unsprung ratio like a 3:1 or higher.

What this means is for every 3 lbs you remove up top in sprung weight, you NEED to remove at least 1lb of unsprung weight to maintain superior handling charateristics. On a smooth track this is not as critical, but still will make a difference between a fast car and a real fast car in trasistions. The higher ratio car on a bumpy track will shine because every road imperfection will cause the lower ratio car to unsettle easier and slide lossing traction in corners, braking and acceleration.

Now my car is still probably close to factory ratio (whatever that may be)-I have never cared to weigh it- I judge things by seat of the pants feel whendriving it. You *** will tell you if you like it or not- most here complain of "harsh rides" when running Koni Yellows, I don't. What I do know is when I build a car I do it properly and "properly" costs big bucks.

Here lies everyones problems (including mine); When we modify a suspension of a factory car, that generally includes (this applies for a 3rd gen) having to purchase and install (often welded type installations) provissions to be able to tweak factory setting of a suspension for setups. These additions create more unsprung weight in the attempt to better the geometry for superior handling. In one way you are helping, in another you are hurting. the gains are generally better than the hurt so we all do it.

Now what I do is invest in high dollar exotic lightweight parts that counterbalance the hurtful unsprung weight addition. Parts like aluminum tierods, shaving spindles aluminum front hubs, removal of unnecessary parts like backing plates, lightweight lugnuts, lightweight shocks and struts if obtainable(what out running aluminum shocks on the street though- they do not last long, race cars don't see the milage), lightweight brake setups (my fronts being 13"/6pot are 4lb's lighter EACH side than the factory 10.5"/1pot setups), moser drilled axles, carbonfiber ACPT driveshaft(Don't buy the BMR semiCF shaft- they are only wrapped in CF) Chromemoly and/or aluminum suspension links like LCA's & panhard, lightweight racing pinion gear sets, 16"X8"wheels(which are much lighter than most aftrmarket 17's and 18's. If you race then I would suggest CCW 's at about 17lbs each rather than my 21lb irocs).

Now other than my wheels, I have invested in the unsprung suspension parts that are also lightweight rotation mass for less drivetrain power loss- those are the most important to focus on first.

The only part I decided not to skimp on is the torquearm because this car sees daily street abuse and I wanted the heavyduty made Spohn setup that I know will never give me problems- My driveshaft at 4 lbs counteracts the heavy addition of this TQarm over the factory one.

yet, they will ban me for all this helpful info because I cussed out one of THEM in years past. If they had a clue, they'd realize to only delete hurtful posts-THATS THE DEFINITION OF MODERATE. yet I still come right back and this iritation grows.

 

Look around for the post. There is a detuned 2.5 60* engine used in open wheel dirt track 700+ HP. Someone here bought a display version for the fancy intake system.

--------
In F1 they said the turbo would never last and first attempts got 1500hp out of a 1.5 V6.

Anything can be done with money. You can be different or go cookie cutter.

 

I was going to buy it, but never did. That motor never put out 700HP. It was a factory prototype race motor that GM built and Ryan Falconer did the intake and fuel injection with a Motec computer. the engine dyno'd closse to 400hp back in the late 80's. This is a picture of it after it was scrapped and reassembled as a dummy motor (no internals and not original heads either)and used as a display in the lobby of GM's corporate office for several years. Thios is it photographed for the cover of the GM Power Manual.

 

Drop in a 4.3 Vortec. They are easy to get 300-350 FWHP out of and still be streetable. Then put a T-56 behind it.

 

Any info on how to build one up to that level.

4.3 vortec that is?

 

Does this car have to be federal or smog compliant in any way or is it going to be a full time racecar?

If so then I would opt for an aluminum Buick V6 if going to a larger V6.

HOWEVER, If you want to keep in lines of a true 3rdgen small powerplant you can find a somewhat useless Iron Duke block and o from there. I A little hidden secret I decovered awhile back about the compatability of them to Pontiac Super Duty Four racing componants. They are basically half a V8 and share the right bank componants for the most part other than crankshaft and camshaft.

Machinist Notes

 

"Smog Laws: We Don't need no stinking smog laws"

Race car only. Running American Iron. Rules state no min weight for v6 car.

 

Similar to this, but with ported Vortec 4.3 heads instead.

Hot Rod Magazine builds a Chevy V6 Engine

 

But they are most likely requiring a 60*V6 since the only 90* V6 that ever came factory is a TTA and they most likely I'll assume not allow boost. The 3.8 and 4.3's are 90* V6's and were never a N/A factory option.

I would be curious to see the actual rules- these are just my assumptions.

 

But they are most likely requiring a 60*V6 since the only 90* V6 that ever came factory is a TTA and they most likely I'll assume not allow boost. The 3.8 and 4.3's are 90* V6's and were never a N/A factory option.

I would be curious to see the actual rules- these are just my assumptions.

Rules are located at Welcome to NASAProRacing.com!

...from my iterpretation any GM engine can be used forward or backdated. Blowers and turbos are allowed, but no Nitrous.

 

Well the AJE tublar crossmember and arms lightened my load by 50-75lbs.... went to a coilover set in the front as well. Then relocated the battery to the back...

How everything will hold up... we will see!

 

a gtp 3.8L can make over 680hp to the wheels.

mine runs mid 13's