, LT headers (if not already done)
l98 - What next for more power?
Thread Starter
Burning Brakes
Joined: Aug 2006
Posts: 878
Likes: 2
From: BC
l98 - What next for more power?
Hi all,
being in the UK makes this a bit more akward than it is for some of you guys so I'm trying my best with whats availible...
I don't have a lot of spare cash each month so I'm looking for "little mods" that I can do a bit each month and that'll make a noticeable difference overall.
I know I could wait and save, but I get bored and need to tinker!
Motor so far -
1984 Block (Xfire) with Stock Forged Pistons (Bottom end bearings replaced)
1987 Alloy Heads (128?) on Felpro 1010's
Compression ~ 10.8:1
Summit 262/272 Flat Tappet Cam Link
1986 TPI intake system
1992 7730 ECM (Map sensor) with Super8D tune
1992 Injectors
No AIR injection or EGR
No Cats and Muffler Elim's
Running through an TH700r4 Auto4 built with Alto frictions and uprated sun gear.
Quickest 1/4 drag time so far
14.01 @ 98mph
Where do I go next?
Roller Rockers?
Ported TPI? (BBK Intake looks promising!)
LT1 Intake conversion?
Headers? (Are the "Cheap" ones OK?)
More aggresive Cam?
Cat-Back? (is an LT1 Exhaust an upgrade?)
Any other suggestions?
Car is not my DD so I can sacrafice drivability if needs be!
being in the UK makes this a bit more akward than it is for some of you guys so I'm trying my best with whats availible...
I don't have a lot of spare cash each month so I'm looking for "little mods" that I can do a bit each month and that'll make a noticeable difference overall.
I know I could wait and save, but I get bored and need to tinker!
Motor so far -
1984 Block (Xfire) with Stock Forged Pistons (Bottom end bearings replaced)
1987 Alloy Heads (128?) on Felpro 1010's
Compression ~ 10.8:1
Summit 262/272 Flat Tappet Cam Link
1986 TPI intake system
1992 7730 ECM (Map sensor) with Super8D tune
1992 Injectors
No AIR injection or EGR
No Cats and Muffler Elim's
Running through an TH700r4 Auto4 built with Alto frictions and uprated sun gear.
Quickest 1/4 drag time so far
14.01 @ 98mph
Where do I go next?
Roller Rockers?
Ported TPI? (BBK Intake looks promising!)
LT1 Intake conversion?
Headers? (Are the "Cheap" ones OK?)
More aggresive Cam?
Cat-Back? (is an LT1 Exhaust an upgrade?)
Any other suggestions?
Car is not my DD so I can sacrafice drivability if needs be!
Pro
Joined: Jun 2007
Posts: 577
Likes: 0
From: the best car on earth ,vettes are best
hello dan_t,
how are ya.
if you want to do a free mod or two, how about if you havent already remove the heavy disk known as the " frisbee" of the front of the water pump to remove a little extra drag.
then there is of course the other free mod, the throttle body bypass mod that deletes the radiator coolent going to the throttle body.
but in england " the mother country" being cold as it is may not be suited there.
just a couple of thoughts for you any way!
regards
shae
how are ya.
if you want to do a free mod or two, how about if you havent already remove the heavy disk known as the " frisbee" of the front of the water pump to remove a little extra drag.
then there is of course the other free mod, the throttle body bypass mod that deletes the radiator coolent going to the throttle body.
but in england " the mother country" being cold as it is may not be suited there.
just a couple of thoughts for you any way!
regards
shae
Le Mans Master
Joined: Jun 2006
Posts: 5,642
Likes: 5
From: One day you're a Comet...the next day you're dust... Arkansas
Intake will help without going back into the engine. More aggressive cam will give you the biggest pop. Wait and do cam RR's and upgrade springs at the same time. If by cheap headers you mean shorties, NO.
Thread Starter
Burning Brakes
Joined: Aug 2006
Posts: 878
Likes: 2
From: BC
with regard LT1/Miniram type setups...
are they a gain gain mod? I've heard that you may gain some hear but loose some there. Also that the mini ram may not work well with my Auto due to the change RPM's?
are they a gain gain mod? I've heard that you may gain some hear but loose some there. Also that the mini ram may not work well with my Auto due to the change RPM's?
Pro
Joined: Jun 2007
Posts: 577
Likes: 0
From: the best car on earth ,vettes are best
well the cheapest shipping to over seas from usa is " usps" united states postal services!
you save about 30-40% getting stuffed shipped with them say over fed ex, ups,bax global,ect!
secondly see how much your locoal customs allows goods $ amount up too, then get supllier of goods to write on customs form so that the amount is under the amount alllowed before you have to pay taxes,customs/duty fees!
regards
shae
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Le Mans Master
Joined: Jun 2006
Posts: 5,642
Likes: 5
From: One day you're a Comet...the next day you're dust... Arkansas
Racer
Joined: Dec 2004
Posts: 470
Likes: 0
From: Phoenix Arizona
350ci / L98's do not breath well (poor lungs) as senior members of this forum have pointed out. Headers are probably tied for first place with the stock TPI for disabling power. I've changed the headers and exhaust first and noticed a big performance / response difference immediatly. The top part (TPI) has many variables from the Super Ram, Mini Ram, to the Holley Stealth Ram all of which are pricey IMO. I suggest you continue to search this forum and ask questions then make you own decision.
Hope this helps
Hope this helps
Melting Slicks
Joined: Feb 2004
Posts: 3,307
Likes: 111
From: Tucson AZ
Dan T,
I spent 3 years at Upper Heyford. Raced at Santa Pod. Still have lots of friends there.
