N/A power output potential as race setup?

[Turdinator]

Originally Posted by diss7

It's hard for me to thoroughly comment as not all specs are known. But it does seem heavy.

My 86 (Base 86 in NZ) was 1198kg with a quarter tank of gas, so 1180kg. I've then taken out 20kg of interior, swapped a 20kg seat for a 5kg Bride, and have a track pipe, swapped the front brakes for Wilwoods, and use se37k's on the track, (which are basically the same as the stock 16" enkeis) So I'm confident I'm below 1150kg. Taking the rest of the interior out, (remember the other 20kg seat is still in there) Replace battery, flywheel, remove crash beams, window washer bottle, and you're under 1100kgs in my eyes.

I think there is too much focus with these cars that bigger is better. For example, why run 17's or 18's on a track car. Why not 16's? Because of the brakes. Well, there are plenty of cars at the race track that weigh around 1000kg running 15's that brake really well (outbraking me with BBK and semis) Theres also cars that are on the better side of a tonne, running 13's.

If I end up building an 86 race car, I'll be focussing on this area first. Trying to put together a package that works under a 16, or even better a 15 inch wheel. Then you have a MUCH lighter wheel/tyre combo, shorter gearing, arguably better braking, and its significantly lowered your COG without touching suspension geometry.

I apologise in advance for straying off topic here but I came across these wheels the other day. 16" super light and made specifically for racing 86s...

LINK

[diss7]

Originally Posted by Turdinator

I apologise in advance for straying off topic here but I came across these wheels the other day. 16" super light and made specifically for racing 86s...

LINK

I have already sourced some 16x7 +45 SSR Type C's, @ 4.9kg.

[Captain Insano]

I like those wheel specs.

[fooddude]

Are there still good shops and people that port and polish their heads for japanese engines (of course, I'm sure there is a lot that still do it in the hotrod/domestic world..but japanese head worx is a different story). I remember it was a big thing in the 90s..but it seems most people these days and in the 00s are going straight to FI.

Hopefully some good companies will start releasing NA cams soon...maybe Toda?

Imo, a relatively affordably priced NA build (without touching the bottom end) would be a good port&polish + a good set of cams + either mill a little off the head or use thinner head gaskets to raise the CR just a tad...all this could probably be done for around $2k ..which isn't too bad.

After that, I would say ITBs (since we are avoiding spending a ton of money on rebuilding the bottom end). But, like the cams/head work, I don't think anyone's released a good set of ITBs yet for the frs/brz. And, if they did, I totally forgot how much these usually go for...I think $5k-10?? And also an ecu to make it work and tune it of course.

The last step and extreme setup would be a bottom end build. Stock is already looking honestly decent with 12:1 pistons (similar to ITR already ). But, maybe we can go 13:1 or 14:1 forged pistons. Finish it off with lightened and forged con rods and lightened high rev crankshaft. This will surely make it into a high rev, high compression, monster. But, this would be beyond the budget of 99% of us lol.

Realistic for enthusiasts with normal budgets... I would think that a port&polish + camshafts are the best way for NA.

For hard core racers and people with big budgets... the above (cams + port&polish) + ITBs + fully built bottom end for NA.

[makinen]

Originally Posted by diss7

I have already sourced some 16x7 +45 SSR Type C's, @ 4.9kg.

I'm using 16x7.5 +35 SSR Type C's, 5.6kg.

[350matt]

Originally Posted by fooddude

Are there still good shops and people that port and polish their heads for japanese engines (of course, I'm sure there is a lot that still do it in the hotrod/domestic world..but japanese head worx is a different story). I remember it was a big thing in the 90s..but it seems most people these days and in the 00s are going straight to FI.

Hopefully some good companies will start releasing NA cams soon...maybe Toda?

Imo, a relatively affordably priced NA build (without touching the bottom end) would be a good port&polish + a good set of cams + either mill a little off the head or use thinner head gaskets to raise the CR just a tad...all this could probably be done for around $2k ..which isn't too bad.

After that, I would say ITBs (since we are avoiding spending a ton of money on rebuilding the bottom end). But, like the cams/head work, I don't think anyone's released a good set of ITBs yet for the frs/brz. And, if they did, I totally forgot how much these usually go for...I think $5k-10?? And also an ecu to make it work and tune it of course.

