Guest

This is an engine from an 88 Iroc , 350 TPI.
Currently it has:

Ported AFR 190's, have specs somewhere if you're really interested. Heads were flat milled to 60cc chambers.
KB Pistons, compression is at 10:1
Total seal rings
Cometic gaskets
Comp XFI cam, 232/238 .576 .571 113LSA (spec'd 230/238 .578/.573 113)
PJ 'quiet' gear drive
Ported Edelcrock base
Stock runners <---- How about that? lol
Plenum has EGR walls ground down
BBK 58mm TB
Screen and finless MAF
6E with my own tune
1 5/8" headers that are blocking the top part of the exhaust ports, mix+match of stuff behind that.
Vig 3000 converter
200-4r trans

331.6hp/379.9tq at the wheels. Bit of an improvement over the last dyno run years ago that was 257/282, but there have been many changes since then.

I dont have the graph, but should be getting that although honestly its not much to look at. Was having issues with the trans downshifting so the tq was likely higher because the run didnt start until 4000RPM or thereabouts. Thats where the tq was highest. HP was pretty much flat but the highest point was at 5800 where we let off. AFR was flat, just under 13:1.

Plan to add some ASM runners, some proper headers, and see what happens then.

YenkoST

iTrader: (5)

very nice numbers....can't wait to see the graph/new numbers when you change those things.

91Z28-350

Nice numbers, first I've seen with the XFI cams.

Guest

Correction on above, got charts.

379tq@4580
331hp@4680

HP was tapering off from the peak, unlike what I originally thought. Guess the screen was fooling my eyes. Nevertheless, was still making 319hp@5600 so you wont be hearing any complaints from me.

BigWhiteGTP

Impressive. What is a 6E?

Guest

89 MAF computer/program code.

cali92RS

Thats quite a cam...how does it idle and its street manners? Is this in your's or your dad's car?

I bet you wouldve saved a lot of money if you wouldve bought that Vig converter from me instead

Guest

Yea but yours wouldnt fit a 200, and I had that thing for a couple years before you bought yours anyway. Still got it? lol

Idles ok, somewhat similar to Vincent's car although his idle speed I think is lower and his car seems to lope a bit more probably due to that. Street manners are fine except for a strange somewhat intermittent misfire/hiccup/surge/whatever at cruise but I dont think the cam is to blame for it. Also recently averaged 21.x MPG on a trip recently with 3 people, trunk full of goodies, and 80+MPH speeds. Yes, dads car. Shhh, dont tell anyone. Actually this cam has been much more powerful, friendly, and efficient than the SLP cam I yanked out (224/232 .497/.517 112) but I also changed heads so I dont have a direct comparison. Idle is slightly rougher but not a whole lot different. If you've seen the car in the past year (dont know if you have), thats the cam that was in it. I know some people think my combo has been a little strange but I've been making a slow progression to what I ultimately wanted on there in the first place. Money and convincing arguments were issues for sure, he wanted a carb on the thing. Now that its putting down the power AND the mileage, he's happy as a pig in... well, you know.

If you're around and so is the car, I'll take you for a ride. Hopefully it'll have adequate sized tires by then so it has a better chance of actually putting that power to the ground instead of up in smoke.

dbtk2

Any idea what kind of times it runs in the 1/4 with those power numbers? I'm used to fwd GP's, so I don't really know what an f-body runs at those power levels. My dads GTP with just about exactly the same power as your car (334.3whp/381wtq.) runs 11.9's @ 116, is that about similar?

Those are some very respectable power numbers! Congrats and can't wait to see more from you in the future since thats kinda where I eventually want to go with my TPI project.

Shawn

Guest

Well the car has a traction issue so its a bad comparison. However, a guy that put down near the same this weekend went to the track the next day (Sunday) and ran a 12.7@109.

