anyone that told u youd get 400 hp with a stock tpi intake either lied or nows some voodoo on these engines i built a few tpis i like the torque they make but definally no ls1 in the hp department i would contact pcms for less about the ecm did he port the intake if is stock that a major restriction as converters your has around 2000 stall if stock if u need a bit more get a torque converter for a 96 4.3 s1o they stall out at 2300 behind a v8 car and its still a 12inch converter

 

ya, im going to swap out the intake for sure

 

Wow, that's one heck of a long sentence.

 

I just want my vet to look like the one in the last posters picture

 

I've noticed this in several threads recently. Apparently it's a new contest in C4 Tech....Who can write the longest run-on sentence absent the use of any grammatical rules? Poor spelling is also highly encouraged for bonus points. After all, why communicate clearly? That never helps anything....

 

Then you better be prepared to start beefing up the rest of the driveline for when you leave stock half-shafts, spindles, and the differential strewn all over the concrete.

 

Yes, im aware that even if the motor had the horsepower it would splat everything behind the motor
I dont plan to do it all at once, this is supposed to be a hobby.
if i do everything this winter, i will run out of things to do (that i can afford) for next winter

 

Ok, so I went to my builder today and sugested that he contact PCM for less for the newly tuned chip, and his responce was that PCMforless is who he has been using, and are the ones who told him to put in a smaller cam. have the specs on the new cam now, build sheet now says


bored .030 balanced
full recon on heads 2.02 stainless 1.6 ex 3 angle bowlhawged milled .0019
103523750571 eagle crank
sir7000bblw eagle full float rods h90cp
0.30 speed pro pistons 9.5-1
08-408-8.comp roller cam 2148 roller lifters prw roller 1.5 rockers direct fit headers

they also put in a new water pump o2 sensor, oil sensor and radiator.

The car wont Idle without having the idle turned way up, and it has less power then when it was stock.

Do I assume that PCMforless did not make a mistake and look elsewhere for the problem? or do i bug them till they send me another chip?

 

You're headed in the right direction....building is a test of patience and cash flow...not much else.

Double check your base timing as others have mentioned. I'd set it to start at around 10* and it may need to go even higher as the idle is set right.

I'm curious....what did you do about injectors? stock size? if so they may be way under-sized for what the motor needs. The fun part of Bosch-IIIs is that you can cheat on the size by quite a bit and dial down the pressure to go back close to where you were, and turn it up as needed. If your stock inj were 22lb/hr you could probably go to 26 and then work with the pressure.

The tune will come into play here also...

My best guess is that you need intake work to utilize the head work. You made some nice heads but they're begging for more flow thru the intake. See if someone can check the plenum vac and see if thats increased. It could be starving for air with the big valves. Natural aspiration is tricky. You need vac in the right places and right amounts so you can use it to accellerate the velocity of the air charge. If thats too high of a vac it starves...if the vac is too low you do not pull as much air with each stroke as you need. Velocity is the key...

The power band is unknown at this point, and could still be hiding somewhere in the rpm range. Its very common for L98 enhancements to steal power from the bottom end of the range and move it towards the top even IF the power falls off suddenly at some point.
I did much of the same thing thats you've done and mine developed a horrible power band that was flat as a board on low end. It would'nt break the tires loose on wet streets. I had to work backwards and sorta un-do some things until I got an acceptable power band. Now it pulls hard just above idle,. but surges big time right at 3000 rpm and spins to 6000 between heartbeats...runs good!
That "tune" and that band had to be found by trial & error. Thats all they do at a dyno tune, run it, make some adjustments and try again.
You'll get there.
Just remember, its not the destination so much as it IS the journey that makes the trip worth while.

**************************************** ******

I want to take this opportunity to apologize for having abused (used) puntuation and grammer. Bubba is helpin me wit dat....

 

Please provide the cam SPECS not the part number. What do the heads flow? This will make it easier for those trying to help.

The idle is controlled by the ECM. They can turn the little screw in the throttle body all they want, and all they're doing is messing up the minimum idle air setting. At some point the IAC will be out of range and won't be able to control the idle. They need to set the minimum idle air correctly. Dozens of threads regarding how to do this.

Here is my guess...

