Supra Forums banner
1 - 20 of 107 Posts

·
Registered
Joined
·
2,437 Posts
Discussion Starter · #1 · (Edited)
****Update, last page


The car is a 94' TT auto, rmm downpipe, OEM catback, blitz SUS, 6k miles on new turbos, block, and head, non functioning egt and boost gauges (60mm greddy), and as of 15 mins ago the bleeder 't' mod.

I started getting suspicious when I didnt hit boost cut at WOT in 40 degree weather with a racing medalion and downpipe on. Plus it seems like I loose too much power/torque at anything over 4500-5k rpm.

Anyway, I went to o'riely and picked up some 1/4 inch fuel line tubing (didnt have any vaccume in that size......) a 1/4 inch vaccume t, and some screw style clamp bands.

Didnt want to cut the OEM line, so I used an 2 inch extension from the actuator inlet to the 't', to the original vaccume tube (which is the same interior diameter as the feul line I got ).

Anyway, clamped it all down, and went for a drive. The car seemed to pull better, but not the gain I was expecting. On top of that, I did not hit boost cut. It was 94 degrees outside, but it seems like I should still be hitting it.

Give me input please (I know I need to order a sensor for the boost gauge).
 

·
GO 'Cats!
Joined
·
1,001 Posts
Differential dx:
1) boost leak
2) #2 snail taking a dump
3) anyone else.

Rx: Leak Down, TTC trial

Report back
 

·
Registered
Joined
·
2,437 Posts
Discussion Starter · #3 ·
bonz said:
Differential dx:
1) boost leak
2) #2 snail taking a dump
3) anyone else.

Rx: Leak Down, TTC trial

Report back
#2 snail?

My money is on a boost leak or malfunction in the mass of sequential shit.
Dont have a boost leak tester, or know how to do it.

And havent been able to find the thread on the quick way to go to ttc, anyone have the link?
 

·
GO 'Cats!
Joined
·
1,001 Posts
twistedmethod333 said:
#2 snail?

My money is on a boost leak or malfunction in the mass of sequential shit.
Dont have a boost leak tester, or know how to do it.

And havent been able to find the thread on the quick way to go to ttc, anyone have the link?
Turbo, looks like a snail to me! (profile?)
 

·
GO 'Cats!
Joined
·
1,001 Posts
Look in the tech section or on mkiv.com for TTC quick and reversible method. Also, same place for boost leak.
 

·
Registered
Joined
·
1,848 Posts
Jeremy from speedforsale.com also sells a TTC kit that you can activate/deactivate with the touch of a button. Refresh the main page here a few times, you'll see the ad come by.
 

·
Registered
Joined
·
2,437 Posts
Discussion Starter · #7 ·
cherzra said:
Jeremy from speedforsale.com also sells a TTC kit that you can activate/deactivate with the touch of a button. Refresh the main page here a few times, you'll see the ad come by.

I have seen the TTC kit, but I can make the same thing for alot less cash and in alot less time. Ill go temp ttc and see if I like the powerband, if I do ill make the ettc switch/wiring

Both turbos have less than 6k miles on them of stock boost (aside from an extra psi or 2 from the downpipe.)
 

·
Registered
Joined
·
2,437 Posts
Discussion Starter · #8 ·
Dont I remember some really easy way go temp ttc without buying anything? All I remember is something got a vaccume cap put on it, which I know isnt helpful.
 

·
2jz powered
Joined
·
1,688 Posts
First thing you need to figure out is how much your boosting. You should hook up that gauge of yours. Then you can see if your actually boosting enough to cause fuel cut.
 

·
Banned
Joined
·
397 Posts
SoarerTT said:
First thing you need to figure out is how much your boosting. You should hook up that gauge of yours. Then you can see if your actually boosting enough to cause fuel cut.
Probably what's happening. Not even boosting enough to CAUSE fuel cut.
 

·
Registered
Joined
·
618 Posts
twistedmethod333 said:
Plus it seems like I loose too much power/torque at anything over 4500-5k rpm.
Wouldn't this indicate that the second turbo is not boosting properly?

On a long shot....you dont happen to have a boost cut controller installed on the car, do you? Ha ha.
 

·
Registered
Joined
·
2,437 Posts
Discussion Starter · #12 ·
chupacabra said:
Wouldn't this indicate that the second turbo is not boosting properly?

On a long shot....you dont happen to have a boost cut controller installed on the car, do you? Ha ha.

I checked that soon after I got the car and was thinking about going BPU, no bcc.