11.9@116, pretty decent time for that.

cali92RS

I doubt traction would be an issue with both me and you in the car.
Vig is sold, went to Gabe (socaltam).
Those XFI cams look bitchin. Too bad they came out after I got my XE 224/230 cam. Youve heard my cam...all lope. It feels a little dissapointing in the lower RPMs even with the 3.89s, but comes on like a ***** around 3700.
Have you thought about extrude honing that smelldelcrock base? Yes its pricey, but with the bigger AS&Ms, 58mm TB and AFRs, it would probably be worth while. Plus, its only a 20 min drive to paramount.

Guest

Its ported, I opened it up to 1.75 on one end and I think its 1205 on the other. I dont know how much more they could really get out of it.

VincentZ28

iTrader: (2)

Check with Jerry. He might be selling his Stealth Ram. He wants to go Super Ram to pass smog.

My 373rwhp@411rwtq went 12.41@112.24 with a 1.8160ft on Sunday. I was kinda hoping you guys would come and run the car and see the difference it makes.

87TPI350KID

Thats a huge cam for TPI, but it still revs decent.

Some Runners and bigger headers would do wonders.

Orr89RocZ

iTrader: (20)

i'm surprised at how high that power is. 331whp with that huge cam on stock runners is amazing!

i'm gonna run that cam on a 383 HSR more than likely. i'd never consider that cam for TPI, especially a 350 with stock runners

cali92RS

Well now you have proof that you can run a cam that big with TPI and make good power and still have decent streetability.
A lot of stuff (aka bull$hit) get posted on this board about how you shouldnt run this cam with that induction or this part with that part etc. It's all jerking off and conjecture untill someone, in this case madmax, actually runs the combo and puts up big numbers.

Guest

I'm happy with it... for now. Ah who am I fooling. Car guys are never happy with power we always want more. Maybe with the runners and some headers (that is going to be fun... not) I can improve a bit more.

I'm positive there's more to be had with more ideal parts, but nothing says you cant make decent power with things not quite 100%. I'm not going to get into what I might be leaving on the table with a 230+cam and a TPI intake on top, who knows. Surely debatable material right there.

FbodyDave

Those are excellent numbers. I take it it was from Dyno Jet? I am impressed. My Firebird only put down slightly better numbers (read nearly the same) with a 455/profesionally ported round port heads/ comp XHR288 cam/performer rpm/1 7/8 inch Headers/3 inch mandral exhaust with XPipe.All goning through a 700r4 w/ adapter plate and a stock #5 GM converter. I put down 336rwhp 425rwtq. So for a 355 that is awsome. I have only made six passes in the car but w/2.78 gears on slicks my best was 1.9 sixtyft 8.13 @87 in the 1/8 and a 12.62 @108.4 in the 1/4. I feel really good about your combination. I may do something very similar when I get around to a 350 swap in my Iroc

cali92RS

Thats the truth...but sometimes outside forces decide whether or not you are done (like impending project closure and layoffs)

VincentZ28

iTrader: (2)

Hey Ken, How come you didn't make it to the dyno with Madmax, Dyno Don, Brian, Allen and me? Same price, $75 an hour.

cali92RS

No seats...was gonna pick some up last weekend...but something came up (Vegas homeboy).
Besides, I got some more modding to do before i get her dyno'd again. I'll let you know when i go again. I want you to be there when 1st place becomes second

91Z28-350

There's some of that, true. There's the should, would, and could aspect of it. Streetability is in the eye of the beholder. For some, a 220-ish cam is too big, for others, a 242+ solid roller cam is not big enough.

It's not really "jerking off and conjecture" though as your argument is leading down the path of "how much are you leaving on the table by running stock TPI". You really don't want to go down that route. It's not productive.

Most people don't want to pick an inefficient system, especially when they don't have to. If the HSR is legal for a person in whatever state they are in, then there's no reason to stay with TPI and spend $$$ porting or $$$ buying expensive runners. To be honest, there's no reason to stay with a TPI unless you want to, to make a point, or unless you have to.

You can already tell from the peak numbers that there is a choke in the system. There's no doubt that the HP numbers will jump up, literally, once the exhaust and intake are freed up. I'd venture a guess that the intake more than the exhaust in this particular case.