The heads are so hogged out that they will only work with a high lift, long duration cam....ie at high rpms...which means there is zero low end with this engine. The TPI intake dies at ~5000rpm.

The cam is mis-matched to the heads and the intake. Can't get enough air in at low rpm and it likely doesn't have enough lift and duration to work at high rpm....if you had the correct intake.

If the pistons are flat tops, they probably have 5cc of relief. Combined with the milled heads and a stock thickness or thinner head gasket, you've bumped the compression ratio (CR). The new CR is probably too high for the current engine such that it is likely detonating. The knock sensor "hears" the detonation before it's audible to you and it's pulling timing....further killing performance.

Given the shop's apparent inexperience with the L98, I wouldn't be surprised if the base timing is incorrect, further causing detonation issues.

I'll assume the cat is not clogged as well.

Bottom line....They are throwing parts at it. Find a new shop and then pay to install matched components that will meet your goals regarding power, reliability, and driveability. Sorry, but the current incarnation is an expensive mistake.

 

Brand COMP Cams
Manufacturer's Part Number 08-408-8
Part Type Camshafts
Product Line COMP Cams Xtreme Energy Camshafts
Summit Racing Part Number CCA-08-408-8
UPC 036584024989

Cam Style Hydraulic roller tappet
Basic Operating RPM Range 1,000-5,000
Intake Duration at 050 inch Lift 206
Exhaust Duration at 050 inch Lift 212
Duration at 050 inch Lift 206 int./212 exh.
Advertised Intake Duration 258
Advertised Exhaust Duration 264
Advertised Duration 258 int./264 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.480 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.487 in.
Valve Lift with Factory Rocker Arm Ratio 0.480 int./0.487 exh.
Lobe Separation (degrees) 110
Computer-Controlled Compatible No
Grind Number CS XR258HR-10
Valve Springs Required Yes
Quantity Sold individually.

 

Well, IF the intake is the problem. that should be remedied shortly, bought eidelbrock high flow base and runners, came with a 1000 cfm throttle body and a plenum port matched to the runners off ebay. They are suposed to install that this week.

A lot of this other information is a bit out of my range, im learning but its a steep curve.

As far as the exspenciv mistake, so far they have stood behind their work, and claim that they wont be finished until i leave with a smile.

Weather or not this holds up as things get more and more complicated remains to be seen.
I was unable to locate a shop in my area with a lot of experience with l98s, so i went with one that had a good reputation for customer service.

I can only hope that they continue to stand behind their work, i have not the knowledge or experience to figure this out for myself, and since the more technical posts i have received on here make my head spin....

I am a bit stuck, I do appreciate the help and I will certainly bring all advice to the guys attention, and hopefully he will be smart enough to know he doesn't know it all.

 

Sorry bad info. This was according to summit.
According to Comp cam This cam is a good replacement to a L98.

 

had me worried/excited with teh computer controlled thing, worried cus it sounded costly and he has already replaced the cam a second time for nothing. But would have been a nice clean answer

 

Ok thats a teeny cam if they cant tune THAT they are idiots doubt thats the case..
Im guessing something else isnt working right. Put that idle screw back where it belongs try and get a scan to see whats going on.
You can have a decent mail order tune but if say a plug wire is bad, timing off, bad cts sensor, bad injector etc the car will run like hell.
One thing at a time.
Bet your heads are just fine.

 

Have you double checked to make sure that your distributor is not off a notch? It's an easy mistake to make, even for experienced builders, and also easy to overlook when troubleshooting. It can make for very diminished performance, even when everything else is right

 

Im thinking they may need to give me a bigger cam. thats about the 4th time someone told me i had a tiny cam........

I wanted it to be very driveable, but i not have thought that they would give me the nearly smallest one possible. maybe i can get PCMforless on the phone and ask them directly what they think of the whole situation.

also doing research into fuel injectors, anyone have an oppinion what size injectors i should be running?

 

Pretty close to a stock cam really.

Start here...

http://www.wallaceracing.com/cr_test2.php

Mechanice builder guy should have figured this LONG before it was put together but it is what it is.

 

IF the curent set up resulted in detonation, and he knock sensor was retarding the timing, would that throw a code?

the only code my mechanic "says" it is throwing is incorrect prom

I have asked him to rescan it and give me the code number.

 

No.