TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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What are the good ones? I thought I heard Edelbrock? How much and where? Anyone have or see many used ones for sale? Reason is because when I get my L98 in w/ the ZZ4 cam, AFPR, headers,etc... I figured that a better TPI base would help alot. What you guys think?
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'91 GTA:5.0TPI-5-spd, Hypertech Stage 2 chip, 160stat,!TB,!Cat, K&N, Flowmaster muffler, Accel Coil,TPI Air Foil, 1LE Alum DS, poly-tranny mount, KYB's all around, & a Hotchkis Strut tower brace.
Mods in progress:
-L98 w/ZZ4 cam/springs
-Edelbrock headers
-3" flow setup
Future:
-T56/heavier clutch
-Hurst or Ripper
-4.10's
-Ram Air II Hood
-1.5" Springs
-Rebuild suspension!
Others:
-39 Chevy coupe
350/350/3.55posi
-52 Chevy p/u
-77 Bonneville 400PONTIAC/400turbo/posi
Original 50k mile 2 door... Gramp's old car!
*** Gotta love those Poncho's***
Just received my Edelbrock Hi-Flo TPI base, runners & 52mm TB today from carpartsonsale.com! The quality is very good. The runners are quite large! The TB looks great as well. All gaskets and bolts were included. I'm stoked that I only paid $578 for both the base AND runner kit and $257 for the TB. Great deal! I also got a K&N cone filter, Accel fuel pressure gauge, and Holley AFPR from them.
Sorry, just looking forward to bolting this stuff together...=)
yeah at least replace that base its the biggest plug in a tpi system besides the exhaust.
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1989 firebird formula
Mods: converted from T.B.I. to a carburator 305 to a 350. Flowmater exhaust,hedman shortie hedders,202 heads,350 horse cam,bored.40 over, Edlebrock torker2 intake.
Future mods performer rpm air gap intake (polished) and 600 edlebrock carb, comp roller cam, and way better headsa 400 defintely in the works!
1. Actually, the stock base is not that big of a restriction. In testing, the base has been shown to be able to outflow the Corvette heads(and a few aftermarket heads as well). The fact that the Corvette heads are used on crate motors with 355 horsepower would indicate the real obstruction in the TPI lies between the TB and the base. Even then the individual parts do not lack in flow. So while the individual parts all have good flow numbers, when combined the total flow drops off significantly.
The real problem is the "Tuned Port" part of TPI. The long runner length(from the plenum to the intake valve) emphasizes mid-range velocity over top-end volume. The obvious cure(s) are: shortening the distance from the plenum to the intake valve(SLP semi-siamesed or Accel SuperRam runners) or using a larger runner cross-section(runners and base) to increase top-end volume(sacrificing some amount of mid-range velocity).
2. Because I see a TPIS "Big Mouth" base somewhere in my near future, I am curious why a few people refer to this as a modified Edelbrock unit. Nowhere in it's advertising does TPIS make mention of this base being manufactured by another company. In fact they stress they designed and manufacture this manifold. Could someone with facts clear this up?
BTW, the TPIS website lists the "Big Mouth" base for $425.00, which is competitive with the "smaller" Edelbrock unit(avg retail $400). TPIS will port-match the base to your runners and heads for an additional $75(which is reasonable), but as someone else mentioned: if you want to save a few bucks you can do the port-matching yourself.
3. $578 for the Edelbrock base and runners is a very good deal. Especially when the source you mentioned(CarPartsOnSale.com) lists the package for $662.21! I am opting for a TPIS base, SLP runners, Iron Eagles(180cc) heads combo. So it is unlikely I'll score any combo deals, as I will need to source from three different companies.
The information on the TPIS base comes from the knowledge of the mass of members of this board who have purchased that manifold. Trust me and others who say it, the manifold is cast by edelbrock with the TPIS logo on it. Like everyone says, they basically just port match an edelbrock.
Heres a few flow numbers for Accel stuff. As 88 indicated the individual pieces can flow as much or more than many heads can pull by themselves. The “problem” lies that a short radiused entry is usually used when flowing heads and intakes as individual pieces. Anyone with flow bench experience knows manipulation and size of this entry can effect flow numbers. When you do away with that radiused entry and start bolting the intake to the heads,, or the runners to the intake in the case of the TPI,, you get very different flow numbers. The numbers below should give you an idea of that.
