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-   -   Lifespan of a Tracked 13 BREW (https://www.rx7club.com/race-car-tech-103/lifespan-tracked-13-brew-1139920/)

TomU 10-27-19 11:01 AM

Lifespan of a Tracked 13 BREW
 
For those that have dedicated track cars, about how many hours of pure track time (road course) can you go before needing a rebuild? Yes, it's dependent on a bunch of factors, but i'm talking on average

LargeOrangeFont 10-27-19 06:47 PM

I have about 7000 track miles on my LS1 swapped car. Every turbo rotary guy says they would be 2-3 engines in by now :)

Viper GTSR 10-28-19 11:48 AM


Originally Posted by LargeOrangeFont (Post 12378243)
I have about 7000 track miles on my LS1 swapped car. Every turbo rotary guy says they would be 2-3 engines in by now :)

Chances are those "turbo rotary guys" didn't have their motors built & setup correctly.. ;)

racingdriver 10-28-19 12:27 PM

60 hours . I have roadraced rotaries since 1997.

LargeOrangeFont 10-28-19 12:28 PM


Originally Posted by Viper GTSR (Post 12378346)
Chances are those "turbo rotary guys" didn't have their motors built & setup correctly.. ;)

They did, and pretty much said said they got around 40-60 hours out of them if something didn't catastrophically fail.

NA it will last way longer.

racingdriver 10-28-19 12:30 PM

That would be with a turbo engine and an 8000 rpm redline. No turbo it would last longer as with a turbo the apex seals chatter and wear the housings .When you wear 30 % of your apex seals gets really bad quick.

Smokey The Talon 10-28-19 03:48 PM

RacingDriver has all the data you need for fully raced motors.

On my HPDE car I'm around 9k-10k miles over the past 9-ish years. Compression was mid-high 90s last time I tested. Still hot starts and cold starts fine.

dguy 10-28-19 03:56 PM

I rebuild every 20 hours on boost. Never needs anything other than soft seals, though this is with ceramics.

mikey D 10-28-19 07:14 PM

Interesting thread.

How many hours are people getting on na 13 pp engines, 9k redline? I understand they wear faster when you push up to 10k?
How about stock seals in a non pp kept below 8k?

Im building a new toy and have been trying to decide between lsx, 13b pp, or na 20b big street or bridge port. The how often do I rebuild has been on my mind.

Just some anecdotal stuff, Kyle Mohan completed an entire season of formula drift without tearing his 1000hp nitrous spooled turbo engine apart. They run those engines hard, even if it's for short stints.

BLUE TII 10-28-19 10:54 PM

60hrs eh?

So long as you average 100mph on the track you will get about 6,000 track miles?

Pack up that premix boys, were going to Daytona- whooooha!

:goodrebuild:

LargeOrangeFont 10-29-19 12:26 PM


Originally Posted by mikey D (Post 12378402)
Interesting thread.

How many hours are people getting on na 13 pp engines, 9k redline? I understand they wear faster when you push up to 10k?
How about stock seals in a non pp kept below 8k?

Im building a new toy and have been trying to decide between lsx, 13b pp, or na 20b big street or bridge port. The how often do I rebuild has been on my mind.

Just some anecdotal stuff, Kyle Mohan completed an entire season of formula drift without tearing his 1000hp nitrous spooled turbo engine apart. They run those engines hard, even if it's for short stints.

Short stints are the key there.. running it hard for a minute is very different than running on a road course for 20-30 minutes. To your question - the LSX is going to be easier to keep cool, more forgiving, cheaper on fuel, and cheap to build. You can get a pullout or a crate engine and make 500+ HP with a cam swap or buy the 376 525HP crate LS3. I'm not saying one is better than the other here, but by and large one is CHEAPER in the long run.

mikey D 10-29-19 01:41 PM

I agree. Also one of those options has a huge and cheap aftermarket and replacement parts supply chain.

Remove sentiment from the equation and its a no brainer.

