JDM-AREX7

Hi guys... i recently bought a RX7 FD3s ... it had a full rebuild at Haywards Rotary with 100 miles on the engine and a NON Sequential conversion (seems like the poor mans conversion as far as i can see)

Specs: Catback / Apexi twin intake / Blitz BOV / JDM Rx7!!!

... so i took it home... ran it in propperly and didnt rev it hard for a couple of thousand miles... So then started running in the higher RPMs... and one day i decided to boost it... runs fine untill 5000 rpm! boosts from 4000 untill 5 (reaches 0.7 bar) and after 5k rpm there is a huge loss of power and the boostgauge acts funny (it keeps jumpin between 0.4-0.7 bar) checked for leaks and didnt find anything ... BOV's fine & even plugged the RCV pipe as i thought that it may be venting boost for some reason... do you guys have any ideas!? Im really sad and angry at the same time didnt buy my dreamcar to be driving it under 5000 rpm and as its non sequential theres no fun under 4000 rpm anyways

GreyGT-C

Where are you located?

It's been a while since my car was NS, but i cant really think of much that would affect boost at that RPM.. Even with an NS car, you should be getting a good amount of boost WAY before 4k rpm though. Still have the stock cats on it? Check to see if they are clogged.

JDM-AREX7

stock cat still on! No precat as its a jdm! ... mhhh ... a clogged cat would affect overallpower wouldnt it?! ... thats my guess :S ... checked for boostleak but couldnt find any... but if you say i should be getting boost even earlier then i might take off everything and check again... but why would it affect power only over 5000 rpm

rotorjeff

I recently broke in a new engine on an FD. It now has 1700 miles on it. I followed the protocal of no boost and low rpms for 1000 miles, then up to 4000 rpm to 1500 miles. There have been a few times lately with constant acceleration in 5th gear at about 105mph that I experienced a temporary loss of power. My car has an open down pipe with a high flow Bonez cat and Racing Beat exhaust.



I recall reading somewhere that with the stock ECU, there is a boost level were boost is temporarily cut.



I am just about ready to connect my Knock retard device and Power FC. This should solve the problem.



These cars are susceptible to detonation at high boost, low fuel input. A knock retard is a must for higher than stock boost, especially with a single turbo. I am running the Efini 1999 twins in my car. I like the low RPM torque generated with the sequential twins.



My recommendation is to install a knock retard and Power FC.

Signal 2

Obviously it's still no substitute for a decent tune. The other thing is, it seems like what is a high knock level on one car may not be so high on another.



Maybe the BEST combination would be a standalone for tuning and to monitor knock, a reliable AI system and if you want, a knock sensor just in case.

thatpoorguy

check which valves are hooked up. some of them can affect whether the secondary turbo spools at all if the vacuum line is unhooked