rx7jocke

So i decided to move past my 400hp s4 13bt stockblock and i am going for a RELIABLE 500rwhp track car (allthou i will try to keep it streetlegal so bridgeport and p-port is a no no since emissions will fail,

I already got the sipporting mods for either setup apart from uprated oilcooling and a twin plate clutch.

Is the 20b more prefered maybe with a streetport and some studs or will a 13b all out super deluxe block be cheaper and more suited for track use? i must say 20b torque is appealing!

budget is around 8 grand for the shortblock.....mind this is sweden where prices is a bit higher

Havoc

even if you wanted 300hp.. 20B is always preferable if you can afford it.

rx7jocke

the 20b does add alot of weight, and cooling issue, and to solve the cooling issue it takes bigger water/oil coolers= even more weight and all the added weight will be in the front :-/

and for the cost of the 20b u can go all out aluminum 13b with ceramic apex seals :-)

jetlude

iTrader: (9)

If its within your budget go for the 20Beast.

Turblown

iTrader: (12)

Power levels aren't high enough to demand 3 rotor . Unless you have a lot of money don't do the 3 rotor . 2 rotor on e85 is extremely reliable at 500rwhp on the track . 2 rotors can deliver 3 rotor powerbands if setup right . They just want make 650rwhp at 15 psi ..... Etc

Jason94R2

iTrader: (3)

Elliots IWG 8374 is the way to go on a 2 rotor for 500hp.

Jason

Howard Coleman

iTrader: (6)

"Power levels aren't high enough to demand 3 rotor . Unless you have a lot of money don't do the 3 rotor . 2 rotor on e85 is extremely reliable at 500rwhp on the track . 2 rotors can deliver 3 rotor powerbands if setup right . They just won't make 650rwhp at 15 psi ..... Etc"

i completely agree re the 2 or 3 rotor comments above.

a 2 rotor on E85 that makes around 400 rw at 5000 rpm. will greatly challenge available traction which is key for road racing.

further, the 3 rotor is a much more complex swap than most imagine. unless you set it back alot you will be having bump steer problems which is death to going fast. i have yet to see a bump steer "correction" kit that actual delivered zero bump steer.

front weight is evil for road racing. to go fast you want 54% rear weight. instead w a 3 rotor you will have a bunch more front weight.

do a 2 rotor right and go out and kick *** on E85 around 450/500.

properly setup you will be supersonic.

good luck,

howard

arghx

iTrader: (3)

I don't understand what's wrong with your current engine. The parts are cheaper (at least in the US, but I bet they are still cheaper in Sweden).

You probably don't think it will survive because it will crack an iron? I don't want to say that's overblown, but it's almost always too much spark timing or a mechanical failure that causes it. Why not just keep going with the engine you have and maybe change the turbo? and Isn't E85 available there?

Also, twin plate clutch? This isn't a drag car right? That's overkill man. Do you think it will slip from a roll or something? It just seems like you have this budget to build an engine when the shortblock isn't what will keep it together. It's the tuning, the fuel system, the right supporting parts. You're already most of the way there.

If you can go E85 with your current engine, and keep the fuel system holding up it's not going to blow up on you if you have enough cooling and the right spark timing. The way you crack an iron is from high combustion pressure. That's caused by knock/preignition or if you have race fuel/E85 too much spark timing causing high peak combustion pressure.

So here is what I propose. Keep your engine if you still have it in the car and running. Switch to E85. Buy an advanced, modern ECU with lots of capability (AEM Infinity for example) instead of say an ancient power FC or a bare bones Haltech. Go full flex fuel on it with an ethanol sensor so you can drive it on the street and adjust to seasonal blends. Go with a simple and reliable fuel setup (IMO, a single high flow fuel pump is best if you can make it work). Set up failsafes in the ECU in the event of overheating, overboost, lean out, all that stuff. That's how you make it reliable. If you know what you're doing you can address almost everything that goes wrong in the ECU (cut power if it starts overheating, gear based boost control, knock retard, all of that).

Now if you do need to put a new engine in there, go with something basic: A 2 rotor with good condition housings on stock ports or mild ports, and the rest is all in the right turbo and supporting mods. A 3 rotor will swallow your budget and take way too long to finish. I wouldn't go with any exotic apex seals either. I like the RA super seals because they can handle catastrophic knock better than others, even though they have a reputation for being harder on housings.

rx7jocke

thank you all for the input! i will take it into consideration!

arghx i will try you as good as i can:

1: I am gonna buy an efr 8xxx turbo either way, but my engine needs work if i wanna push more hp.. i made 384hp only on 16psi with my BB t04s and that was a dissapointment! will a big streetport really make that big of a improvement on a s4 13bt? wont a stock REW still have bigger ports?

2: yes e85 is avalible here and i have a haltech PS1000 with flexfuelsensor, FFE trigger, AEM coils, ID1300,4-port boost solenoid, twin gated manifold, an8 ptfe fuel lines etc etc so thats not the problem, the engineblock just ran out of breath around 400hp, the tuner said 1.2bar (17psi) was the max he would go on this block (non studded thin cast)

3: i just assumed a high hp(500) engine prefered a double plate clutch and i can get a excedy very cheap :-)

Howard Coleman

iTrader: (6)

if everything was just right you might have made 450 max w your TO4S/60-1. does it have a P trim turbine? what is the turbine housing A/R? if you were tuned correctly you probably have a flow problem. do you have a dyno sheet? EGTs? what is the brand of your IC and core dimensions and location?

you do have a nice selection of components.

if you can make the switch to a BREW i recommend it.

howard

arghx

iTrader: (3)

You may just have a more realistic (ie not inflated) dyno. 384 sounds right to me. I think I did in the 370s on my old T04S at similar boost levels at my local dynojet.

just change the turbo to a newer design. post your PS1000 maps so we can take a look at what you're doing.

the tuner didn't want to be steering the ship if something did happen. He would be eaten alive on the internet in his mind if he did in fact crack an iron. so tune it yourself. might as well do it on a way cheaper engine. if it pops, no big deal. I would hate to see you build another engine and have that let go.

What I did on my car was switch to S5 irons on a later build, and it was at 430 dynojet hp with a T04Z and too-big ports at 18psi on just USA 93 octane, approximately 98RON.

rx7jocke

Howard: Yes p-trim turbine ar 1,0 fully divided and i also have a s5 lim-->FD uim and fd throttle body everything portmatched, , no egt readings sorry and the IC is a big *** FMIC (no cooling problems since good ducted)

Arghx: i will post my map when i get to my laptop in a few hours :-)