TomU 10-29-19 04:08 PM


Originally Posted by LargeOrangeFont (Post 12378243)
I have about 7000 track miles on my LS1 swapped car. Every turbo rotary guy says they would be 2-3 engines in by now :)

You may as well be driving a vette lol :ugh2:


Originally Posted by dguy (Post 12378385)
I rebuild every 20 hours on boost. Never needs anything other than soft seals, though this is with ceramics.

Well, that's certainly depressing. I'm at about 25 and think my compression is starting to wain :(

LargeOrangeFont 10-29-19 05:20 PM


Originally Posted by TomU (Post 12378570)
You may as well be driving a vette lol :ugh2:

It is 400lbs lighter than a comparable vette. That said, if I was building a track car today, there is no better platform for the buck than a C5 vette.

racingdriver 10-29-19 09:43 PM

We pulled apart the last engine this year ( 20b turbo, 16 psi) at about 20 hours and it looked mint. Pre mix is important as is running the right ignition timing . A lot of guys run too conservative and that creates engine damaging heat. Mazda competition mentions engine wear is exponential over 8500 rpm, especially bearings and seals.

A very close friend of mine runs almost the same spec fd with a 7 litre ls7. He's on his 3rd engine since 2010 due to tired rod bolts, tired cam springs, and the last time bad luck when the external oil pump belt came off. In racing anything can happen.

Our 20 hour engine blew an apex seal when the wastegate failed out of the blue with no warning and overboosted before the limited kicked in. It was 10 years old so I should have changed it I guess.

The 500 hp v8 compared to a 500 hp 13b turbo will be cheaper to run , better on cheap pump fuel, easier on rear tires, has torque out of the corners and in traffic, AND easier to drive, especially in the rain .

Comparing the 700 hp v8 to a 700 hp 20b turbo you'd need a fully built , big cam, hi revving LS from somone like K tech to compete. That would become a high maintenance engine and not cheap to the point that cost would be similar. Drivabilty goes away too. I love the 20b turbo as I can dial in more or less power to suit the track, cant overrev it due to a missed shift, and on low boost with the 20b torque is actually pretty good in the wet.

Wouter

racingdriver 10-29-19 09:49 PM


Plus it just sounds amazing !

LargeOrangeFont 10-29-19 09:58 PM


Originally Posted by racingdriver (Post 12378620)
We pulled apart the last engine this year ( 20b turbo, 16 psi) at about 20 hours and it looked mint. Pre mix is important as is running the right ignition timing . A lot of guys run too conservative and that creates engine damaging heat. Mazda competition mentions engine wear is exponential over 8500 rpm, especially bearings and seals.

A very close friend of mine runs almost the same spec fd with a 7 litre ls7. He's on his 3rd engine since 2010 due to tired rod bolts, tired cam springs, and the last time bad luck when the external oil pump belt came off. In racing anything can happen.

Our 20 hour engine blew an apex seal when the wastegate failed out of the blue with no warning and overboosted before the limited kicked in. It was 10 years old so I should have changed it I guess.

The 500 hp v8 compared to a 500 hp 13b turbo will be cheaper to run , better on cheap pump fuel, easier on rear tires, has torque out of the corners and in traffic, AND easier to drive, especially in the rain .

Comparing the 700 hp v8 to a 700 hp 20b turbo you'd need a fully built , big cam, hi revving LS from somone like K tech to compete. That would become a high maintenance engine and not cheap to the point that cost would be similar. Drivabilty goes away too. I love the 20b turbo as I can dial in more or less power to suit the track, cant overrev it due to a missed shift, and on low boost with the 20b torque is actually pretty good in the wet.

Wouter

Spot on.

Viper GTSR 10-30-19 08:09 AM


Originally Posted by racingdriver (Post 12378620)
The 500 hp v8 compared to a 500 hp 13b turbo will be cheaper to run , better on cheap pump fuel, easier on rear tires, has torque out of the corners and in traffic.

