waddisme

After missing third track day yesterday due to FAST issues, I need to replace mine. It is a 90mm but the C6 mod keeps coming loose or leaking and I can't get it to idle for daily driving, or stay out of "Reduced Engine Power" at track. Don't really want to put another used FAST on. Motor is an aluminum 402 with MS3 cam, Patriot Stage 3 heads, Vararam, FLP headers, 42# inj. Car is actually a C5, so new 102 FAST doesn't seem feasible. What little I have read here on LS2 intakes doesn't sound very efficient. Are there any other options? Thanks for the input.

Fore58

The ported LS2 intake on my 05 C6 made 18 additional hp after the retune.

c6 batmobile

You can use a ported ls6 intake which are pretty good or buy a new unmodified fast. From what I understand the 90's were supposed to fit the c5s without modification. Im not sure if thats true but that is what I was told.

LS1LT1

That's what's confusing me a little bit here as well, I'm assuming that he bought the FAST used with the 'C6 firewall mod' already done to the intake? C5s shouldn't need that done.
If that's the case then just get another used 90mm or 92mm without that rear modification done to it.
A properly ported LS2 manifold is a good option as well but personally I would NEVER give up my FAST 92mm.

LSCHLEM

That Aluminum 402 is too rich of a Engine to deprive it of a Good intake Manifold. Check with Joe G. I think he got it right on finding a graft that
will hold up then you can use the FAST90. Or sell it and get a 102 Ported
by jeremy Formato. Either option will work and get you back in business.

waddisme

Actually I bought the intake used but did not know it had the C6 mod. I have had the C6 mod fixed twice and it still leaks. If I can find a new 92, then I will go that route. The ported LS2 sounds promising.

waddisme

I would like to do the 102, but it is a lot of work getting them to fit a C5. Trying to find a new 92 now. Were you the one who had issues with the FASTs leaking? Seems like I read one of your threads and you came up with a way to test them before installing. I just had my C6 mod fixed by one of the most reputable guys here and it is still leaking (throwing 1214 code). Even if I get a new one, I would not want to sell the old one without know if it was good or not. Can you test it?

LSCHLEM

Yes I did develop a rig that I can test the Manifold under Vacuum on a bench. The only thing you cant test is the port seals once on the Car.
Is your 90/92 Ported ? I know I got a 102 and had all kinds of problems & sent it back and Comp gave me a new one. I had that Ported by Jeremy F.
and it works flawlessly and outproduced my Ported 92 which I still have
sitting in my garage. I will have to look and see what the 1214 Code is.

waddisme

Intake was ported by Vengeance Racing. I mistyped the code, as it was P1514 that sent motor into "Red Engine Power". Interested in selling the 92? Or I could trade you a ported, sanded and painted 90 that looks nice but don't run worth a crap. Here is what it looks like:

[IMG][/IMG]

LSCHLEM

If you have a Leak the code PO171 & 174 indicates a lean condition. The other code has nothing to do with the Manifold leaking. It looks like you have the Manifold off the Car ?. If per chance its on the car and you have a scanner hook it up and monitor your LTFT's with the engine warmed up and idling. The Trims should be less than 10. Another quick check is with
a Vac gauge looking for 18+" of VAC.

waddisme

Actually those are the codes I was getting. I was resetting while on the track so I could get back to pits without getting run over. I do not have a scanner, but intake is still on car. I will get vac guage and check. Thanks for help.

SpinMonster

Code 1514 is airflow correlation. That has to do with running a 90mm TB on your car. Its a correlation of airflow and isnt a leak from your manifold. I think you need to verify you in fact have a leak at the manifold. If you find it isnt a leak (likely not a leak) the tune needs to be tweaked to make the airflow right to not go into reduced engine power. Fixing the tune requires you to adjust the airlfow tables to be higher---go to engine diagnostics then click on GENERAL---then click on the 1514/0068 airflow tab.

To see if you have an airflow leak, you would see really high long term fuel trends and thats a different set of codes like P0171 and 0174 which are system lean bank 1 and 2. You can get those codes from being 24% lean and not have a leak. A true leak from the intake will read +50 (pinned).

It doesnt sound like you have a leak. If you do and need a repair, I will do it for free. If you want the new FAST 102, I can get it to you for less and port it for free to help you out.

waddisme

I am probably confused about the codes, as I was clearing them while going down the backstretch. I have 4 track days this year with zero issues until the the mod started coming loose, so I feel confident in the tune and tb etc. My other vehicle at home is down, so I need to drive the Z for a little while, but, then I will take intake off and look at mod part. I ripped on it all last week to make sure it would be OK at track and nothing. First hot lap at track and boom - "Red Eng Power". Thanks for the help guys.

Justasheet

Wow, what a stand up guy you are Spin. You are a man amongst men.

Jeff

waddisme

As frustrating as this is, I am glad he is on the case.

Bill Curlee

SPIN is the man!

SpinMonster

Yeah what he said.

I think he has a tuning issue.

waddisme

OK - on way home today, I got it to go into "REP" twice. The actual code is 1516! TAC sensor issue. Just for the record, last year when the C6 mod was coming loose, I was getting this code and tuner switched TBs and and could not recreate code on dyno. C6 mod completely came off at next track day. I still find it hard to believe the tune is off as the car has been run hard at the 4 previous track days (150+ for 7-9 laps, 4 to 5 times per day) with no issues until C6 mod repair came loose, which should be fixed now. When engine cools down, I will do all the TB tests. Not sure what I am hoping to find. It would be cheaper to repl TB as there are not a lot of 92mm FASTs around. I will post what I find. Thanks guys.

LSCHLEM

The Mod "Firewall" if installed properly should not be coming off. Mine has been on for 2 years and never had any problems with the Manifold. My
manifold is a original 90 that was ported to 92-94 MM. I did the "MOD"
myself and shipped it out to Jeremy F. for Porting. Performed well until
I took it off. Now it sits on the bench but does not have the shine that yours does or was done by Vengance. Was your 92 already ported when you got it ? What are your plans for it ?

waddisme

It was already ported by Vengeance when I got it, as was the C6 mod. I just did not know the mod had been done. If I can get it to work without costing me any more track days, I would like to keep it. I have almost $2000 in it already. I paid $800 plus my LS6 intake (~$300), $400 tow bill from track for first time mod fell out, $285 for new bottom plate as old one had too many cracks, and $165 for second mod repair plus over $100 shipping to Vengeance etc. As it stands now, I am trying to find a 92mm, ported or unported, and put that on and then sell this one. I don't really care about the sanded polished painted thing because I don't street race, so stealth thing means nothing to me.

I looked at Spin's mod repair with just a mirror and it looks fine so I am really confused now. TB appears to be hooked up fine and blade seems to be moving correctly with nothing caught in there. Going to do some resistance testing if I can figure that out. If you are doing nothing with yours, would you be interested in renting it out for a day? I will pay for shipping and insurance. That would eliminate intake from equation or expose it. Just a thought.