FD technical help please
 

Hey guys i am looking at buying a 1997 RX7 Fd S7 V2 that has had a engine change and a S6 engine put in it.
Now it wont run more than 5 psi boost and have been told that the second turbo wont kick in as it is still running the s7 computer and need to either get a aftermarket computer or do a single turbo conversion.
Is this true or can i put a S6 computer on it and it will be fine or can you not run a s6 computer on a s7?
I am new to twin turbos so not sure how they run.
The owner also said he has had all lines and solenoids changed and thats how they know its the comouter

First im not trying to be rude but if you dont know much about the car and dont know what the problem exactly is and your trusting someone else you could be in for big trouble. Ive bought and sold several cars in my life already and have looked at a bunch more. People will say they think they know whats wrong but in reality they have no idea.

Also think about how the rest of this car has been put together if the engine is just thrown together from a bunch of different genrations. It may be a good deal now but in the end you could be dumping a ton of money into it.

My advise is to read all of the FAQ for the FD. Not only will you understand the car better for yourself you an also tell when people are telling you a load of BS just to sell you a car. The service highlights manual is awesome. It has flow charts that show you how the various systems work, it's a good read. If I were you Id spend about six months on this forum reading about the FD everyday. Reading the threads that come and familiarizing yourself with the community. Good deals come up pretty often here on the forum and Id rather pay more money for a well sorted car then get a deal especially with an FD, Im sure youd rather be driving it then working on it all the time cause its broke.

that car sounds like trouble.
im betting the ECU is fine, and he/they screwed up when doing the solenoids or mixed up some hoses or something.
the engine block themselves are the same.
also stock FD's run around 10psi, so i dont understand why you would want to limit it to 5 psi unless it was just untill problems are fixed.

If it's Au delivery rather than an import, S6/7 ecu will interchange, if it was a Jap car, you'd be hard pressed to use a S6 one without a whole host of other changes. I'd check codes as a first port of call.....diagnostic box....or sparky with scan tool.

That boost problem isn't uncommon, there's long running sagas on one of the aussie sites with people looking for magic fixes without getting their hands dirty - solenoids, actuators, lines, vacuum and pressure chambers should give you a good list of things to go through - if you did decide to buy - it would certainly be a bargaining point at any rate!

Definitely wouldn't take anyone's word they've done something correct, as the previous poster mentions.

It sounds like you've got a mess on your hands. You might want to stay away if you don't have assistance from someone with FD experience. Starting out with a basketcase car will be a real uphill climb for someone who doesn't have a lot of experience with turbo cars.

+1

Find a well sorted car to start with. Owning an FD requires knowledge and money. If you have little of one, you'll need alot of the other.

Also, please review the forum rules. Posting "help" with no other info as a title is prohibited. It doesnt help anyone who searches in the future.

Well i have both, i am a mechaic and have a first gen and a second gen drag car built by my self, also money is no drama earning over 170 a year dont think a little problem like this will be a big drama.

Found out the owner has fitted the original s7 turbos and it still does it so its not the turbo stuffed.
Prob be a solenoid issue i am thinking as it has to produce 8psi from primary turbo for the secondary turbo to kick in.
It made 196hp on 5 psi on dyno only on primary turbo.

Mate i have a lot of experience with turbo cars just havent played with tt yet.
I have a fc drag car with a 13b BP running a GT45r turbo on 32psi so think i know a bit about turbos.

No it is a jap inport s7 V2

Excellent. You are definitely ahead of the game. Short of the car falling in your lap, or a personal deal, why dick with a swapped car with issues? There are many clean, sorted examples out there.

If you are set on keeping the sequential setup, then it's going to be a series of test to ensure each component is working properly. Otherwise, parallel twins work like a champ, and its very easy to setup.

http://fd3s.net/boost_problems.html

More info. Not sure how much of this transfers over to S7 engines.

http://www.rx7.org/Robinette/boost_controller.htm

http://www.rx7.org/Robinette/turbo_s...lification.htm