Low 408 results?
11-29-2008, 01:32 PM
#1
Staging Lane
Thread Starter
iTrader: (2)
Join Date: Jun 2008
Location: Fort Myers, FL
Posts: 83
Likes: 0
Received 0 Likes
on
0 Posts
Low 408 results? Car is a 98 TA M6 3.42 gears stock 10 bolt.
HKE 408
Probe Pistons
Stock 241 Heads Ported/Polished
Stock Compression
238/242 112+2 Custom Cam
Ls6 Intake
42lb injectors
Put down 440/435 on a dynojet.
Seems low for a 408.. any thoughts? Oh and rev limiter is 6600 they only brought it like 5800
HKE 408
Probe Pistons
Stock 241 Heads Ported/Polished
Stock Compression
238/242 112+2 Custom Cam
Ls6 Intake
42lb injectors
Put down 440/435 on a dynojet.
Seems low for a 408.. any thoughts? Oh and rev limiter is 6600 they only brought it like 5800
11-29-2008, 01:50 PM
#2
i saw 3 things in your 408 :
1- are your 241 heads realy flow good with high port velocity?
2- stock compression around 10:1 you should be 11:1 to 11.8:1 to make more power.
3- your cam is a little on the low side, it should be more like 244/248 to 248/254 or so.
1- are your 241 heads realy flow good with high port velocity?
2- stock compression around 10:1 you should be 11:1 to 11.8:1 to make more power.
3- your cam is a little on the low side, it should be more like 244/248 to 248/254 or so.
11-29-2008, 02:00 PM
#3
10 Second Club
iTrader: (2)
Join Date: Aug 2005
Location: Ottawa, IL
Posts: 956
Likes: 0
Received 0 Likes
on
0 Posts
I agree with Zaccagnini, you need to at least port your 241s, bump your compression up to around 11:1, change the can, and you could also ditch the LS6 intake for a FAST setup.
11-29-2008, 02:32 PM
#6
TECH Fanatic
Join Date: Aug 2005
Location: Sunny London, UK
Posts: 1,690
Likes: 0
Received 0 Likes
on
0 Posts
Yeah your heads and intake are holding you back. Probably mainly your intake and TB at present. Put the fast92/92 on and you should gain a good bit. Heads are probably 5-10% off the pace, but Im betting your intake and tb are the biggest bottle neck.
Trending Topics
11-29-2008, 04:35 PM
#8
11 Second Club
iTrader: (4)
Join Date: Aug 2004
Location: DFW
Posts: 470
Likes: 0
Received 0 Likes
on
0 Posts
I would do Fast 9X/9X and 1 7/8 headers (if you don't already have them) first and see where that puts you. If your power is still not where it should be I would look at a nice set of heads!
11-30-2008, 08:25 AM
#12
11 Second Club
iTrader: (14)
Join Date: May 2007
Location: Wisconsin
Posts: 709
Likes: 0
Received 0 Likes
on
0 Posts
i have very similar cam, and tsp ls6 stage 2.5 heads, with a fast 90/90 #s in sig. I just got some arh 1/78" long tubes to get ready for bigger heads and cam after next season. buying things slowly. I should jump to over 500rwhp with better heads, cam, exhaust. YOu are right on track with what you have now. The power is there uncork it when you get the money.
11-30-2008, 11:47 AM
#15
TECH Regular
Join Date: Mar 2006
Location: Rolesville, NC
Posts: 471
Likes: 0
Received 0 Likes
on
0 Posts
11-30-2008, 12:52 PM
#16
TECH Addict
Join Date: Jul 2002
Location: Somewhere I Belong
Posts: 2,906
Likes: 0
Received 0 Likes
on
0 Posts
12-01-2008, 10:41 PM
#19
TECH Fanatic
iTrader: (1)
Join Date: May 2004
Location: Mesa, Arizona
Posts: 1,691
Likes: 0
Received 0 Likes
on
0 Posts
A little bump in the compression (11:1 is a perfect mid point) by either changing head gaskets or swapping to a different cylinder head thats been milled would be a great starting point. I'd look into a "premium" set of cylinder heads if the money is available OR even a great "budget" head like TEA or ETP ported 243 castings if you're trying to save a little coin.
I'm sure that cam is just fine. There's no reason to try and stick a donkey dick cam in there. You'll just wind up being disappointed with the results. Also, there is NOTHING wrong with 1 3/4's on a 402/408 motor. Again, you'll go through all that hassle and spend all that time and money on nothing more than a "few" ponies upstairs and possibly negate all gains made by losing a **** load down low.
Heads and a little bump in compression. After that, see where you're at and then start considering the fast 90/90 or 92/92
I'm sure that cam is just fine. There's no reason to try and stick a donkey dick cam in there. You'll just wind up being disappointed with the results. Also, there is NOTHING wrong with 1 3/4's on a 402/408 motor. Again, you'll go through all that hassle and spend all that time and money on nothing more than a "few" ponies upstairs and possibly negate all gains made by losing a **** load down low.
Heads and a little bump in compression. After that, see where you're at and then start considering the fast 90/90 or 92/92
12-01-2008, 11:18 PM
#20
Banned
iTrader: (5)
Join Date: Apr 2003
Location: Chicago
Posts: 1,890
Likes: 0
Received 0 Likes
on
0 Posts
Thats about the same power my boost 402 was making pre turbos, 10.3:1 compression, stock Dart heads flow 300cfm, 236/242 cam, it made 451rwhp, so I put turbos on it and haven't looked back.
Those pistons must be dished? need more compression, cometic gaskets with tighter quench, depends on how those pistons setup, if they are at 0 deck, I would go with .040" gasket. Mill the heads down to 60cc.
and FAST intake
but pulls only went to 5800 or am I reading that wrong?
Those pistons must be dished? need more compression, cometic gaskets with tighter quench, depends on how those pistons setup, if they are at 0 deck, I would go with .040" gasket. Mill the heads down to 60cc.
and FAST intake
but pulls only went to 5800 or am I reading that wrong?
Last edited by Fraser@SpeedInc; 12-01-2008 at 11:24 PM.