Showing power making examples on TPI is great, the XFI cams look great. The best I've seen with TPI so far on a stout 350. But please don't be antagonistic and come off as all high and mighty about TPI. You're coming off as a heavy TPI advocate in this post. That's fine, but you need to be fair as well...the numbers could be a whole lot better with something else on top. Some of us know what the limitations are and what to expect with TPI. That is the constant battle you see on these boards, TPI vs. everything else....and that's perfectly fine.

Now the big question...will this cam pass smog?

Also, madmax, are you still running the TPI dual filter lid? I wonder if that's beginning to be a restriction for you.

cali92RS

Not true...
There's only 2 choices we have here in cali, TPI or Superram if you want to remain legal...
So, pick your poison.
I just don't like the regurgitation of "facts" without actually seeing any proof. For example, in another post some dude was saying you couldnt get more than 325 HP out of a 400 with TPI...well, obviously, thats not true since here is an example of a 350 with stock runners and MAF making 330. He was just regurgitating some "facts" he read on this board which have been on here a long time.

1989GTATransAm

iTrader: (3)

I was there for the dyno session and a witness. I was very impressed by the numbers Chris's car put down. In fact everyone did good. Vincent was very impressive with his 350.

Orr89RocZ

iTrader: (20)

yeah thats what my arguement would be.. that cam on a hsr or something would pull alot higher rpms. thats why i said i would never consider that cam for tpi cuz the cam's potential is alot higher rpm wise than what TPI can support. but the numbers look great for having a slightly mismatched combo. i mean a TPI with stock runners is lookin like supporting 4500rpms, and that cam will feed a 383 past 5000, so it seems not very efficient to me, cuz your leaving so much on the table. but again, the numbers are quite impressive. thats why tunning is so important, it made it possible to have such a large cam in that motor with that intake.

VincentZ28

iTrader: (2)

I was also there with him at the dyno session. They tried to get the car to run below 3500on the dyno but it kept down shifting. So when they finally got the car not to down shift, it was around 4000 on the down side of the curve. So those are the numbers we saw. We never saw the peak power. But when it down shifted, it flash the numbers of 415rwhp@457rwtq. Is this right? We don't know. But the engine sounds like it has lots of power.

Madmax is going to make more changes when he gets ready and he knows which way to go. When he's ready, he's ready. And he needs to find a way to get pass me!

Guest

Well I dont have a HSR to test for comparison, but I have a single plane I will test, along with the different runners. I may even see how the old siamese base comes up in the curve. I dont plan on making any changes to the rest of the car anymore aside of the intake and exhaust so I should have some other results in the future to make better comparisons to. Should be interesting.

zrated383

Hmm...making me want to go with this XFI cam over the 268 in my 355 buildup. I want to do the same setup with AFR 190s and an HSR. Where are you guys getting your cars dynoed/tuned? Think this combo will run on a mail-order chip from Ed Wright or PCMforless.com? I was almost 100% sure on going with the 268XFI becuase I drive this car everyday and want great streetability. Did you end up going with the whole XFI valvetrain with their pushrods, rockers, and springs? Should I go with this cam rather than the 268XFI? How are your brakes/vacuum issues? Sorry for all the questions, just trying to make the right choice.

Guest

The chip is my own home-brew. I dont think you could get an off the shelf chip to run so well, from what some of the guys there were picking up with tuning on the dyno. Probably leaving ~20hp +/- on the table... of course depending on how close the tune hits. Also there are some of the guys there that were running smaller cams making near as much HP, so dont be so sure a bigger cam is going to make all that much difference. If you've ever played around with Desktop Dyno you might notice that there isnt all that much difference and I'd imagine in reality its probably close to true. Maybe if you were looking for that last little bit of power and it fits your combo, might work out. Cam manufacturers like Comp, Crane, etc generally go with the smaller of two choices, and I agree with them and have recommended cams in the past along the same guidelines. I based this choice on a couple things, one being... ahhhh what the hell, two being the advertised duration, if that means anything worthwhile, was almost identical to the cam I pulled out but the .050 was a fair bit different. Went from 224/232 to 230/238@.050, or 280/288 to 280/288@.006.

