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View Full Version : how to get my turbo to spoll faster



95turbocharged
10-26-2007, 10:17 PM
I have a stock 302 long block,
holley systemax intake
70 trim turbo
96 exhust housing
48 mm wastegate
50mm blowoff
c4 tranny
alum driveshaft
here is the issue, I was running a 373 gear and a tko 600 with a spec stage 3 clutch the turbo was comining into boost @ 2800 rpm and in full boost @ 3500 rpms but I had turbo lag between shifts. I then switched to a c4 tranny and my rpms were to high to drive on the highway so I was told to switch my 373's to a higher gear and that would make my car come into full boost sooner and it would be better on the highway. So i made the switch to a 327 gear and the car is about 3-4 tenths faster than before but my turbo is now comning in to boost and at full boost about 7-800 rpms later than before. well I guess what i am trying to find out is how to get the boost to come in earlier with this setup. I dont want to go back with the 373's is there another way to get the boost back without changing gears?:confused:
this whole setup is doing the oppisite of what everyone thought so I am kinda lost as to what to do.

347sc
10-26-2007, 10:24 PM
Switch to a smaller a/r on the ex housing.

95turbocharged
10-26-2007, 11:15 PM
what do you mean a/r?

347sc
10-26-2007, 11:22 PM
The housing on a turbo have a rating called A/R It is a measurement of area in relation to the inlet and outlet of that housing.
In short the housing has a number cast in it.
a .64 will spool faster then a .96.

95turbocharged
10-26-2007, 11:36 PM
oh I thought that was it. I had a .68 on it before and blew up 2 motors thats why I went with the .96 what do you think a bigger set of heads would do?

bobtsgt
10-27-2007, 08:13 AM
the bigger the exhaust housing will help on launching the car. The turbo won't hit so fast to where you have a chance of spinning. Do you still have your smaller housing?

KenB
10-27-2007, 08:26 AM
I think you guys are leading him down the wrong path. If it spooled better with the 5 speed with the same turbo, you need to look at the converter.


KEn

bobtsgt
10-27-2007, 08:30 AM
good call Ken. Didn't see the auto part there.

95turbocharged
10-27-2007, 09:14 AM
I think you guys are leading him down the wrong path. If it spooled better with the 5 speed with the same turbo, you need to look at the converter.


KEn

cool, you are the forth person to tell me that! I think I have found one that will be perfect for my car :bigthumb

95turbocharged
10-27-2007, 09:21 AM
the bigger the exhaust housing will help on launching the car. The turbo won't hit so fast to where you have a chance of spinning. Do you still have your smaller housing?

I have a 2 step on the car and I lainch at 2800 with just foot break and I take out 9 degrees of timing to get 3 psi at launch. anything over 2800 and it pushes through. Transbreak is comning but for now I think my et's would be alot better if it spolled faster cause its hooking pretty good 1.59 6o ft.

347sc
10-27-2007, 10:59 AM
I didnt see that either.

Jeff88coupe
10-27-2007, 12:38 PM
Using a transbrake along with a 2 step will help. You should be making boost when you launch.

Timido
10-27-2007, 11:28 PM
I wonder how they use a 3 step on the big dog cars to build more boost

Dirtyd0g
10-28-2007, 12:34 AM
cool, you are the forth person to tell me that! I think I have found one that will be perfect for my car :bigthumb

Turbo's are very tricky on converter stall. When it's right it's deadly. You want some boost but not full boost on launch to prevent the lag. At full boost you'll blow through most cheap converters so it takes something strong.
I'm local and will gladly help you get it right. I can't promise it'll be the first try, because honestly turbos are complicated to really nail the stall. I can tell you I can get it right, once it is you'll know it.
Alan

plated
10-28-2007, 07:23 AM
i have a .68 a/r if u wanna try iy,with stock heads i'd go to a smaller a/r than the .96

89notch
10-28-2007, 09:09 AM
I also think the .96 on a stock longblock is a little much

ibstrokin
10-28-2007, 12:51 PM
Call Dave @ majestic turbo for an expert opinion. He was really helpful with the pinks car. My guess would be a little of both, smaller a/r, then custom convertor, but I am by no means a expert on turbo's.

WhiteT
10-28-2007, 04:43 PM
I have had my converter in and out of my car 5 times this year. Like what was said above, there is a fine line between too loose and too tight. Too tight and it's hard to spool, too loose and your slippage at the end of the track will hurt you. For an example, my car had a converter that had 20% slippage at the end of the track. It spooled lightning fast, but went 132 mph at 6300 rpms. Next attempt it had 8% slippage, hard as hell to spool, but went 137 at 6200 rpms. The converter as you can see is very important.
I'm still looking for that right number:)

95turbocharged
10-28-2007, 05:05 PM
Turbo's are very tricky on converter stall. When it's right it's deadly. You want some boost but not full boost on launch to prevent the lag. At full boost you'll blow through most cheap converters so it takes something strong.
I'm local and will gladly help you get it right. I can't promise it'll be the first try, because honestly turbos are complicated to really nail the stall. I can tell you I can get it right, once it is you'll know it.
Alan
I think I will pm you and we can exchange #'s and go over this!

RIXXX93GT
10-29-2007, 04:06 PM
I wonder how they use a 3 step on the big dog cars to build more boost

I believe they pull all the timing out when they stage (car back fires like crazy) and then when they launch whammo boost and timing all at once. Could be wrong but thats what I saw at BG.

atbracn
10-30-2007, 09:33 PM
call ptc and ask for tim he sold me a converter and i haven't had it out ones. i have a 306,76mm,81 a/r leaving off foot brake with 327 gear and i went 10.80 129 mph letting out but still only making 10lbs of boost.my care starts making boost at 3000 rpms.

95turbocharged
11-03-2007, 08:26 PM
well it looks like we found out why I am having spolling issues there is a crack in my drivers side header thats about 3-4 inches long we wont know how bad it really is until I unwrap my header so we'll see what it looks like tomorrow but, this the second time I have had this turbo kit crack on me. After talking to ken and jim we think it might be from the header wrap holding in to much heat. Just wondering if anyone else has had turbo kits crack from wrapping them?

Maximus
11-03-2007, 11:27 PM
Hijacking your thread......

YOUR STANG LOOKED SAAAAWEET rolling down the highway this afternoon!!:bigthumb

95turbocharged
11-04-2007, 12:24 PM
thanks:bigthumb