Stock base ------------- 222.5 cfm
Accel base ------------- 251.5 cfm
88 is also correct about the length and the diameter of the runners and entry and exit ports effecting torque and horsepower.
Intake....... length ......... port in -- out
Stock GM Base---6.375"------1.47"- 1.96x1.2
TPiS base-------6.125"------1.75"- 2.09x1.28
Accel base------6.125"------1.75"- 2.09x1.28
Runners
Stock TPI-------7.250"------1.470" round
SPL ------------6.625"------1.600" round
Accel LTR-------6.625"------1.615" round
TPiS------------7.625"------1.660" round
Accel Super Ram-4.125"------1.87x1.97 D shaped
Catagory by itself (one piece unit)
TPiS Miniram----3.500"------2.6x1.35--1.96x1.20
Here’s how a few intake/runner systems effected a warmed over 355 with "old style" 64 cc GM heads, Edelbrock RPM cam, and headers to compare EFI systems.
Keep in mind there will be an optimum combination for any given set of parts. ASM (LTR TPI), ACCEL Super Ram, and the TPiS Mini Ram are all different enough that each one will perform best with a combination that they were designed to work on,, or for. If this had been a high rpm 406, the numbers would have been quite different.
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86 IROC - 9.8:1 - 355, TFS twisted wedge heads, 218/228-110, fully ported GM base and plenum, SLP runners, 52mm BBK, 24# SVO, 88 350 GM EPROM, 1 5/8" Headman headers, 2.5" Dynomax, TH350, 2200 stall, B&M Megashifter, 3.23 peg leg, 245/45ZR17 on 212 Eagles - Best run - 12.53/112.4 on 26x11.5 ET Streets.
Very good info you've provided. I've seen a lot of those numbers in other places(usually in older issues of HTP), but it's good to have them all together for direct comparison. Perhaps someone could put them into the FAQ(hint, hint) along with the data on different runners. The dyno comparison is a real eye-opener though. I didn't think the AS&M LTR's were worth the extra $$$, but they definitely produced the best overall numbers. Got me re-evaluating my budget. Could you post where you got the dyno numbers from(a magazine test I'm assuming). I'd like to see what heads, cam, exhaust, etc.,... they used. That info would be helpfull in deciding if the resultant motor is one I could live with(and afford).
I don't have a problem with the TPIS base being made by Edelbrock - just wish if that's the case, that TPIS would say so instead of claiming they manufacture it. Scoggins-Dicky has no probs admitting their upcoming base will be made by Mr. E. And let's face it, Vic's boys can probably make it a lot cheaper than a smaller operation without their own foundry.
I'm still leaning toward the "Big Mouth"(when I'm not trying to figure the AS&M into a 'reasonable' budget), even if it is made by Edelbrock. The small difference in price is justified, in my opinion, by the fact that the TPIS base has already been hogged-out(rather than just port-matched). Actually when you price out the burrettes, sanding rolls and emery cloth(I like to do the final polish by hand) and the time involved, TPIS's price for port-matching is very cheap.
You’re right the flow figures are from the July 1996 High-Tech Performance article “Altered Profiles”, by Ray Bohacz.
The runner lengths (some personally verified for accuracy) come from a special edition series “Chevrolet Small-Block Engines”. I extract and file articles I feel worthy of keeping and discard the rest of the magazine. Most articles indicate the date on the pages, this one did not. I’d guess it to be around 1991 – 1993.
The dyno figures are from a December 1991 Car Craft article entitled Injection Selection,, and there were other systems tested,, I just relayed the most popular selections. Unfortunately there is not much more detail in the article about the engine other that whats indicated on the previous post.
I want to throw in a disclaimer. I usually refrain from posting numbers from articles. There are just way too many variable that are involved that may or may not be disclosed,, whether honestly or not. That withstanding, I've seen how some on the board hammer anyone that quotes articles. I understand the game after 21 years of racing and building engines (and having a few dynoed) I usually have no problem identifying something that stinks, all these appear to be on the up and up.
Many folks are skeptical about how bias the author or operator is in regards to the magazines. Certainly there could be a temptation to skew the results, and certainly if the manufacturer or company supplying the product is aware of a "shoot-out" there is a potential of them sending a "ringer". For instance, did they send the same set up you and I would get if ordered,, or did they spend some time "cleaning it up",, maybe do some porting? Other things to consider: Did one "brand" send a "chip" with theirs and the others used the stock chip? Was a “ported” plenum used throughout the testing? What size throttle body was used? Where did they set the fuel pressure, what was the base timing, where was the TPS set – were these optimized for the combination? You just don't really know when you read this stuff.
