im having some issues in my car and i dont know why. let me start about 6 month ago i put a street ported turbo II engine with atkins apex seals alll new seals, 8.5:1 rotors with couterweights, on my 89 GTU. i decided to use the stock N/A N351 ecu and retarded the timing 5 degree because i didnt have any money for a greedy emanegment that im planning to buy. well in the past 6 month i put 680cc secondary injectors, FD fuel pump rewired, apexi Safc controller with low maps at -20 and hight maps from +5 at 2500 rpm to +20 at 8000 rpm,rb 3" down pipe, with magnaflow 3"presilencer, corksport 80mm catback , 14x12x3 front mount IC with 2" turbo piping and stock TID with the N/A AFM and a K&N cone filter. the turbo is a S5 and i ported the small wastegate 1MM bigger and the bigger hole i didnt do nothing but the plate cover it. ignition i have a MSD 6al on leading and spark plugs NGK's BR7EIX gapped at .048 on leading and 9's at .032 on trailing i have. ok the thing is it pulls hard as hell from 2200rpm up to 6K and the boost start dropping to 6 psi and at 7k it just like doesnt have nothing else. this is on 3rd gear same with 4th and same with 5th it start at 10 psi and drops to 6, no knocking no missfiring just flat. so what im doing wrong or whats wrong? it been doing that since day 1 i put that turbo engine. does anybody knows? thanks

eddie

 

fuel cut maybe?

 

well there's your problem! stock turbo

easy solution, shift when power drops off

 

Waitaminute, are you still using the stock non-turbo N351 ECU???

Second, it's totally normal on what you are seeing.
Boost drops off at the top end.

BTW, if those iridiums are "heat range 7", they are too hot for your engine!


-Ted

 

RETed
Waitaminute, are you still using the stock non-turbo N351 ECU???

yeah is running fine with it. i retarded the timing and it runs even better

RETed
Second, it's totally normal on what you are seeing.
Boost drops off at the top end.

normal? and why theres no power after 7K? it shouldnt have at lease my engine past 7K or the turbo choke the engine that much?

RETed
BTW, if those iridiums are "heat range 7", they are too hot for your engine!

well, i ask this question before in this forum and as far i understand i have to use 7's for street so the car doesnt foul, what heat range you recomend?


Eddie

 

I Have A N333 With The R-tek In It If You Want To Do It The Right Way. Plus It Might Be The N/a Pressure Sensor Messing Things Up. I Have One Of Those Also. Pm Me If You Want To Buy Them. I Believe There Is More Power And Reliability To Be Had With The Turbo Ecu And Accesories

 

Dude, I would recommend you get rid of it and find a turbo ECU or go stand-alone.
You're driving a ticking time bomb.


The turbo is too small.


I would run at least all 9's.
People have been getting away with running all 10's, cause the iridiums don't foul very easily...
You can get away with running colder iridiums, cause their fouling resistance.
Running all 7's is asking for trouble, cause you take a chance of pre-ignition at the top end.
If you were running normal, resistor spark plugs (i.e. BUR7EQ's), then running all 7's would be okay.


-Ted

 

i will put a turbo ecu sometime soon it just i dont have the money for it, i have to save it. well the turbo choking the engine doesnt bother me so im use to it. ill wich the spark plugs soon i have another set of 9's here thanks

 

i need a N370 ECU and Hraness because my car is a 89 it would be hard to adapt an older harness on a 89-91 rx7

 

if i go for a hibrid turbo will it do the same thing? and what about using 8's for iridiums?or they still hot?

 

ironically, the streetport is killing your top end also, the turbo cant come anywhere keeping up with how much air the engine is taking in now. a good hybrid could hold boost to redline, but they have big problems with boost creep from what i've heard.

your best bet is to FIRST get a standalone like reted said, i cant believe its running as well as it is, but i wouldnt trust that set up for a second. SECOND, get a nice turbo upgrade be it aftermarket big turbo (to4e or similar) or hybrid. for now, just shift sooner and accept the fact that stock turbos suck above 6000 rpm's. i would know, i also have one .

 

I am running a very similar set up and using the stock turbo w/ a ported wastegate and throttle body. I use the stock turbo because #1 its new and #2 because i am not wanting to push my car to 7k rpm's.

Please remember that your motor is ported and the stock intake/turbo will absolutely not work effectively at those rpm's because your motor is no longer designed for those rpm's at boost. Especially w/ the stock turbo.

Also keep in mind that runnng a t2 at 7k rpm's all the time is not a good thing. 6k is all the farther you need to go under boost, just learn to shift a little earlier and you will find that you will get better results keeping your car under boost rather than it falling off and then you going into another gear. If you want higher rpms and higher boost you are going to have to get a bigger turbo.

But with all that extra boost you are going to have to upgrade other parts too. So this will not be just a turbo upgrade. Keep in mind that the stock turbos on these cars are very worthy and with just a ported w/g you will see good results.

 

Welcome to the world of an undersized turbine. Your stock TID is also to restrictive and will build slower boost and taper more up top but it will taper anyways with that turbo.

 

damm, yeah im planning to change the ecu like i said before, the turbo, well i just have to deal with it. im not planning to change that for a while. im not looking for high boost or high RPM just i was wondering about it because i thought is was verry odd. the power that my car have right now is verry good and i dont think i need anymore because is my daily driver. thanks