I need some help. I built my own turbo kit from a PT88 on a 402 LQ9.... and it SUCKS it only made 557 Rwhp on a mustang dyno at 10 psi....... I spent $40,000 trying to build an 8 second street car, and Im going to have to do something very different with the turbo kit but I dont know what my problem is!

I have 1 5/8 header primaries, and 2 1/2" collectors, and crossover pipes with a T4 flange PT88 and a 3" downpipe, the charge pipes are 2.5" I know these are horrible dimensions but what stuff do I need to make 1000 rwhp with this 402? I can boost up to 25 psi with it and I built it from the ground up as a turbo motor so it will easily handle the task.

Im thinking I should start from a set of header flanges, and a pile of stainless

1 3/4" primaries on the headers with 3" collectors and crossover, into a T6 flange, 5" downpipe, and like a turbonetics thumper 101.. then, 4" charge pipe all around ... and the biggest A2W I can fit..... Inside the car this time.

Should I go ahead with this? or stick to what I have, make a 4" DP, and 4" charge pipes and hope for the best?

 

WHAT timing?
what a/f ratio ?
what transmission?

don't throw it away mate....
sort it out... or get someone to look at it


cheers
ash

 

double or triple that 10psi

 

edit: just realized you had only 10lbs of boost. turn it up to 18lbs. add some timing. and some c-16 and you will be fine

 

i would see how far u could go with your current setup before i would change anything. u made good power for only 10 psi . I need 15 psi to get to your power level.

 

For starters mustang dyno 's read a little low?
Second if you are trying to make 1000rwhp, why did you stop at 10psi.??
It will take you appx. 20-25psi. to get 1000rwhp, depending on the setup. Your 10psi. rwhp I would not even be bothered with. Your setup is obviously not in its efficienty range yet, so the #'s will not be good until you get it there. Turn the boost up and see what happens. You will be surprised.The turbo may be a little small for the amount of power you are wanting to make ,maybe, you will get close though.
Also, 2.5 in. charge pipe is plenty. They run 7's with that size!

 

Im just totally pissed because me and my friend kyle built a stout N/A 408..... we raced on the "street" from 0 - 135 and he stuck with me the whole friggen way!!!! and I was running 14PSI today! only thing is my water pump for the A2W took a **** on me, so I think my intake temps were COOKING and all the timing got pulled out, it happened on the dyno and I lost 100 rwhp...... BUT ****.. hes N/A! I gave him a 300 shot kit and he hasnt even finished installing it yet.

 

Your current header size and charge pipe sizes are fine. Step up to a 4" DP. Turn the boost up. Let it eat.

What are you using to tune the car? Who is tunning the car?

It sounds like you are leaving alot on the table.

 

Yea I dont know a lot but the 3 inch downpipe sounds too small to me.

Could be a tune issue too.

 

The hardest part of any custom build is finishing dialing it in. It is not uncommon to have a couple wiring related problems, a few leaks, some fuel system tweaks and require you to learn a lot about methodical troubleshooting and tuning. It took me a year to get my build truly stabilized and running the way I expected it to.

Here's my advice, partially based on your specs above: stick with it. Gather lots of data - add a fuel and AFR gauges a friend can watch while you slowly add the boost and safely get comfortable with the tune. If you don't have a wideband O2 sensor, spring for it now, without it you are blind. Do not give in to the temptation to crank up the boost before you and it are ready - I suggest no more than 2psi increments at a time with lots of data logging. Don't try to watch the gauges yourself while under accel. It's bad news.

Jeff Hartman's book on Tuning and Modifying Engine Management Systems helped me a lot. Get the book for $20 or so on amazon.

I admire anyone that can put together a complex system like that and make it work reliably. Nothing in your numbers indicates you are set up for failure.

Now bring it on home!

Jim

My site: http://home.mindspring.com/~jim_fisk/id1.html

 

Do you still have the M6 in the car or have you changed to a TH400 or something like that? It makes a big difference on the dyno. I lose around 250 rwhp on the dyno compared to what I actually make at the wheels due to the trans/converter, just the nature of the beast.