I will get bashed, but I think the best bang for the buck has been the rear end gears. I replaced the stock 3.07 with a 3.75 Richmond Performance gear set. Around town performance is fantastic and it actually picked up the 1/4 mile times more than any other mod I have done.
The only problem is the stock auto trans rear end is a Dana 36 and it is notoriously weak. A Dana 44 out of a manual trans car is the preferred path, but can be expensive.
Regards,
Vito
I spent 3 years at Upper Heyford. Raced at Santa Pod. Still have lots of friends there.
I will get bashed, but I think the best bang for the buck has been the rear end gears. I replaced the stock 3.07 with a 3.75 Richmond Performance gear set. Around town performance is fantastic and it actually picked up the 1/4 mile times more than any other mod I have done.
The only problem is the stock auto trans rear end is a Dana 36 and it is notoriously weak. A Dana 44 out of a manual trans car is the preferred path, but can be expensive.
Regards,
Vito
Safety Car
Joined: Feb 2000
Posts: 4,564
Likes: 110
From: Austin Texas
They can order the stuff for you, not pay any tax and MIGHT get it shipped cheaper as it goes to an APO address.
Drink an Abbot Ale for me...too hard to find back here.
Pro
Joined: Apr 2005
Posts: 590
Likes: 0
From: Boynton Beach, FL
If you want some tips for mods on the cheap, heres a few;
1) Pull the TPI plenum and remove the rectangular obstruction behind the throttle body blades. Its there to help the EGR port flow but It restricts air flow into the engine.
2) While your filing down the aluminum obstruction lay a gasket on the plenum mouth and scribe the port outline. Grind the openings up to be larger than the scribe lines and radius the entry.
3) After you've finished with the entrance lay plenum gaskets on the ports from the plenum to the runners and scribe the outlines. Open the ports to the scribe lines and then grind and radius the port entrances for a smooth transition into the runners.
4) Pull the stock exhaust manifolds and remove the heat shields. You will see that the welds from the flange to the pipes is on the inside of the pipe restricting the flow. Get out your grinder and remove the weld blocking the flow and radius the entry into the pipes. You can add a few tack welds to the outside of the pipe flange interfaces if your concerned about weakening the welds.
FYI I did all of these mods on my 86 L-98 and they worked fine.
Good luck mate.
Larry
1) Pull the TPI plenum and remove the rectangular obstruction behind the throttle body blades. Its there to help the EGR port flow but It restricts air flow into the engine.
2) While your filing down the aluminum obstruction lay a gasket on the plenum mouth and scribe the port outline. Grind the openings up to be larger than the scribe lines and radius the entry.
3) After you've finished with the entrance lay plenum gaskets on the ports from the plenum to the runners and scribe the outlines. Open the ports to the scribe lines and then grind and radius the port entrances for a smooth transition into the runners.
4) Pull the stock exhaust manifolds and remove the heat shields. You will see that the welds from the flange to the pipes is on the inside of the pipe restricting the flow. Get out your grinder and remove the weld blocking the flow and radius the entry into the pipes. You can add a few tack welds to the outside of the pipe flange interfaces if your concerned about weakening the welds.
FYI I did all of these mods on my 86 L-98 and they worked fine.
Good luck mate.
Larry
Thread Starter
Burning Brakes
Joined: Aug 2006
Posts: 878
Likes: 2
From: BC
If you want some tips for mods on the cheap, heres a few;
1) Pull the TPI plenum and remove the rectangular obstruction behind the throttle body blades. Its there to help the EGR port flow but It restricts air flow into the engine.
2) While your filing down the aluminum obstruction lay a gasket on the plenum mouth and scribe the port outline. Grind the openings up to be larger than the scribe lines and radius the entry.
3) After you've finished with the entrance lay plenum gaskets on the ports from the plenum to the runners and scribe the outlines. Open the ports to the scribe lines and then grind and radius the port entrances for a smooth transition into the runners.
4) Pull the stock exhaust manifolds and remove the heat shields. You will see that the welds from the flange to the pipes is on the inside of the pipe restricting the flow. Get out your grinder and remove the weld blocking the flow and radius the entry into the pipes. You can add a few tack welds to the outside of the pipe flange interfaces if your concerned about weakening the welds.
FYI I did all of these mods on my 86 L-98 and they worked fine.
Good luck mate.
Larry
1) Pull the TPI plenum and remove the rectangular obstruction behind the throttle body blades. Its there to help the EGR port flow but It restricts air flow into the engine.
2) While your filing down the aluminum obstruction lay a gasket on the plenum mouth and scribe the port outline. Grind the openings up to be larger than the scribe lines and radius the entry.
3) After you've finished with the entrance lay plenum gaskets on the ports from the plenum to the runners and scribe the outlines. Open the ports to the scribe lines and then grind and radius the port entrances for a smooth transition into the runners.
4) Pull the stock exhaust manifolds and remove the heat shields. You will see that the welds from the flange to the pipes is on the inside of the pipe restricting the flow. Get out your grinder and remove the weld blocking the flow and radius the entry into the pipes. You can add a few tack welds to the outside of the pipe flange interfaces if your concerned about weakening the welds.
FYI I did all of these mods on my 86 L-98 and they worked fine.
Good luck mate.
Larry
Any noticable differences from the porting?
Pro
Joined: Apr 2005
Posts: 590
Likes: 0
From: Boynton Beach, FL
None that I could quantify. Performance gains short of cams, heads and headers come in small steps. I know the intake flowed better with the mods but how much, your guess is as good as mine. For the price I couldn't complain.
Larry
Larry
Thread Starter
Burning Brakes
Joined: Aug 2006
Posts: 878
Likes: 2
From: BC
Thread Starter
Burning Brakes
Joined: Aug 2006
Posts: 878
Likes: 2
From: BC
I guess any improvement is an improvement!! will look into it!
