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-   3rd Generation Specific (1993-2002) (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/)
-   -   how much hp can you get without having to upgrade ecu and not chaning boost?? (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/how-much-hp-can-you-get-without-having-upgrade-ecu-not-chaning-boost-76006/)

TobiasRX 05-01-02 06:18 AM

how much hp can you get without having to upgrade ecu and not chaning boost??
 
just curious

user 84205 05-01-02 06:49 AM

well you can upgrade all you want, but you will never get the full potential of your upgrades without a ECU or at least just a tune. I would say 300hp though, just a guess though, with all the crap people can get today

SaulV 05-01-02 09:39 AM

i WOULDNT RECOMMENT ANY UPGRADES BEFORE YOU DO YOUR ECU. Is just the way rotary engines work, If you dont want to blow your engine off within 50k miles. I will seriously recommend to ECU first.
If you do all the upgrades without the ECU. You stock ECU keeps thinking the car is still stock yet there is more Air flow coming in and going out. More gas will be used and eventually you will get the power out of the engine but the engine will give up on you because the whole engine is not timing right and that poor engine will just die quick. That is the RX7 owners nightmare....blown engine but is common sense!!

Our cars dont work like honda's where you can just puy anything. Their engines take it because there isnt a dramatic amount of horse increases. In Rotary engine. The Horse increases is noticeable for us and for the engine but not for the ECU therefor the whole engine will give up based on a untunned and untimed engine.

Peace
Saul V

Mahjik 05-01-02 09:49 AM

Without upgrading the ECU, I think you might be able to make to around 270 rwhp possibly.

As already stated, it's just safer to upgrade the ECU. If you don't plan on doing too much modifying, the M2 and Pettit reprogrammed ECU's will do just fine. $700 for a reprogrammed ECU is definitely cheaper than a $4000 engine rebuild.

TobiasRX 05-01-02 10:52 AM

ok, im not planning on upgrading my car yet anyway, i have only had the car for 2 weeks so the car goes very fast for me as it is.

Mahjik 05-01-02 10:58 AM


Originally posted by TobiasRX
ok, im not planning on upgrading my car yet anyway, i have only had the car for 2 weeks so the car goes very fast for me as it is.
Great! Just enjoy the car. Make sure you've had all the fluids and filters changed. Do the normal maintenance things before looking to upgrade. Check your tires, etc...

You know, one of the mods I did that was probably the most noticable was the Eibach Pro-Kit Springs. A very good modification that won't mess with the air/fuel ratio requiring an eventual ECU upgrade.

I wish I had done those springs earlier! ;)

phatmonky 05-01-02 11:03 AM

ECU or not. Go get a downpipe! :)

TobiasRX 05-01-02 11:23 AM

Im thinking of getting a downpipe, but im gonna spend my money on a boost gauge instead and then i want my car to shine.

93TTRX7 05-01-02 11:58 AM

Get the downpipe...it's always rule #1

SaulV 05-01-02 02:10 PM

Downpipe will mess you air/fuel ratio and eventually will kill you engine.
Downpipe will mess up the air flow and the ecu will go crazy because is not the normal ratio of air going in and out which will lead to a blown engine. My advise!
Proven theory!! but if you do it dont say RX7 arent reliable! is just that the owners dont do their homework to learn about the car. RX7 owners mess up their cars, and then blame it on the car. RX7s are reliable if you know what to do with them
Follow my advise
Saul V

Talek 05-01-02 02:30 PM

Even with a stock ECU adding a downpipe increases the reliability more than it decreases it.. the precat is a POS and likes to clog up, it restricts exhaust flow and causes the engine to heat up faster and hotter which can eventually contribute to hoses cracking and overheating and byebye engine.

SPOautos 05-01-02 02:55 PM


Originally posted by muzik3k
Downpipe will mess you air/fuel ratio and eventually will kill you engine.
Downpipe will mess up the air flow and the ecu will go crazy because is not the normal ratio of air going in and out which will lead to a blown engine. My advise!
Proven theory!! but if you do it dont say RX7 arent reliable! is just that the owners dont do their homework to learn about the car. RX7 owners mess up their cars, and then blame it on the car. RX7s are reliable if you know what to do with them
Follow my advise
Saul V


I saw a bone stock 3rd Gen dyno showing the a/f to be below 10:1 which means its very rich for 10psi of boost. You can add a few mods with no danger. I've also seen one with quite a few bolt ons with the stock ecu still at 10psi and it was still in the safe range.

The problem people run into is letting thier boost go above the 10psi factory setting. The ecu doesnt read past 10psi so if your running 10 or 13psi the ecu doesnt change a thing you still getting the same fuel/timing at 13psi as you were with 10psi. Most people run more like 11-12 eventhough they know they shouldnt and then have some small spikes alont the way and thats what blows thier motor.

The other thing that really blows ALOT of engines is dirty fuel filters. Change your filter every 15K miles.

As far as I'm concerned as long as you keep your boost to 10psi you can do intake, dp, catback easy with no problem, I ran mine like that for over a year with out a problem.

Later,
STEPHEN

neevosh 05-01-02 03:12 PM

I dyno'd 271@10psi with an 11:1 A/F ratio on what I believe is the stock computer. I had it sent out but it doesn't look like anything was changed. Mods are intake, DP, CB, and FMIC.


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