adamk

Hi everyone, im Adam from Lincoln (uk) ive just got myself a 1993 fd RX7 type r in silver totally standard beside de-cat and some air filter from WGT!. the engine has done 15K since a recon. (£3000)
Im a keen home mechanic so I like to undertake most maintenance myself where possible! anyhow.... the rotary is a totally differant monster to me so im a bit worried!

Im having a few minor problems with the car and im after a little advice and guidence. any help or advice will be great I have 1000's of questions. Ok here I go:

Im quietly dissapointed with the speed performance! im sure something just ant quite right?

where do I tap in a boost gauge ( on the inlet manafold?) and what figures will I expect to see?

Is it normal to get a small "peak" in power between the 1st and 2nd turbo changeover round 4k ish?

My air con is constantly active ( on the clutch mec) I have had to unplug it to stop the pump! also the air con does not work? where do I start?

What grade oil and manufacturer do you recomend? I understand this must be mineral!

should the car backfire? is this normal?

Regarding upgrades, doe the car have a mappable ECU as standard?
Do you have to get a mappable ECU when performing a suttle mod such as a full exhaust system in order to keep safe running?

what bolt on mods are most effective? are there any tweeks I can do on the standard car i.e is there a safe boost I can run on a stock ecu map?

Finally and most importantly.
I have a funny tapping/popping noise from the manafold/turbo/upper downpipe area is sounds like a blowing/cracked manafold on a normal piston engine! is this a common fault? is it normal? what could it be? It keeps in time with the engine and is there all through the rev range! it sounds bloody horrible!!

thanks for looking any help would be great!
cheers
Adam

bajaman

Wow. A lot of questions for sure. Let me be the first to suggest using the SEARCH function with carefully chosen key words to help you in the Forum.

Some of your questions have simple answers, some are much more complicated.
For example, there is already a port on the intake for hooking up a boost gage.

Your A/C problems are odd. If the compressor is turning (clutch is engaged) and you aren't getting any cooling effect, that is strange. If you are low on refrigerant then the system won't allow the clutch to engage.
So that is a whole big issue to resolve right there.

Oil recommendations are 10W-30 for cooler climates, and 20W-50 for warmer. Mineral is recommended by the manufacturer as you've noted.

Backfiring is not normal.

Boost "transition" or a slight loss of power whilst the primary and secondary turbos are...well, transitioning....is normal.
If you are even slightly disappointed with the car's performance, something isn't right unless your normal daily driver is a 600 hp RUF Porsche...lol! Lots and LOTS of things can affect boost, some simple some very complex.

The car does not have an easily re-mappable ECU. Most folks go aftermarket with something like a PowerFC though there are some 'piggyback' units out there.

It sounds like you may have a cracked exhaust manifold. This would explain the noises and loss of power. Not good.

Most commonly done modifications include a downpipe to replace the pre-cat, a modified intake system for better airflow, an aftermarket exhaust system with various components, upgraded radiator, upgraded intercooler, upgraded fuel delivery, addition of boost gauge.

There is a LOT to know about these cars.

scotty305

iTrader: (2)

Check out the FAQ, if you haven't already. Skip to the bottom section, there's a lot of advice written after the links section.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/faq-3rd-gen-other-useful-links-68640/

The FAQ has a link for Boost Gauge Install, that should get you started. In the page that it links to, there will be another link describing the "boost test," you should see 10 psi of boost in 3rd gear, with a dip down to 8psi when the second turbo kicks in (around 3500-4000 RPM).


You will notice a surge in power when the second turbo kicks in, this can spin the car if you're using full throttle while coming around a corner, especially in 2nd gear.


The factory ECU is not mappable, and will not work well above 10psi of boost. For this reason, it's usually a bad idea to remove the main cat converter because the car will tend to make more boost than the ECU can deal with. You also begin to run into the limitations of the fuel system.

The RX-7 runs pretty rich, so it's not uncommon to hear backfiring if you remove the main cat converter. I don't recommend this, for the reasons described above. If you're hearing misfiring at idle, it's possible you just need to change your spark plugs.


Funny noises are very difficult to diagnose over the internet, you might want to bring the car to someone who is familiar with FD's and get their opinion of it.


Best of luck,
-s-

dgeesaman

iTrader: (7)

"whilst", haha. If he were canadian, would you have added an 'eh?'

Dave

rexhvn

Im quietly dissapointed with the speed performance! im sure something just ant quite right? Check your boost pattern...

where do I tap in a boost gauge ( on the inlet manafold?) and what figures will I expect to see? Yes, the manifold, your pattern should be 10-8-10.

Is it normal to get a small "peak" in power between the 1st and 2nd turbo changeover round 4k ish? If your FD is manual, you will feel the second turbo come on at 4500rpm, giving you a BIG rush! If an automatic, the second turbo will come on at 4000rpm, again... giving you a rush!


