Go Back   LS1TECH > SBC-BBC-LT1-LT4 PERFORMANCE > LT1-LT4 Modifications
Sign in using an external account
Register Forgot Password?
Search

LT1-LT4 Modifications
1993-97 Gen II Small Block V8

Welcome to LS1Tech.com!
Welcome to LS1Tech.com.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join LS1Tech.com today!


Reply
 
Thread Tools Search this Thread
Old 09-11-2013, 11:36 PM   #1
Teching In
Garage is empty, add now
 
Trader Rating: 0
Join Date: Sep 2013
Posts: 14
Default L31 shooting for 400whp. Need advice.

Hey guys, I'm no stranger to a small block, have had a few gen I's that made 500+, fuel injection is fairly new to me in terms of making power.

I've got a 98 S10 with an L31 swapped in from a 98 fullsize. It's got the elusive poppet valves and my cylinder 4 one may as well be pooched.

So here goes, I've got access to a very cheap, complete TPI. Through reading I have found they're not great at the top end, and I would be in an extra $400 buying the proper lower section for my Vortec motor. That, or am I able to run old style heads on this motor? Ideally, aluminum heads would be great to relieve some weight off the front of the old girl.

I've been searching around and think I like this cam:

http://www.summitracing.com/parts/cca-08-503-8

My question is, is the TPI setup worth spending the money on? I've found a few others for a LOT more money invested (GMPP ramjet, etc). If I can save some on the manifold setup, I have that much more to play around for cyl heads, etc.

Thanks in advance guys.
HooWybrow is offline   Reply With Quote
Old 09-12-2013, 07:31 AM   #2
TECH Fanatic
Garage is empty, add now
 
bowtienut's Avatar
 
Trader Rating: 0
Join Date: Mar 2007
Location: Bright, IN
Posts: 1,276
Default

You might find some better advice and examples at a place like this:
http://www.fullsizechevy.com/forum/g...n/performance/

Not a lot of experience with that motor on this forum, but I do have a little experience with the L31, so I'll offer this:
First, 400 whp means you won't have much left of an "L31". About the only thing I'd keep, with that target in mind, is the shortblock, and then you might as well start with any old SBC Gen 1 block.
Yes, the heads are excellent as far as iron heads go, but to take them from their ~250 whp baseline capability to what you want, your money would be better spent on aftermarket conventional Gen 1 aluminum heads and avoid the Vortec intake manifold limitations. so yes, old-style heads are the way to go if you're serious about that goal.
You're right about the stock injection needing to go, even if you were to stick with the L31 heads. Even the GM upgrade to the poppets will get you nowhere toward your goal.
And for 400 whp.....forget TPI. It's too much of an "rpm choke" to get you near 400 hp without ridiculous money and mods heaped upon it.
If your goal was more like 300 rwhp, then you could make it happen with the Vortec heads and modifications to the manifold. Check out the forum I linked above and search under vortecstroker screen name. The stock manifold quits about 5500 rpm, so figure 325whp as the limit with a 383, and 300 whp with a 350/355. That cam you linked would easily get you to those numbers, but may be a stretch for 400 whp.

Edit: There are also a few threads on this forum in the "Tech" and "Engine Swap" sections on L31 buildups:
http://www.thirdgen.org/techboard
__________________
1996 Impala SS
Stock shortblock, AI cam/heads
10.98 @ 122 on motor, 10.35 @ 128 on the 100-shot
2012 ISSCA Nationals SSuperPro Champion
2013 ISSCA Nationals SSuperNatural Champion
2013 ISSCA Nationals Roadrace RunnerUp
2014 ISSCA Nationals SSuperNatural RunnerUp
2014 ISSCA Nationals Autocross RunnerUp

Last edited by bowtienut; 09-12-2013 at 07:39 AM..
bowtienut is offline   Reply With Quote
Old 09-12-2013, 10:05 AM   #3
Launching!
Garage is empty, add now
 
HellTeeOne's Avatar
 
Trader Rating: 0
Join Date: Sep 2003
Location: Raleigh, NC
Posts: 228
Default

I'm taking a shot in the dark here as I'm not all that familiar with TPI stuff. But wouldn't a TPIS Miniram, a set of 30# injectors, 58mmTB, a good custom HR cam, a set of the best 200-215cc TFS or AFR Gen1 SBC castings ported by LE or AI, on top of a healthy shortblock with the requisite longtube headers and exhaust get him his number?

Of course, this assumes the compression ratio, PCM tuning, ignition, etc. is all in order and up to snuff.
__________________
Cayenne (Pepper) Red 1997 Z28 M6
-AI H/C/I, bolt-ons, Hooker LTs, stock shortblock, etc. 406/385-
HellTeeOne is offline   Reply With Quote
Old 09-12-2013, 10:14 AM   #4
TECH Fanatic
Garage is empty, add now
 
bowtienut's Avatar
 
Trader Rating: 0
Join Date: Mar 2007
Location: Bright, IN
Posts: 1,276
Default

Quote:
Originally Posted by HellTeeOne View Post
I'm taking a shot in the dark here as I'm not all that familiar with TPI stuff. But wouldn't a TPIS Miniram, a set of 30# injectors, 58mmTB, a good custom HR cam, a set of the best 200-215cc TFS or AFR Gen1 SBC castings ported by LE or AI, on top of a healthy shortblock with the requisite longtube headers and exhaust get him his number?.....
Yes, it would. Easily! It's either something along those lines, or lower his goal if he's retaining much of the L31 setup.
bowtienut is offline   Reply With Quote
Old 09-12-2013, 10:14 AM
LS1Tech
Pontiac Firebird




Paid Advertisement
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
New build help! Chi_weezy Generation IV External Engine 3 05-13-2013 10:48 PM
WTT: Turbocharged 87 Firebird for 98-02 TA kmfl Vehicle Classifieds 3 02-21-2013 08:39 AM
cammed 5.3 in 87 camaro. Take off issues 1987earthquake Conversions & Hybrids 19 08-15-2011 07:37 PM
ls3/t56 '89 IROC-Z jsacra Conversions & Hybrids 45 06-05-2011 09:47 PM
LT1 cam for my 350 TPI IROCZTPI LT1-LT4 Modifications 19 07-12-2010 02:27 AM


Tags
400hp, 400whp, block, cam, custom, dyno, injection, l31, lt1, ramjet, s10, short, stock, thirdgen, westers


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off




All times are GMT -5. The time now is 07:16 PM.


Powered by vBulletin® Version 3.8.7 AC1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Advertising - Terms of Service - Privacy Statement - JOBS
Emails & Contact Details