Wouter

Altough many EFF8374 setups ive followed in road racing are extremely competitive (usually the top of their class or outright 1st place) with no issues on power out of corners with near instantaneous throttle response and same motor for many seasons... 🤷🏻*♂️ So I guess there's too many variables than to just say lsx > 13b for road racing given the build/setup is so much more important for the rotary.

cloud9 10-30-19 10:37 AM

There will be track layouts that naturally favor one vs the other, as well.

racingdriver 10-30-19 11:23 AM


I agree the new turbos for the 13b are amazing and will be competitive. And there are many factors to make one work better than the other. A close ratio gearset would help a lot. In this race the LS has the edge over the 13b.


Red rx7 has a ls7, silver rx7 20b turbo. The pastel blue rx7 has a 13b turbo. All cars were driven by experienced drivers and running slicks. The 13b is this instance was not as quick as the ls7, especilally in traffic.

Viper GTSR 10-30-19 02:38 PM


Originally Posted by racingdriver (Post 12378730)
https://www.youtube.com/watch?v=lk-IWfS0wVI

I agree the new turbos for the 13b are amazing and will be competitive. And there are many factors to make one work better than the other. A close ratio gearset would help a lot. In this race the LS has the edge over the 13b.


Red rx7 has a ls7, silver rx7 20b turbo. The pastel blue rx7 has a 13b turbo. All cars were driven by experienced drivers and running slicks. The 13b is this instance was not as quick as the ls7, especilally in traffic.

Omg this was an AWESOME video!! Great to see our FD's still fighting it out in racing series's like that... this race was 2010? Do they still have this series or series's like this where FD's compete!? 🏁 :) I see a lot of modern sports cars and exotics mixed with older ones too in this. And that chevy was a tube framed stock car vs REAL street car chassis'd FD tearing its ass in this race lol... awesome stuff man.. :D 👍

BLUE TII 10-30-19 03:50 PM

Well in actual racing there are rules...

So, how is the turbo rotary classed against the LS V8s?
EFR rotary loses its torque at the wheels advantage over the LS V8 around the 6 liter displacement range or over 4th gear 1:1 gear ratios (ovet ~ 140mph).

TomU 10-30-19 04:17 PM


Originally Posted by BLUE TII (Post 12378780)
Well in actual racing there are rules...

So, how is the turbo rotary classed against the LS V8s?
EFR rotary loses its torque at the wheels advantage over the LS V8 around the 6 liter displacement range or over 4th gear 1:1 gear ratios (ovet ~ 140mph).

Well, think this thread has officially gone off the rails. Think i got my answer, but more data points would be useful

Now back to the Rotary vs V8 discussion.... :biggrin:

And FWIW, there's no competition between a Rotary and V8. I'd rather give a point by to a V-8 than drive one :icon_tup:

billyboy 10-30-19 09:54 PM


Originally Posted by BLUE TII
So, how is the turbo rotary classed against the LS V8s?



Over here at least, anyone serious would laugh at the prospect of an LS, except for production classes....racing iron blocks were made for a reason they say.

Rules here are 1.8 times displacement for rotary plus a further 1.7 for turbo, except the one where the 20Bs are deemed eligible - and they end up with a 1.75 multiplier to keep under a 6 litre maximum displacement rule.

Truthfully, I'd be surprised if many good v8s would lose out to any rotary out of corners or off the start line, short of burning it all up in wheelspin, no matter the turbo.

j9fd3s 10-31-19 11:27 AM


Originally Posted by TomU (Post 12378790)
Well, think this thread has officially gone off the rails. Think i got my answer, but more data points would be useful

it is, there are a LOT of factors that matter, the driver, the track, length of the races, etc etc

just to give one example, we used to race an Acura Integra, and we did sprint races, and the 25 Hours of Thunderhill.

in the sprint races the car would go about 2-3 seasons before needing any real work, but in the 25, we usually blew it up about half way through, and we had wheels falling off because the bearings (which were new and repacked with fancy grease), or in other words the duct tape at the end of the race was literally holding the car together....

actually example 2 is a Miata, and we took it to Nasa's west coast nationals, i forget the schedule, but we started practice Thursday with a 40 minute race on Sunday. out of the whole ~30 car field, 3 days of practice and qualifying meant that during the 40 minute race, something like half the field broke.

if you look, you'll see them on the side


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