My TBI350 upgrade path

[bretsk2500]

Phase I:

Summit K1102 Cam/lifters 204/214@.050
Edelbrock 3704 intake
Crane 99848 springs
and of course the crome steel timing cover and SS intake bolts.

I'll be rebuilding the TBI unit at the same time

Cost ~$450 gaskets & all.

Phase II

Flowtech Afterburner 49156FLT full length headers
Flowtech Afterburner 49156YFLT matching Y pipe
Catco 9007 universal 3" Cat (up to 7.7l engine)
Flowmaster 17126 3" single force II cat back.

Y pipe will get new 02 sensor.

Cost ~$650

Oh and some where in there will be a Wait4Me tune. I hope to be able to swing Phase I&II at the same time. does this sound like a good setup?

it's going in a 88 K2500, 700-r4, 3.73, 32" tire that frequently tows to 7,000lbs. I'm looking for overall better performance.

[1989K1500]

Originally Posted by bretsk2500

Oh and some where in there will be a Wait4Me tune. I hope to be able to swing Phase I&II at the same time. does this sound like a good setup?

it's going in a 88 K2500, 700-r4, 3.73, 32" tire that frequently tows to 7,000lbs. I'm looking for overall better performance.

Cant get a tune. Only Vortec motors can be tuned. You will need a chip. like from www.tbichips.com

[bretsk2500]

oh.. ok.. insert "custom chip" for Waitforme tune.

[Diamond Jim]

Your wasting your money! You need to replace the heads first, or at lest have some major work done on porting them. Heads are the hold up tbi motors.

[Fast305]

Originally Posted by Diamond Jim

Your wasting your money! You need to replace the heads first, or at lest have some major work done on porting them. Heads are the hold up tbi motors.

I used to believe that until I swapped a set of 083s for the old 193s and saw no gain. Tuned it and basically saw the power I would have seen from tuning it with the 193s. Swapped the cam to a LT1 roller and power came up immediately. Then swapped over to the 193s that I ported and power went WAY up. All in all the stock TBI heads are NO worse than other factory smog heads with the exception of L30/L31 vortecs and some old Corvette Heads. In several aspects they are better than your older castings.

The WASTE of money is going to be buying a chip mail order instead of learning how to and burning your own.

[BeaSSt]

I'd agree w/ Jim, on the head work/swap. I've basicly done what your talkin about here w/ my '91 Z71. Thro, I haven't made to around to gettin the headers installed, yet. And thro, I do have decent power and probably well show some incl. w/ addition of the headers. My #1 concern was that, I'd done alill more w/ the tbi heads. Back while I was performing the overhaul. Instead, of just havin 'em re-worked, maybe the portin-n-polishin of the tbi heads or a total head swap. You may wanna check into doing something like that w/ the heads.

But, other than that, the 350ci in my Z71 runs great and sounds fantastic, now.

Good luck,
Don

[TINY'S97]

from my personal experience with my 87 tbi, i'd recommend chip, pulleys, intake, and k&n. tried the biggest crane cam that was offered and would have been a lot better off with the stock one, IMO. as far as heads depending on how radical you want, just have the stocks re-worked with all new goodies. i see you already have 3.73, if you don't already put a good posi chunk. and last find a good shop, one that uses trans-go stuff preferably, and have the trans redone with shift kit and corvette servo upgrade.

[bretsk2500]

Originally Posted by TINY'S97

from my personal experience with my 87 tbi, i'd recommend chip, pulleys, intake, and k&n. tried the biggest crane cam that was offered and would have been a lot better off with the stock one, IMO. as far as heads depending on how radical you want, just have the stocks re-worked with all new goodies. i see you already have 3.73, if you don't already put a good posi chunk. and last find a good shop, one that uses trans-go stuff preferably, and have the trans redone with shift kit and corvette servo upgrade.

I don't want a posi... having the ass end pass me in the snow is no fun at all.. trans was built up 3 years ago, so no worries about it. K&N's are a poor filtering waste of money.. been there, done that. that 10" paper one I'm running will flow about 4x what my engine can suck through the throttle body.

I've toyed with doing the heads.. that'd be more money than I can swing at one time for now.. maybe it'll be phase III.... vortec's would be nice, but I don't want to have to buy the $400 GMPP manifold and jury-rig the EGR setup.