What grade oil and manufacturer do you recomend? I understand this must be mineral! Debatable... better of searching for that one... there are threads with synthetic vs...

should the car backfire? is this normal? Your FD could be running rich? My FD rarely backfires, and that only occurs when i'm deaccelerating..

Regarding upgrades, doe the car have a mappable ECU as standard?
Do you have to get a mappable ECU when performing a suttle mod such as a full exhaust system in order to keep safe running? Yes you can remap the standard ECU, but there is no need to just for an exhaust upgrade.. i do recommand a power fc ECU later down the long run if planned for more mods... remember... the more mods, the less reliable.

what bolt on mods are most effective? are there any tweeks I can do on the standard car i.e is there a safe boost I can run on a stock ecu map? ON the stock ECU, I wouldn't put it more than 10 psi which is stock... but i'm sure 11psi with some mods would be fine? I suggest an exhaust, downpipe, cat etc... play a role in relaibility also!

Finally and most importantly.
I have a funny tapping/popping noise from the manafold/turbo/upper downpipe area is sounds like a blowing/cracked manafold on a normal piston engine! is this a common fault? is it normal? what could it be? It keeps in time with the engine and is there all through the rev range! it sounds bloody horrible!! No its not normal! You'll have to look around... or search again... hope that helps! And good luck!!!

adamk

Ok guys thats great! thanks very much for the info

Ill be sure to be asking more questions!

Ill be stripping the m/fold 1st job then ill check for pipe splits etc stick on a gauge and see the pressures hopefull do this 10-8-10.

I cant get over how complex the boost system is, Im used to a renault 5 turbo!!!

Thanks again

Adam

gio64

iTrader: (1)

I'd put the boost gauge on first. It's got to be the easiest job I can think of from my part newbie part not very experienced mechanic position I can think about... And there is a nipple on the Upper Intake Manifold that is just for that. Plug plumbing in it, route to cabin, hook to gauge and you're good to go!
After doing it, I cannot believe I was driving around without it, eh (reference to the "if you were canadian post before, no harsh feelings, just playing along ).
Furthermore, if you have a boost spike (I am dealing with that right now, due to improved intake air flow), you better solve that immediately, or you could (if your car has stock fuel delivery and electronics) kill that beautiful rotary of yours...
Just my 2 CDN cents...
Giovanni

adamk

Funny you should say that, The car is fitted with a fancy air filter, yet I have a recipt for "attention to boost" on the same day as the filter was fitted (from the same tuner) so I hope its ok!

adamk

Ok then, Am I better attacking the exhaust m/fold from above or below?? or both? I cant even see the turbos let alone remove them .
To be honest im quite looking foreward to ripping it to bits, see how it all works! Ill get chance to see the condition of the turbos n all. and clean it all up on the way! Just best make sure I take some diagrams/drawings on the way.

adamk

Another quick question, wht bhp should my car be? 255? (give or take 20bhp)

dgeesaman

iTrader: (7)

If you put it on a dyno, a stock car does 215-225rwhp. The book listed flywheel hp was 255.

Dave

adamk

I could cry, its my hot side turbo inlet m/fold that is cracked and one of the studs is snapped iff on the main exhaust m/fold. blowing like a ******* and performing like a 1.3 nova SR!!!
3 weeks ive had this car what a stinker of a thing to have happen!!!!!

And its going to cost a fortune!

rotoman2

The stock turbos all develop cracks on the inlet side. Just replace the whole thing. I found a low milage unit for a temporary fix on my 93. Or maybe it's time to go with a single stage anyway.

dgeesaman

iTrader: (7)

The snapped stud needs to be fixed/removed.

The cracks in the manifold are normal. As long as they don't extend past the gasket sealing line, you can put the turbos back on.

Dave

adamk

Na its quite a large crack and it blows through it also, as well as the stud!
tell me more about this single stage? do you mean single turbo conversion?
Cheers

rd_turbo

iTrader: (4)

A single turbo conversion, along with the removal of 'the rat's nest' is such a great thing to do if you're looking to simply things under the hood. Another thing you can do is convert to a non-sequential setup. That allows you to eliminate a few things. There is a lot of information on that, so 'search' is your friend. I'm not sure if you have mandatory emissions testing in your neck-of-the-woods. If you don't, then there are further simplifications that can be had. Start by identifying what type of ECU you have, if it's factory, you really need to do something about that. I recommend a Power FC if running an aftermarket ECU doesn't violate any local laws. The Power FC continues to be a popular unit, which interfaces nicely with the stock wiring harness (with a few minor modifications). Get those twin turbos off, fix whatever broken studs you have, look into non-sequential mods, including wastegate porting information and consider all the options and start by doing what makes total sense to you. Also check the condition of your fuel pump - a common upgrade is to a Walbro 255 LPH. Welcome to the insane world of fire-spitting rotary dragons......by the way, when it comes to owning an FD, insanity is a ceretain outcome...resistance, as they say, is futile