turbo engine in an endurance race

[Rocketolds]

I have a couple of questions, I am thinking of a build a 3.8 or 4.1 twin turbo engine to run in one of the Silver State Challenge races. I plan on using two stock 86/87 turbos and I will be making my own stainless steel headers. I should only need 400-500 hp. I plan on running the 150mph class, which means I need this engine to survive at 5600 rpm for about 40 minutes with out blowing up. Anyone have any suggestions.

Thanks

 

[gnx7]

I would love to see you do this.... but I'm pretty sure it wouldn't hold up at those intended RPM's. These are low revving engines that in stock form don't make much power past 5200-5400rpm and have cast crank/rods. Also 99% of the people here drag race them and they only see 5000rpm+ for a brief moment.

If you chould change the final gear in the rear end and transmission to make the RPM's lower it would help out.

What transmission do you plan to run and in what car do you plan to put the engine into?

I wouldn't go to the effort of making custom headers and hanging two small turbos off the end. Aside from the fabrication challenge you would be adding more weight than a stock single turbo setup with the extra hairdryer and associated piping/brackets/downpipes. A small TE-44 turbo will meet/exceed your goals. A stock GN turbo will make about 350hp+ with 20-21psi, race gas, and high timing....

In spring I'll be running 3:07's in conjunction with a TH200-4R. I used a calculator and at 4200rpm with a 25" tall tire I should be able to go 151mph in OD (.67) with zero slippage (TC locked up). With a 26" tire and 5225rpms it says the magic 200mph number.

My cars aerodynamic rating is .29cd which is pretty slippery.

-GNX7

 

[Rocketolds]

GNX7

Thanks for the reply

The car is a 72 skylark, with 2.56 gears and 4 speed super T10 and 25 in tall tires, Spindle upgrade on front and nascar truck arm rear suspension

Car will also see occasional street driving and road courses and possibly real street elimantor

I was going to use twins just because I thought it would be cool.

I am not worried about the fabrication of the headers, I have plenty of room in the engine bay on the skylark and I have a plan which will make them very easy to make

At 150mph I will be turning 5140 rpm's and at 165mph I will be turning 5654 rpm's.

The cooling system has already been upgraded and I am planning on an extra large engine oil cooler

The other option is to use the 350 with fuel injection and turbos, but that generates other problems with poor intakes and possible head gasket issues

 

[Lee_Burough]

I'd recommend you purchase a double portion of gravity....To keep it on the ground and in control

 

[INTMD8]

IMO, a 500rwhp buick turbo V-6 with a 4-speed and 2.56 gears would have horrible response for drag racing or road racing.

I'm sure once you got going it would be useful for top-end work, but I couldn't imagine trying to launch something like that at the dragstrip.

 

[Rocketolds]

intmd8

I would agree but first gear in the trans is 3.42, so it should accelerate very well, this project will only see the drag strip if I go to the RSE event

lburou

That is why the chassis and suspension are being modified, and the car will ride about 2 inches lower than stock. A front air dam is also being installed, and the body will be shaved.

With the 3.8 I am hoping to get close to a 50/50 weight distribution.

My main concern is whether the 3.8 can take 5600 rpm for 40 minutes

Thanks for your opinions

 

[KendallF]

Originally posted by Rocketolds
intmd8

I would agree but first gear in the trans is 3.42, so it should accelerate very well, this project will only see the drag strip if I go to the RSE event

lburou

That is why the chassis and suspension are being modified, and the car will ride about 2 inches lower than stock. A front air dam is also being installed, and the body will be shaved.

With the 3.8 I am hoping to get close to a 50/50 weight distribution.

My main concern is whether the 3.8 can take 5600 rpm for 40 minutes

Thanks for your opinions

First let me say, what a cool idea! As to the 3.8 taking 5600 RPM, I don't think it can, with a stock crank. You might consider trying to gear the rear end higher to lower the RPM range. Making torque enough to pull the gear is not usually a problem.

If I were building this car, I'd build the motor "Supra style", sort of..by that I mean with no concern for turbo spool. Big turbo (say, a 70 with a big A/R turbine housing like an .82), moderate cam, and the biggest oil cooler and radiator you can fit. Gear it to turn a max of 5k RPM or so, and it should howl!

I have some weirder ideas involving de-stroker motors, but I will stop here for now.

 

[norbs]

If the motor is cammed correctly it will rev to 6500-7000 rpm no problem, with stock internals, ive been doing 4 years now so i don't see a problem if its balanced right.

 

[Rocketolds]

Thanks to everyone for the input.

ILBCNU6

A rear spoiler is also planned, I have not deceided what I am putting on yet.

Norbs
What kind of cam are you running?

 

[GS_Beavis]

Seems to me, for the kind of power you want to make, the RPM range you're looking for, cost effectiveness, and ease of installation a mildly built Buick 455 will do exactly what you're looking for. A 455 with a decent cam and a good set of heads will put out close to 500 horse with no trouble. All this with no overheating issues, good parts availability, an easy install in your Skylark, and you'll need BB torque to push that brick through the air... . And keep in mind, a BBB only weighs 60 lbs more than a SBC, so by the time you add headers, an aluminum intake, and maybe some aluminum heads, the 455 is not all that heavy. Just .02 from a guy that has both..........

 

[NoNos38]

Originally posted by GS_Beavis
Seems to me, for the kind of power you want to make, the RPM range you're looking for, cost effectiveness, and ease of installation a mildly built Buick 455 will do exactly what you're looking for. A 455 with a decent cam and a good set of heads will put out close to 500 horse with no trouble. All this with no overheating issues, good parts availability, an easy install in your Skylark, and you'll need BB torque to push that brick through the air... . And keep in mind, a BBB only weighs 60 lbs more than a SBC, so by the time you add headers, an aluminum intake, and maybe some aluminum heads, the 455 is not all that heavy. Just .02 from a guy that has both..........

Ya, your probley right.. , But whats the fun in that.. This would be something that has never, or very few times been done... Sounds really cool..

P.S. I think Norbs has been hitting the bottle alittle early today.. 7000 rpm.....

 

[norbs]

I only drink hot chocolate , but i may have to start on the alky soon. The cam is in my signature it s 224 roller from precision. I know these engines don't like big cams,and people have gone 9's with almost stock cams. However, if the cylinder heads can flow the extra airflow, a large cam is not going to reduce horsepower. Stage engines run well into 7500-8000 rpm to produce gobs of power. Basically whats the difference is the cyl heads. A stock block with GN'1 or M@A can rpm the same as any stage block, provided you add a girdle , better rods, and better crank. I don't use stock rods, but yes the stock crank will live at 7000 rpm. The buick power manual even suggests the stock crank can be used at 7500 for drag race use.

 

[salvageV6]

Get yourself a N/A Busch series V6 motor and run it.

Stage II and 500 hp.