[Frankenbiker]

If I were you, I'd swap the order on your Phase I and Phase II. Then ditch the "flowmaster" name and get another; you're paying for a name there. I bought a Magnaflow high-flow cat and muffler, and had it all welded up for half that price. I've also been told (and experience to back it up) that headers will be largely useless until you get past about 3500 RPM, although a non-stock cam might change that. If you spend lots of time in the 1500-2500 RPM range, you'll have better luck with the stock manifolds, believe it or not, and have far fewer problems with having to tighten your header bolts every weekend. If you've got a laptop, go download WinALDL and log a couple of hours worth of engine data. (besides, Brian at TBICHIPS.COM will want it anyway.) Import the data into Excel and graph your RPM. Look at where you spend most of your time. If, like me, you spend most of your time on the freeway, you'll have more than 95% of your RPM below about 2200 RPM, with occasional and infrequent bursts to 3500-4000 as you hot-shot up an entrance ramp. An engine in that range has no use for headers; they'll just annoy you with noise. And believe it or not, as long as you're staying south of 5000 RPM, the factory manifold will be hard to beat. (Believe it or not, GM engineers aren't stupid; misguided maybe, but not stupid.) HP Books "How to Build A Small-Block Chevy" observed that below 5000 RPM, whose manfold was "better" was an inconclusive arguement at best. That changed over 5000 RPM, but for a working truck, over 5000 RPM will hardly ever, if at all, be seen.

And as someone else around here has had less than stellar luck with the K1102 Cam, (see http://www.fullsizechevy.com/forums/...ighlight=k1102) I'd be looking for another there as well. I have a strong feeling that if this is a daily driver, you'll hate having a rough-idling truck after a month or so. I had suggested to me to use a Comp Cams X4250H (P#12-231-2) since it has lots of low-end torque. I suspect anything in the X425* family would work well. (Go to www.compcams.com an search "4x4". You'll get that family.) In any event, you'll need a new chip once the new cam is in. You might be able to get away with the stock chip for a while, but you'll likely run the risk of burning the motor up, since the stock chip is frightfully lean in the first place (mine was running 16:1!! At WOT.)

Yeah, I know all this largely flies in the face of what else has been suggested, but after having been down this particular road with two trucks that must earn their keep, sometimes having a fire-breathing hotrod is more trouble than it's worth.

-blaine

[bretsk2500]

The thing is, the cam, springs, and intake are all TBIchips.com recomended parts, as are headers and a new cat.. I'll probably have them do the chip for it as well. Bulldog350's issues with the K1102 stem a bit from re-using the stock springs w/ a stock exhaust. I also don't think the combo I've selected will be anything near a "fire breathing hotrod". I rarely if ever take the truck on the highway, mostly in town or backroad driving.

[billdog350]

I definitely have to slap new springs on there to tell you what gains the K1102 is REALLY good for....but I'll tell you for sure that the best bang for my buck since I've owned the truck was the $131 for the Moates programmer, chip and adapters, as well as the $20 for the datamaster definition file to program it. Add that to the dyno time for $50 and I gained 20rwhp/tq in the mid range....$200 for 20rwhp? Good luck getting that with ANY other mod....the cam didn't seem to make much of a difference, but again we're talking an engine with 155,000 miles on it so the compression and valve springs aren't in "new" condition.

[bretsk2500]

I wish I knew of a dyno place around here.. the only one I've found is for a NASCAR team up in Westbrook, but I really doubt they rent the thing out.

I was messing around w/ dyno2000 this weekend and I put in the cam's profile (timed it straight up), 500cfm 2bbl, dual plane, headers/mufflers and got 239hp@4000 and 379tq @2000.. if that actually panned out like that I would be VERY happy. everything drops like a stone after 4k, but that's to be expected with a towing cam and stock heads. I'm going to fiddle with it some more just for kicks.

Billdog, where did you get the programmer?

[Fast305]

Originally Posted by bretsk2500

I wish I knew of a dyno place around here.. the only one I've found is for a NASCAR team up in Westbrook, but I really doubt they rent the thing out.

I was messing around w/ dyno2000 this weekend and I put in the cam's profile (timed it straight up), 500cfm 2bbl, dual plane, headers/mufflers and got 239hp@4000 and 379tq @2000.. if that actually panned out like that I would be VERY happy. everything drops like a stone after 4k, but that's to be expected with a towing cam and stock heads. I'm going to fiddle with it some more just for kicks.

Billdog, where did you get the programmer?

Actually the bone STOCK TBI being shrouded by the stock spacer ring is about 420 CFM @ 1.5" HG pressure drop. I ran your same specs through using head flow data from a pair of stock 193s and cam data from summit.com.

Here are my results through a stock Exhaust system and TBI manifold.

RPM-----HP----TQ
2000----128----335
2500----163----343
3000----199----349
3500----225----338
4000----240----314
4500----241----281
5000----224----235
5500----192----183

[bretsk2500]

are you using dyno2000? the head file I used was called sbc_gm_87_91_041_stock_casting I used 1.72/1.50 valves. I don't have a specific head listing for a 193. I also don't have a specific listing for a TBI manifold.. figured a dual plane was close enough. When I swapped in a set of L98 heads, I was up to 335HP

I junked that PCV spacer long ago.