If the second turbo isnt boosting properly it is due to something in the sequential system, because the turbo itself is new.

Ill do a boost leak test after I get rid of this fever.

Anyone remember that other way to do the ttc?
 

·
Registered
Joined
·
934 Posts
SoarerTT said:
First thing you need to figure out is how much your boosting. You should hook up that gauge of yours. Then you can see if your actually boosting enough to cause fuel cut.
as soarer said, you are a nut for even trying to mess w/ boost without a boost gauge. thats like driving without a working fuel gauge and hoping you can fill it up every 3 days... LOL

do u REALLY want to fly blind? u have no way of knowing if your holding boost, if your overboosting, if your getting ANY boost.... PLEASE do urself a favor and get ur boost gauge working first.
 

·
Registered
Joined
·
2,437 Posts
Discussion Starter · #14 ·
mifesto said:
as soarer said, you are a nut for even trying to mess w/ boost without a boost gauge. thats like driving without a working fuel gauge and hoping you can fill it up every 3 days... LOL

do u REALLY want to fly blind? u have no way of knowing if your holding boost, if your overboosting, if your getting ANY boost.... PLEASE do urself a favor and get ur boost gauge working first.

Trust me, I am. THe previous theory was "im fine since im not hitting boost cut', but since thats not really viable any more I am going to go ahead and get the gauge working. It is $120 for a replacement greddy pressure sensor ! I started a thread in the parts subsection asking about nordskog gauges, Ill be getting a variety of those if they check out, and their complete boost gauge is cheaper than just the pressure sensor from greddy (if greddy USA even has it in stock).
 

·
Registered
Joined
·
1,602 Posts
The assumption that anyone, regardless of turbo or seq. system condition, who installs a DP is going to hit boost cut is incorrect .
 

·
Registered
Joined
·
2,437 Posts
Discussion Starter · #16 ·
MtFujiSupra said:
The assumption that anyone, regardless of turbo or seq. system condition, who installs a DP is going to hit boost cut is incorrect .

That is what I have always said when people insist that boost will spike like hell and hit the cut without the cats.

But, with the OEM catback, rmm downpipe, and bleeder t mod ( traditional 15psi (appx) version) I am still not hitting feul cut, nor did I feel a dramatic change in power with the bleeder T mod. Its my impression that the second turbo should be hitting much harder.

I was hoping you would get in on this, was about to send a PM. Anyway, the plan is to do a boost leak test this weekend. Im planning on plugging up the intake with a soup can, and pressurinzing the system to 10psi with a electric tire pump via a stem valve. Cant remember which hose the stem valve goes in tho.
 

·
Registered
Joined
·
13,581 Posts
I'm sure there are a lot of variables with the stock turbo system including condition of turbos, wastegate, etc but as a reference point, almost 6 years ago for my first mods I had the stock exhaust with a RMM dp and no other mods and I hit boost cut several times when I hammered it off the line, if I recall boost cut hit me as soon as the motor loaded in second gear. So I added the BCC, boost gauge and then the bleeder tee mods and it made a very big difference since boost was then up to 17psi on 94oct. But I eventually learned my stock setup was in pretty good condition proven by hitting over 25psi a couple times on high test and ebc set to 100%/100% which pretty much locked the wastegate closed.
 

·
Banned
Joined
·
378 Posts
Same here ^^^^ I am on stock boost in swapped SC and hit boost cut with 3" DP and 3" exhaust. Happends in lower gears only, running 12PSI. Boost comes on too quickly in 1st and 2nd....3rd and 4th and 5th I dont hit the boost cut.
 

·
Old School
Joined
·
4,126 Posts
Stringer Bell said:
Same here ^^^^ I am on stock boost in swapped SC and hit boost cut with 3" DP and 3" exhaust. Happends in lower gears only, running 12PSI. Boost comes on too quickly in 1st and 2nd....3rd and 4th and 5th I dont hit the boost cut.
That makes no sense, as one of the parameters for fuel cut is the time (>2 seconds) at >20% throttle above ~13.75 psi.

You'd be much more likely to hit fuel cut in the higher gears than the lower. Sure you are not tagging the rev limiter?
 

·
Registered
Joined
·
2,437 Posts
Discussion Starter · #20 ·
Im doing a boost leak test on saturday, which hopefully will find something easy to fix.

Concidering the turbos are new, I dont know what could be causing it. I doubt actuators and wastegate are reaplces when new turbos are ordered, maybe thats the problem.
 
1 - 20 of 107 Posts
Top