tomz28

iTrader: (20)

he guys with aps cars with 400+ CI how much boost are you running/ can you make with the frist F-body TT kit im runnig a stock bottom end ls1 at 12 psi right now. i got a meth kit, LPE 2-step, and a e-boost2 i need to put on yet
i was thinking of having a LS2 364ci made for it. with some L92 CNC and turning the boost up to 16 to 20 psi and maybe a 100 shot just to get things moving when i have my slicks on at the track.
i have heard that 402 and 408 have some wear issuse with piston but not all engine are the same wiith that kind of thing
this is a street car for the most part and i know the 402 will make good power. the car is a M6
i want about 850 wheel it all ready makes 650rwhp
so my ? is will the turbos make the boost i want to feed the 364 and/or 402
so just give me your two cents thanks guys

MY99TAWS6

iTrader: (3)

That post was a bit hard to follow Tom. I can see zero reason to go down to smaller if you already have a 402. Jm is running 9s at 140 with his 402 and the original kit. At 12psi . With 4.10 gears. APS ran their smaller engine 346 forged car to like the power level you are trying for. And like 20psi.

Now that said not sure we can get 20psi easily with a 402 or 408 but not sure you should have to. I would think 850rwhp is still possibley on a 402 or 408 m6 car with the smaller turbos at maybe 15 to 18psi depending on mods. Not necessarily on pump though. More likely will take e85 or race or meth injection . Someone still needs to try it.Course the tubes are closing so we need someone to try it with the revised tubes or no tubes or air cleaners just right on the turbos at the dyno.
You could of course just upgrade to the bigger turbos but not sure what they are doing if your turbos have already been run. I could trade up still as mine are still in the box.
Stilll thinking about it but really would be happy if it runs anything in the 10s and past 130mph that is plenty for a street car. I have zex kit that can install also if came up a bit short on my hp goals.

Smaller turbos will spool up quicker and should give a more street friendly power band. If they are full spool at 3000 for example that is a nice 3000 to 7000 power band. If the bigger ones spool up at 4000 then your power band gets narrower not that great on the street.

Ran into this on my 97 talon. Have a big Garret on it. It full spools around 3800 on a 2.4 engine. Now you get a powerband from near 4000 to 8000. Not great. I use two step and have anitlag to get off quick when you are racing it type of thing.But you would not want to use antilag or two step all the time. I can also gear down to get it spooled quicker when you are in higher gear but going up thru the gears normally it can be doggy until boost happens.

So might downsize a bit on that car to make it better street car. And put that big turbo on my race talon.

I was hoping to be running in spring but things just didn't work out for me. I finally have my 408 sitting here but now running out of time to get it in the car and running before season ends.And that don't mean track season just season in general my car goes away nov 1 latest.It gets nasty quick up here in Canada past that.

Anyway we need some guys to push those smaller aps turbos on a 402 or 408 to like 15 to 20psi and see just what happens to power numbers.
I expect to see power not doing much past 15psi but if they can hit 800 or 850 rwhp at 15 on the bigger engines even on race or e85 good enough for me or within maybe 50 to 75 hp. Can make them up with small shots of spray. And the spray spools up the turbos very very quickly.
Spray and turbos can play together.

As far as worrying about longevity with a 402 or 408 I wouldn't. I am sure you can get a good 100,000 miles out of one no problems if you have tune right and nothing really strange happens..oil pump failure,etc.

I will for sure be dynoing it a few times at various boost levels and tracking it a few times. Not sure about rollbar at this time don't plan on one.So once it gets past 11.5 its track days will likely be over but we do have a slack track that maybe can get much faster runs on. They are not nhra so they can't really kick you like NHRA tracks do.Might be an option.

Tom@SpeedInc

iTrader: (5)

I have a 402.... run 7psi and done so for 30,000 miles.