The last step and extreme setup would be a bottom end build. Stock is already looking honestly decent with 12:1 pistons (similar to ITR already ). But, maybe we can go 13:1 or 14:1 forged pistons. Finish it off with lightened and forged con rods and lightened high rev crankshaft. This will surely make it into a high rev, high compression, monster. But, this would be beyond the budget of 99% of us lol.

Realistic for enthusiasts with normal budgets... I would think that a port&polish + camshafts are the best way for NA.

For hard core racers and people with big budgets... the above (cams + port&polish) + ITBs + fully built bottom end for NA.

its already at 12.5:1 Compression ratio, so rebuilding it to gain 0.5 ratio for about 1% gain isn't really cost effective

thing is whats the bottom end good for on rpm anyway?
as folks are saying it needs a stronger valve springs to up the rev limit so yes you also need some cams and a shorter inlet tract to get it to tune higher up

but what are we going for here on standard pistons, rods and crank

9K? 10K?

Is anyone doing this and doing it reliably?

I'd say cams are coming but I doubt they'll push the rev limit up

[fooddude]

Originally Posted by 350matt

its already at 12.5:1 Compression ratio, so rebuilding it to gain 0.5 ratio for about 1% gain isn't really cost effective

thing is whats the bottom end good for on rpm anyway?
as folks are saying it needs a stronger valve springs to up the rev limit so yes you also need some cams and a shorter inlet tract to get it to tune higher up

but what are we going for here on standard pistons, rods and crank

9K? 10K?

Is anyone doing this and doing it reliably?

I'd say cams are coming but I doubt they'll push the rev limit up

Good questions. I don't think anyone would know the real answer to what the bottom end rev limit would be, except insider engineers at subaru/toyota, or maybe subaru engine builders with solid experience. I bet the bottom end/crank would have to be specially balanced at 11-12k+ (probably even a lot more for safety headroom) to be able to safely rev to 9-10k. Just my guess tho...of course I'm not an engineer; just a lowly garage mechanic hobbyist lol.

[D K]

NA power:
FB25 crank
Custom rods
14.5:1 pistons
e98 tune
~210-220 to the wheels

[stevo_12v]

Originally Posted by diss7

It's hard for me to thoroughly comment as not all specs are known. But it does seem heavy.

My 86 (Base 86 in NZ) was 1198kg with a quarter tank of gas, so 1180kg. I've then taken out 20kg of interior, swapped a 20kg seat for a 5kg Bride, and have a track pipe, swapped the front brakes for Wilwoods, and use se37k's on the track, (which are basically the same as the stock 16" enkeis) So I'm confident I'm below 1150kg. Taking the rest of the interior out, (remember the other 20kg seat is still in there) Replace battery, flywheel, remove crash beams, window washer bottle, and you're under 1100kgs in my eyes.

I think there is too much focus with these cars that bigger is better. For example, why run 17's or 18's on a track car. Why not 16's? Because of the brakes. Well, there are plenty of cars at the race track that weigh around 1000kg running 15's that brake really well (outbraking me with BBK and semis) Theres also cars that are on the better side of a tonne, running 13's.

If I end up building an 86 race car, I'll be focussing on this area first. Trying to put together a package that works under a 16, or even better a 15 inch wheel. Then you have a MUCH lighter wheel/tyre combo, shorter gearing, arguably better braking, and its significantly lowered your COG without touching suspension geometry.

I like the way you think(16's), the bad part is finding good track rubber that is cheap for that size though. Btw, just curious if you've weighed your car at a weighbridge?? I myself have OCD about the car's weight, recently checked at the local track weighbridge and I'm at 1205kgs on exactly half a tank of petrol.

[1086]

True but its getting closer to 200 whp on 91/93. I saw a thread, I would need to find it, where someone hit 193 whp on 93, which is pretty darn good.

[diss7]

Originally Posted by stevo_12v

I like the way you think(16's), the bad part is finding good track rubber that is cheap for that size though. Btw, just curious if you've weighed your car at a weighbridge?? I myself have OCD about the car's weight, recently checked at the local track weighbridge and I'm at 1205kgs on exactly half a tank of petrol.

I weighed it at my mates workshop. He had a shock/brake tester, that also measure weight, so I got corner weights and added them together.

I was going to run either 205/45/16's or 225/45/16. Toyo make a few models in that size, R888, R1R, T1R; Federal have 595 SS and EVO in those sizes as well. All around $200 - $280, which isnt bad in NZ.

[wrxgoose]

i managed to get 200.5 on 93 octane. it's in my build thread before the box of happy. We might have been able to push it beyond 200 with more work on the tune, but not sure.