Have you been to the track? What ET/MPH has it gone?

 

Do you have a dyno graph?

Make a 4" downpipe and I'm sure you will be surprised. You are going to have to turn up the boost to get close to your goal.

 

Still an M6... ran 7.70 1/8th mile with a disgusting 1.7 60' waiting for the boost to come on... (used to run 6.90s before this turbo nonsense) also I was consistantly battling high intake air temps which repeatedly pulled ignition timing and the old Greddy RS blow off valve was so small my turbo would go into vacuume after a shift!


I swapped out to a tial 50 MM BOV, and bought a piece of **** synergy motorsports 2 step which doesnt work right, but I know others have had great luck with them so its probably only mine, going to call on monday to have it repaired hopefully. Also my A2W water pump took a dump, so Im going to need a new one, and I need to move the A2W intercooler's heat exchanger off the radiator, I think the radiator is heating the damn thing up!

too bad I go to Iraq on january 2nd, so ill never get to "finish" this chapter of my car untill I get back. Ill swap to a 3 bar then, have my friend casey tune it on the dyno for the 25 PSI, and put a 4" DP on it... if that crap cant put me in at LEAST the 9s... Im selling the whole kit, would work killer on a 370 or smaller cube motor Im guessing

 

Don't give up on what you got. You have the parts for an 8 second ride at 150+ mph.

The 3" downpipe is a tad small, but it should be good for 8's.

The 2.5" charge piping is too small. Go with 3" here.

Up the boost to 17 or so psi and it should run.

BTW, a pt88 is good for 402 cid.

 

You have quite a few problems from what i see....... dont give up... u have alot of things holding you back.
Fix the water, pump and tuning..... those are the biggest things i can see...





On side note...... you will prob never see 25 psi with that kit.... its the downpipe and turbo size, mixed for your cubes.

Being 400+ cubes with a T4 flanged turbo with a 3" DP...... i see 21-22 psi max.... then after that if it does see 22+ psi u will start to lift the heads on a 4 bolt setup.

Is your buddy's N/A setup an M6 also??

Look at Mightey Mouses setup really close..... you have about 40 more cubes then him and the same Turbo.....

With a M6 his best was a 9.98....... now with the 4L80E....... 8.6X's he's maxed at 23psi....



Not putting you down any....... U just have quite a few things to work out 1st...... dont give up..... u will get there.


Kyle

 

not really.and your setup must be horribly inefficient to need 15psi to make 575rwhp.

to the OP.dont go throwing everything away until you get all the bugs sorted out.a 2 step will helpout quite a bit on launch so u can leave in boost.you need to stop and think logically about where your bottlenecks are and youll need to turn up the boost like everyone said to make the power youre looking for.dont give up!

 

I wouldn't be supprised if that setup made 575 hp with no timing. If the iat's and ect's were high like he said. really need to see a dyno and possibly a data log to see how much timing was thrown at it. Get some timing in there, get rid of the restrictive 3 inch dp. Sounds really small for that turbo, my gt4276 has a 4 inch dp, and 3 inch charge pipes.m New dp, Retuned with timing and 3 inch charge pipes, and you might be up 100hp.

I built my kit last winter. It works, but every time ive been to the track its working out a little problem. I expected it, and have still not made a good pass. It will come, just gota keep at it. In the end the potential is there to go so far with turbo, even though it would of been easier with motor and spray.

Chris

 

Like the majority said. Get it retuned and get your water pump fixed as well. As far as switching to a 3in. charge pipes, I would do that as well.

 

2.5 inch charge pipes?? are you thinking the hotside?

I thought most are runnign atleast 3 inch ic pipeing. Would kinda suck to do transitions into the ic, and turbo most turbos are atleast 3 inch on the charge side, and the tb is what 3.5 inches??

Chris

 

Yes, I am thinking hot side.
If the charge pipe is only 2.5in. then I agree make it a 3in.atleast. My bad, brain fart!