OK,,, ASSUME this was a 100 fair and equal as equal can get test. In this particular article (IMO) it appears ASM was the better intake system for this combination (best peak torque, and best HP/TQ average). The ASM "system" included an extrude honed GM base and plenum, their runners, and a 58mm T/B. Not cheap,,, and because it looked the best here,, it may not be the case for another application with different compression, heads, and cam.
I'm pulling in all this info I have aquired over the years for a web page. I need to find out what the protocal is for using scanner images from magazines though.
[This message has been edited by BadSS (edited January 20, 2001).]
I fully agree with the fact that different intakes are going to need different supporting casts. If the above dyno engine was configured for any type of engine, it would be a carb/TBI combo. Yet the test results indicate none of the combo's were optimized with this set-up(notice the very short powerbands exhibited by all), and in a skewed kind of way, that makes it a fair comparison for all of the intakes.
I'm glad you mentioned the Extrude honing on the AS&M plenum and base. It's not an option I am considering, due to it's very high cost. But it would be interesting to know how the LTR's would have fared without it. Also, because I am considering both types of semi-siamesed runners(SLP's and AS&M's), I am curious how they fare against each other. ASM's product would need to offer a substantial advantage as the SLP runners can be had for $279(including all gaskets and mounting hardware) vs $475 for the AS&M's(bare runners only).
The TPI intake needs to be attacked as a whole for best results.
I see some put runners on a otherwise stock intake and get no results.Optimize everything up to the new manifold(which ever one you decide on)to get it s full potential or close to it.
Either edelbrock or TPIS one is good,if you want it already to go,get the TPIS...if you know someone that coud do it for you for a good price get the edelbroks.
Save money everywhere you can even if it's $50....you will quickly find in this hobby you never have enough of it.
I had good luck with SLP runners because they are cast. Get a cheapy dremel with a flex wand and carbide and grind the runner dividers to 1" of the bottom and knife edge and gasket match 'em. It took 2 weeks but they made a noticable improvm't. Of course you hafta grind the base port roofs up (don't grind the floor). I slapped on SLP headers/y-pipe, 58mm TB, ZZ4 cam, 1.6 rollers, adj. fuel press, stage 5 TPIS chip, removed the smog pump..... Ported the plenum to match the tb... 4.10 w/Auburn posi... Ported heads (I didn't do these myself though)
My buddy did a few mods and his car runs the same as it did before... He got disgusted and bought a MUS@@NG. I guess you hafta attack everything at once to make a dif on a TPI.
Traxion posted a very lengthy thread a while back in the Aftermarket Products forum about the AS&M vs SLP runners, and why the AS&M runners are better. Do a search for it. I've got the TPIS large tube runners now, as I got them used. I'd like to get the AS&M semi-siamesed runners, as I think they're better for my setup. But like you said, I dont want to spend the $475 on a new set.
I GOT THE BEST INTAKES U CAN BUY DUDE....CHECK OUT MY AD IN THIS SECTION..IT HAS ALL THE INFO U NEED AND POWER NUMBERS TO BACK IT UP.....IF U GOT ANY QUESTIONS FEEL FREE TO LET ME KNOW.....IVE BEEN SPECIALIZING IN TPI SINCE 1985.THE PRICES ON THESE INTAKES ARE A STEAL!!!!
I have the Edlebrock manifold on my '89 350 TPI Formula. The plenum was cleaned up, but the runners and heads are dead stock (with a nice dent in one of the tubes ) I am using ADS 24# injectors with an AFPR. SLP exhaust,airfoil and modified MAF w/open cone K&N.
It pulled 218RWHP and 288RWTQ.
Add 20% for driveline losses and it pulls 261hp and 345tq at the flywheel. This was done with the timing and TPS out of whack and a slightly slipping trans. I did not see very much gain for the $350 I spent on the manifold, even with the tuning it needs. If you are going to replace intake parts, I recommend planning to do the whole thing. The hose can only flow as much water as it's smallest section.
) I am using ADS 24# injectors with an AFPR. SLP exhaust,airfoil and modified MAF w/open cone K&N.
