Endurance + boost
 

Building my BRZ into an endurance car and looking for opinions on safest way to add boost and still offer reliability. Want to keep the FA20, and ideally not change internals. Not looking for gobs of power, but just a little extra kick for the car. Won’t be going wide-body or anything like that.

Anyone endurance racing their 86?

I think the usual endurance best practices apply. 1)Keep it well oiled. 2) Keep it cool. 3)Keep the RPM's low.

Figure out what you need to accomplish those on the 86 platform and you should be good.

What kind of endurance racing, and at what power level?

I don't know anyone racing enduros with forced induction. What series and class? A friend of mine campaigns these cars in WRL.

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Endurance racing with forced induction is definitely a pursuit of the well funded.

Yeah I don't mean to be a naysayer but this is going to be a very difficult endeavor

I only knew of one boosted car doing endurance racing and they want back to naturally aspirated after being plagued by issues.

Well thats disappointing to hear. We had been running an NA miata for awhile, then up to an e30 with an M52 swap, and I was hoping to use the BRZ as a next step. Thinking light boost would help make it a reasonable upgrade from the e30, but sounds like it would need to stay NA or go for a swap.

I would make sure you have everything good in NA form before throwing boost at it.

I would think you would want to see what class you would be in boosted, what the competition is and what else needs to be done to be competitive in the class. Usually boosting is considered a higher end addition after everything thing else has been done.

That being said I think with good cooling for water and oil you could run the Edelbrock SC at low boost safely enough. I know there are people that say I know so and so and they blew up. But what else did they have honing on? NA can blow up too. A company that big is going to provide the car warranty (new car pro installation) thinking they would have to pay for an engine.

Car has been a garage/track car for a few years now. Shes pretty well sorted out at this point.




Kind of the path im thinking. Low boost and stay on top of cooling and see how she does.



No concerns about classing. Car will be built for AER and WRL, AER does qualifying to determine class and WRL use power/weight ratio.

If there's not a specific reason play in that power:weight bracket - I've done enough racing (and endurance racing) over the last 17 years to advise you to try and be competitive in a bracket where you can remain NA. But if you're committed then my only input is to account for these realities:

The development cost curve goes up exponentially with every "allowance" a rule set offers and forced induction is major allowance meaning the cost to be competitive adds several zeros to the expense budget. And all that's AFTER you spend the $$$$ to address the added entropy FI introduces.

You are accelerating a mass faster = more fuel costs (plus you can't run as lean = more fuel costs) ​
You are converting more momentum into heat through friction = more consumable costs (brakes, bearings, tires, ball joints).
You are generating more heat in the engine bay, the transmission and the differential - so you will have to add weight (and cost) to cool it - Oil cooling, trans cooling and definitely diff cooling - and that weight - goes back to the first point.

My concern for you is that this will be more of an engineering endeavor vs a racing endeavor and vast majority of your money will be spent away from the racetrack.

I agree completely with the above, you're talking about a lot of engineering besides the engine. But if this is what you really want I'd think about something like this:

Turbo set up for easier boost changes or get a couple pulley sets for a mechanical blower. Roughly speaking I'd want to add a max of 50% more power, which translates nicely to 7 or 8 psi of boost. That means 50% more cooling system and oil cooling, plus an intercooler. E85 would be a plus. Start off with perhaps 5 psi of boost so things don't get out of hand too quickly while you're sorting the rest.

For power, yes. For endurance racing I would think MPGs matters more. The fuel burn rate of E85 is much too high and therefore you either have to run a larger fuel cell and more fuel weight which could lead to longer stops because more fuel has to be put in (depending on how you fill). Being able to run the maximum stint time with the least fuel on board is ideal. E85 is the enemy of fuel economy.