maciek

Hi guys,

I posted a similar message in another forum (2nd gen) a few days ago, so sorry for re-posting. If I am out of line, let me know and I will desist.

I am really interested in everyone's feedback on my project. FWIW, I dont pretend to know a HUGE amount about rotaries, but I have done a fair bit of work myself without any major miseries.

I attempted a 20B transplant at one stage, but ended up selling the block due to time constraints (just didnt have the required countless hours to spend in the garage).

In the end I decided to go with a 13bt instead and with more sedate ambitions.

I have an 87 NA vert with a S5 13bt motor & drive-train.. I got a front-cut and transferred everything useful from it. I also got a T2 rear-end with a good clutch LSD.

To date I have done the following:
- Racing Beat 2.5" downpipe & straight cat
- custom 2.5" to 2x2.25" Y-pipe with straight mufflers
- pod air filter
- bleed valve set to 12psi
- stock fuel pump to 1l surge tank & Bosch 600hp pump
- flushed radiator & replaced thermostat
- large thermo fan

I am still running the stock Mazda computer, but I have by-passed the fuel cut (dodgy!)

I am aiming for around 300hp firstly, but would like to know how much further I can go without having to rebuild the engine for dowling, etc.

The car runs well, if a little hot at idle (hence the thermo & flushing cooling system). Its currently at the shop getting an aftermarket radiator (better safe than sorry).

Here are my thoughts on where to go from here:
- engine management (Microtech LTX-8, new coils)
- new plug leads (Magnacor?)
- injectors (will 1000cc secondaries do?)
- fuel reg (Malpassi/sard?)
- FMIC
- upgraded turbo (hi-flowed S5 turbo/TO4/TD07?)

I would appreciate any feedback from anyone about whether this is the appropriate order to go about things, and what else I could do in the interests of good power without compromising the engine too much.

What boost can I safely run in this setup and how much power would this produce?

How much hp can the stock S5 block handle? How much boost?

I have already researched with various engine builders & rotary workshops here in Australia.. but I have had a lot of conflicting opinion. I have also had friends who have been "reliably told" that they would get X horsepower after doing Y and Z, and when it came to the crunch (after spending hundreds of dollars with said workshop), they walked away with substantially less power and some **** poor excuse ("your block cant handle any more at this stage so we had to tune it down", etc).

I am not made of money and I have plenty of other projects, so value for money is an issue.

Any feedback & suggestions very much appreciated.


Thanks

Sponge Bob Square Pants

Stock block has proven to withstand high boost levels, such as 28-32 psi without problems, but this is not comman as first of all not many people run this much boost and second of all, not many people have the tuning skills and "emergency money" on hand to attempt doing this in the first place.

If you are aiming for 300 hp doweling is not necessary. It's hard to put down an exact HP number on when you should dowel an engine (some tuners swear by even never doweling street engines) but most would probably agree no doweling is needed unless you are aiming for 500+

LTX-8 is an excellent choice for EMS and it does have very good support in Austalia so that's good news for having it tuned and maintained if necessary.

You'll want to upgrade that exhaust system as well.

maciek

Thanks.. I know the exhaust is a little restrictive, but I couldnt go any bigger with the stock ECU. I cant afford to replace it yet so I will stick with this one for a while. It should be OK.

Any other suggestions as to:
- what size injectors to use
- do I need to replace the fuel reg - if so, what type?
- what type/size of turbo to go for

Will the Bosch 984 fuel pump flow enough, considering that it has a surge tank also?

Also, I am upgrading my radiator at present. What else is worth doing in the search for better cooling? I have been told an EWP is worthwhile. What about replacing the stock oil cooler?

I have also heard of a mod where an additional cooler is placed to cool the water coming from the turbo before it goes back into the block. A friend of mine used a trans oil cooler for this and it seems to be working.

How much power can I go for with those mods. I'm told a hi-flowed S5 turbo is good for a little over 300rwhp. I am guessing a decent T04 will top 400+, but is also a lot more expensive.

maciek

Any suggestions...? I would have thought someone had some tips/tricks/comments/flames...

$150FC

I don't an additional oil cooler is neccessary. There is another thread in the second-gen section regarding this. The stock water pump should be fine as well.

Are you looking for 300bhp or 300rwhp?

andrew lohaus

just keeep reading and doing seraches in the second gen forum. youl learn plenty. there hasnt been a whol lot new for these cars (hell, thay are atleast 15 years old) so pretty much anything you could want to know has been covered in there.

maciek

Trying to work out how to calculate injector sizing.

I have the forumula:
..or in my case:
..however this is supposedly calculated at 43.5 psi. I dont currently have a fuel pressure gauge, so I am wondering if there is a way to calculate the fuel pressure.

My fuel pump is a Bosch 984 which is rated at 600hp at 43.5 psi (I think). However I am also running 12 psi boost - should I add this to the 43.5 to get total pressure? Presumably this will affect the efficiency of the pump and hence also the injector sizing calculations.

$150FC

just get 2x720cc and 2x1600cc and you will have enough fuel for almost anything you'd want to do.