Bambam7

I'm just curious.... How much boost would you normally put out on a stock turbo with intake, 2 1/5" exhaust, street port.... blah blah... on a STOCK turbo.
I have almost everything together for my turbo conversion, with the execption of the turbo and manifold.
I have a nice big FMIC, an S-AFC, injectors, pump, all that.
The limiting thing is, my engine is a high-comp '90, with 9.7:1 rotors.
I want to limit boost to less than 10 psi max with the big intercooler... I haven't gotten the actual turbo yet, becuase I am undecieded on going with the s4, or s5. I think I may go with the s4, because it boosts 1 or 2 psi less...

Thanks for the input!!

Grimlock

actually i believe the series 5 turbo is the one you want. the 4 has severe boost creep. i get 13psi easy! i have heard of peeps putting the 5 on and only getting 10psi cause of the better waste gate design. but im not certain!!

Bambam7

Would that be cleared up by porting the wastegate??
s4 turbos are a lot cheaper and easier to find.

Erik

i see about 6psi in 1st gear, 7psi in 2nd, 8psi in 3rd...haven't ever gone WOT in forth...

this is with 91 T2
intake, FCD
rebuilt turbo/ported wastegate
2.5 dp/mp/catback

quicker than stock with the same boost...

vosko

iTrader: (4)

you can port the S4 wastegate but the S5 is still better. my car with 3" dp and mp and stock catback would hit 7.5psi and very rarely spike to 10psi for a split second then back to 7.5psi. S5 turbo is bigger too!

Grimlock

yeah, porting makes a big difference but i still say you should get a series 5 turbo! i just saw one for sell with the manifold too! on thepartstrader.com go check it. i got mine for $250 turbo/manifold

Bambam7

Bump...
ouch

Oh- isn't boost creep to 12 PSI the same as actually boosting to 12 PSI? Except that you may not want it.

vosko

iTrader: (4)

say you set boost to 10psi it creeps to 12psi that can be very bad if you don't have enough fuel

Bambam7

OK- That's what I thought.

Poppinrex7

i used to hit 15 psi with jacobs ignition, apexi bov, tid, s-afc, avc-r, fuel pump, greddy fmic, 720cc inj, clutch and flywheel, jet chip, fcd, intake and 2.5" bonez d.p. and cat, greddy power extreme catback, but now i have an S5 upgraded turbo and manifold...

vosko

iTrader: (4)

umm you have a jet chip and fcd ? jet chip should get rid of boost limit!

chatch

I hit 10 psi in first and second. Havent got to wind it out in 3rd. (Damn Clutch!) But i suppose it should hit around 13.

Grimlock

so what do you hit now?

Kahren

iTrader: (13)

buy a NA and u will have no problems

SonicRaT

iTrader: (6)

vosko, what mods are you running to get your 13.9 sec quarter?

vosko

iTrader: (4)

dp,mp, act race clutch, 19lb flywheel, cone filter, panspeed ecu, 11psi bleeding to 6psi at redline, upgraded garret turbo (slightly larger than stock S5). soon to have apexi n1 catback and greddy manual boost controller. the ultimate goal is low 13's with 14-15 psi on race gas

SonicRaT

iTrader: (6)

I would kill to get my GXL->T2 down to 13's, though I suppose I need to finish building it first. But so far, I have a RB dp/mp to open pipes (no mufflers, yeah, i know it will be annoying loud), oem clutch/flywheel, no AC/PS, i've tried to strip out some excess weight, probably down to about 2,600lbs or so. Cone filter, stock ecu with a fcd, and going to get some larger injectors. I was thinking of getting a T04B for a hybrid, but I'm not sure yet. Oh, I'm also going to be running a starion front mount intercooler until I can get a nicer one. What do you think I could pull a quarter in if everything else is stock? (Oh yeah, walbro fuel pump too)

vosko

iTrader: (4)

i would get an aftermarket clutch your gonna smoke that stock one cough *act race* cough . my TII only weighs 3100 lbs with me in it! with all that you should run 13's it will take practice though. if your gonna get a upgraded turbo www.micturbo.com has a stock unit with T04E frontside for $550 ! that should be real nice

SonicRaT

iTrader: (6)

T04E, *drool* er uhm, yeah! I'm hoping to get 13s after some major practicing with the oem (damn straight that thing's going to be gone in a month) I'm working on lightening it up some, and I want to get some power out of it when it's finished. If I can't do better than 15 in it, I'm going to be depressed! My car should weigh around 2800 with me in it and on the track ready to go. Are you running a series 4 or 5? Never did pay much attention to what year your car was!

PraxRX7

with a stock exhaust with well over 175,000 miles on it I still make 7psi of boost.

Bambam7

I am now getting a turbo and manifold for very cheap....it's an s4, so I'm going to port the wastegate obviously....
It also has 140K miles on it, but it's aparantly OK.
That's fine with me- because from what I've seen, I'm going to be struggling to keep the boost under 10 PSI.
I hope this will be fine on my engine!
Damn.... I'm running consistant 14.3 -14.5's ET'snow.... I should be deep into 13's with the tubo on!
What's the best way to keep boost down below a steady 8-10 psi with my intake and exhaust.....
Damn I don't want to blow this engine.... but I want more power, and have hit the (streetable, read:LOUD) NA wall!!

And poppinrex7- What are you boosting now with the S5 turbo? Lower boost and better ET's or what?

vosko

iTrader: (4)

i have an 89 turbo II. just gotta run it and find out

rx7_turbo2

I've seent the stock turbo take over 21psi on a semi consistant basis. This is not reccomended however.

sublimeracing

What would be the recomended max(safe) boost? [i've got an s4 but am going to swap manifold and waste gate w/ s5]

vosko

iTrader: (4)

stock turbos can run high boost but not for long!