I am thinking of adding a 1/2 plenum spacer to my 04 G35C APS TT at ~9.5PSI

The car is tuned very rich high 10's low 11's

Would it be safe to add a 1/2 spacer or wait until I can add it and retune.

Just wondering how much of a real impact it will have on the tune.

 

if you have a wideband gauge in the car so you can verify the A/F stays safe, then you could try it and see how it goes. otherwise i wouldnt.

 

Wideband isnt installed yet

 

Not sure is anyone can give you a definate answer on this... every car is different. What works for one may not work for others.

Why take the chance?

 

Im not taking the chance thats why i posted up to confirm its not a good thing to do with out a retune. just dont wana spend 500 bucks to retune my car because of a plenum spacer, ya know?

 

it wont be that expensive to retune. U are now just fine tuning it where it should only take at most 1 hr of tuning. If u changed injectors then yes u have to retune from the start but your fuel setup is the same so its basically adding a little more fuel up top and u are done.

Cost 200 (spacer) + 200 (tune) = $400= 10 hp extra. Is 10hp extra worth 400 dollars? That is up to u.

 

SAM at GT Motorsports qouted me 500 for a retune. Flat fee. The car was last tuned 2 years ago at brainstorm and is only making 390 or so whp, so it would actually be installing a 1/2 plenum spacer, and a better flowing exhaust and test pipes and retuning i should be at around 440whp.

Also i think the 1/2 spacer gives more than a 10hp gain with FI

 

spacers doesnt really give u much peak hp so I wouldnt really expect more than 10 peak hp. If your tuner is asking 500 flat fee then get everything done at once before u get it retuned. Or u can buy the spacer and dyno it with it on to see how your a/f is at and if its good keep it on and if it leans it too much take it off and wait until u get all the extra parts for the retune.

 

I really need to get my damn wideband in there, i just got the car 2 weeks ago from another forum member and he never installed a wideband, just EGT, boost, and Fuel Presss. I dont even have a oil press gauge!

 

well, u did buy my oil sandwhich adaptor, so now u can use that for the oil pressure gauge. What kind of fuel setup are u using and are u running on stock block?

 

Oh yea I totally forget that was you haha, Stock Block, Fuel system is what comes with the APS kit, its has a FPR, next weekend im installing the HKS DLI II with new NGKs and the HKS EVC 5 boost controller, next month i wanted to do the 1/2 plenum spacer and 3.5 aps test pipes with probaly now the APS 3" exhaust

 

u might need bigger injectors. The kit usually comes with 380cc and thats maxed out around 380-390hp. Does it come with the aam return line? If so, u dont need the extra fuel pressure gauge in your pod so u can replace that with the wideband.

 

are those rotoras on the 350z u trying to sell? if so i would love to buy them off of u, hehe

 

The Z is back to stock now, Need to update the pic! Sold the rotoras for 3100, Fuel press. isnt bad to have

 

if u have one in the engine bay then why do u need another one? Also, 440 hp on a stock block might go booom

 

Ill take my chances , there isnt one in my engine bay, so thats why i feel a fuel press. gauge in cabin isnt bad, nice to see what its at. Im going to sell my Greddy Electronic boost gauges and replace it with a oil press gauge. Then my HKS EVC will be mounted were the ash try is and next to it will be my wideband, So it will display boost and AFR down there. Should be good.