We just completed a customers Fbody APS build with larger turbos and 403ci/TH400
18psi boost made 809rwhp

so yes defiantly 403 cubes is good idea

Let me know if you looking for an engine, the 403ci shortblock build we combined with the APS turbos to make 809rwhp runs $4179

tomz28

iTrader: (20)

thanks that helps alot and sorry for the post i can drift off some times LOL
fraser can we see the specs on that 403 thanks

Tom@SpeedInc

iTrader: (5)

Using Iron 6.0 block we combined this with

Callies Compstar crankshaft
Compstar H beams
Clevite H series bearings
Wiseco 4.005" -20cc pistons w/ plasma moly rings
ARP main studs
Full balanced, align honed, and deck plate honed bores


base price $3999
add m/stud kit +179


same build was featured in GMHTP pg 46 last month

bca21

can you send me a pm, looking at short block as we speak. Looking at low compressin, 400+ ci 1000hp capable. Lets talk

Sorry for hi jack

tomz28

iTrader: (20)

i want to use a LS2 block trying to save some LBS.

MY99TAWS6

iTrader: (3)

Think read 65 pounds heavier with the iron block. I wanted max strength power from turbos more than make up for a few extra pounds. Personal choice of course.

tomz28

iTrader: (20)

if i was going over 900 or 1000 wheel than yes i would go iron but a LS2 block is good for this. i think its more than 65 pounds
someone feel free to add to this but i was thinking more like 80LBS+
thanks my99taws6 for yor two cents always good to read your page long posts bro LOL

WARPNOVA

iTrader: (3)

I too have wondered about running the larger engine on the stock size turbos and as things come next April I maybe able to afford the larger engine. My goals are to be as street friendly as possible and still make I hope 700+ rwhp. The larger engine I feel would do this best unlike a small engine with low compression I am afraid it would end up being too doggy out of boost. I want something that dives almost stock with plenty of torque and power out of boost and then turns into a mean mother when you put the boost to it.

Fraser was that build you speak of on the stock or small size turbos or the new stage two turbos. I believe it was the smaller ones but just checking. Also is that price you have quoted still available as Speed Inc is included in my small list of two places to buy my motor from and although I am not ready, yet I wanted to get a fair idea of just how much it will cost from your shop.

Oh and tomz28 I too have wondered about the use of iron vs. aluminum and yes weight and strength are a huge concern for me. From my reading, I have concluded that yes, Iron is stronger, heavier, and some say more difficult to cool. It is also cheaper and only about from what I understand about 65 to 70 pounds heavier. Sounds like a lot but then I remembered that the APS kit does require an aftermarket k-member. The one I have is a UMI and is advertised to be at least 25 pounds lighter then stock and if you are running the BMR, it is even lighter. So if you look at it this way you are only adding about 40 to 45 pounds over stock weight with the UMI k-member and iron block. Yes the turbo kit does add weight on it’s own but that is unavoidable and I believe someone guessed about a 100 or so pounds.

What it comes down to at least for me is cost as the LS2 will also require the wiring harness extensions for the knock and map sensors and not to mention the different front and valley cover and maybe the rear cover but I think you can use the stock ls1 rear cover on that part. All in all the LS2 adds up to the cost real quick. I like the aluminum block for weight and strength. I do not feel strength is a problem for me either has 800 crank horsepower is about all give or take a little that I am looking at. However, I have also read that 800 horsepower is about the kick over point to go ahead and run a different block such as the iron block.

More thoughts and that is the new LSX block actually weights more then the iron block, which sort of surprised me but considering how thick and well built they are it makes since. Anyway, for as many people adding them to their builds now I don’t see there being a big draw back to running the iron block as it does provide a little more strength and helps save money for maybe a nicer set of heads and or what not.

If I am wrong or off on anything let me, know because I am trying to learn and figure things out as well.

tomz28

iTrader: (20)

thanks man i like to hear any thing about what poeple are doing more the better
and i think that car speed inc did was a stage two they hant said any more about it

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Damn Fraser, I didn't realize you had that many miles on it. You're long overdue for a clutch/boost controller.