[Fast305]

Originally Posted by bretsk2500

are you using dyno2000? the head file I used was called sbc_gm_87_91_041_stock_casting I used 1.72/1.50 valves. I don't have a specific head listing for a 193. I also don't have a specific listing for a TBI manifold.. figured a dual plane was close enough. When I swapped in a set of L98 heads, I was up to 335HP

I junked that PCV spacer long ago.

I am using DD2000 as well. Unfortunately here is what I get with the CAST IRON 083 L98 TPI 350 castings(Power lost, but not unreasonable as the exhaust ports flow less on the 083s than the 193s and the intake is very similar). Here is the stock manifold/ exhaust version for comparison to the 193 headed model. (The 193 flow numbers are from an unported set off of a 1995 tahoe 350, the 083s are the stock #s from the L98 cast iron project on TGO. I don't have a listing for the TBI intake, but use the Dual Plane function as it is modeled after a typical chevy small block stock intake.

RPM------HP------TQ
2000-----125----328
2500-----159----334
3000-----194----340
3500-----219----329
4000-----231----304
4500-----229----267
5000-----206----216
5500-----172----164

Add Headers

RPM------HP------TQ
2000-----142-----373
2500-----178-----374
3000-----212-----370
3500-----244-----366
4000-----265-----348
4500-----268-----313
5000-----250-----263
5500-----222-----212

Now lets go back and model the 193s again.
RPM------HP------TQ
2000-----143-----374
2500-----180-----378
3000-----215-----376
3500-----250-----374
4000-----275-----361
4500-----288-----336
5000-----279-----293
5500-----255-----244


See why I am not in a Hurry to go out and buy the 350 TPI castings unless I plan to work them over really well with a grinder. You will actually lose a little power by going to the 083 head from the 193.

[Fast305]

Just for grins I bolted on a pair of Vette Aluminum L98 heads. This pushes compression to 10.2:1 up from 9.3:1 due to the 58 cc chambers vs 64-66 cc of the 193s.

Cast Iron Manifolds/Stock Exhaust
RPM------HP------TQ
2000-----132-----347
2500-----169-----355
3000-----208-----364
3500-----237-----356
4000-----257-----337
4500-----266-----310
5000-----255-----268
5500-----231-----221

Headers/Good Exhaust
RPM-----HP-----TQ
2000----149----391
2500----188----395
3000----225----393
3500----261----392
4000----291----381
4500----309----361
5000----308----323
5500----290----277

Finally I went to Cast Iron 062 vortec heads. Compression stays untouched from the 193 combo at 9.3:1.
Cast Iron Manifold/Stock Exhaust
RPM------HP------TQ
2000-----149-----329
2500-----161-----338
3000-----200-----349
3500-----230-----345
4000-----250-----328
4500-----260-----304
5000-----251-----263
5500-----226-----216

Headers/Good Exhaust
RPM------HP------TQ
2000-----143-----374
2500-----180-----378
3000-----217-----379
3500-----254-----382
4000-----285-----374
4500-----304-----355
5000-----304-----319
5500-----287-----274

[bretsk2500]

can you email me the 193 flow model? bretsk2500at yahoo.

thanks :)

I'd be damn happy w/ 288HP/379tq.

[Fast305]

I tried to Email but it came back saying undeliverable.

Here are the numbers @ 28 in/h20 pressure drop through a stock untouched 1995 Tahoe 193 head w/ 1.94" & 1.50" valves.


------------Intake-------Exhaust
Valve Lift----Flow---------Flow
0.050--------38.7---------27.6
0.100--------70.4---------55.7
0.200--------100.2--------115.6
0.300--------145.7--------125.8
0.400--------164.7--------138.9
0.500--------178.9--------146.8


Here are the stock 083 TPI numbers I have.

------------Intake------Exhuast
Valve Lift----Flow--------Flow
0.100--------53.9--------41.6
0.200--------111.2-------95.2
0.300--------157.3-------112.4
0.400--------182.0-------116.6
0.500--------192.3-------116.9
0.600--------193.6-------117.6

[Fast305]

Originally Posted by bretsk2500

can you email me the 193 flow model? bretsk2500at yahoo.

thanks :)

I'd be damn happy w/ 288HP/379tq.

288 @ 4,500/378 @ 2500 turns to roughly 230 @ 4,500/340 @ 2,500 at the wheels. That is aweful close to Airdeano's 212RWHP @ 4800rpm /348RWTQ @ 2400 rpm. His mods list is very close but I believe he is using a Crane 2030 which specs a little different.

For his truck I get about

RPM------HP-------TQ
2000-----149------391
2500-----182------382
3000-----216------378
3500-----246------369
4000-----265------348
4500-----268------313
5000-----254------266
5500-----224------214

Or 220 RWHP @ 4,500 and 352 RWTQ @ 2,000 and 344 RWTQ @ 2,500.

[phuzn]

i want those numbers out of my TBI...