This cam is a little more on the radical side of streetable but not anywhere near as bad as I was thinking it would be. Idle is noticable, but not too bad for a cammed car. You sure wouldnt mistake there's a cam other than stock in it though The brakes seem to work fine although every once in a while I feel like they arent working as well as they would with a stock cam, pedal gets a little hard and doesnt seem quite as effective. Truth be known, I have not measured the vacuum at idle yet. For sure I have a bit less than before.

I only have the cam. Lifters are barely better than stock replacements, have comp guideplates, pushrods (just run of the mill stuff), comp magnum rockers (full rollers), and whatever springs came on the heads shimmed up by my engine guy.

zrated383

Thanks for the reply...much appreciated. How is the low end power? Does it feel like the car has no power until upper RPMs? Any vids or sound clips would be sweet if ya got em. I think I may go this route espeically with the mileage you are getting. A $50 vacuum canister would solve any brake worries I have if I don't feel comfortable after driving it. If I go this route...would you be willing to burn a chip similar to yours...paid of course? Not PROM begging though. What length pushrods did you go with?

VincentZ28

iTrader: (2)

His XFI any my Lunati cams are grounded on 113LSA. No problem with the brakes and no problem passing smog.

Oh by the way, you'll need at least a 2400-2800 converter.

zrated383

Yea I know the XFIs are on a 113 LSA. Is yours a custom grind? Are your Trick Flows ported at all? I think I may go with them over AFRs because they are a few hundred bucks cheaper and I am on a strict budget. And I have a 2600 stall sitting in my basement ready to go in with the shift kit this spring.

P.S. Do you have any sound clips of your car?

VincentZ28

iTrader: (2)

The Trick Flows are stock out the box. I bought them for $895 from Performance Cylinder Heads 3 years ago.

My cam is a custom grind from 112 to 113LSA. That was the only change to the cam.

No sound clips! Sorry!

Guest

Low end power? Just fine, thanks. Too much. After we put in the 3000 stall it just got worse

http://home.earthlink.net/~chris.foster/GPrev1.wav (warning, 5mb file) Made a mp3 but it didnt sound very good.

I dont remember what length the pushrods were, but thats sort of a combo dependant item anyway that needs to be checked.

I'm running MAF, are you? I'm thinking you probably have SD in which case my prom would be kinda useless.

zrated383

This is all good news. Glad the cam still makes low end and continues to make power till 6000. I got a 2600 stall. And I planned on gettin a pushrod length checker so no biggie there. Yes my car is MAF. Also...you said you took this car on a trip? I plan on taking a few 2 hour cruizes...is that what you went on?

91Z28-350

How'd you manage that with so much overlap?

VincentZ28

iTrader: (2)

113Lsa make plenty of vacumn.

91Z28-350

I meant passing smog with so much overlap. I don't know your cam specs, but 226/234 113LSA is 4 degrees of overlap, presumably at 0.050. And 232/238 113LSA is 9 degrees of overlap. That's way more than anything I've ever heard of passing the tailpipe test.

****, if that's the case, I'm going to put a rumper in my car too. I just need to know the secret. I was planning on staying 220-224 duration on both intake and exhaust at 114 LSA. From what I understand, that barely passes smog. I'd love to go 230 to 240 on the intake/exhaust durations.

VincentZ28

iTrader: (2)

It's easy! Just tune it for drivability with a wideband O2 sensor. It should stay around 14.7 on the readings. My car is tuned for drivability and for racing in the same chip. It all in the tune.

zrated383

Aright...I think I'm just gonna go ahead and do the 280XFI cam over the 268...screw it...haha. I thought that the 268XFI would be more suited to my current setup (2600 stall, 3.42 gears, soon to be HSR, and 98% street striven, and me being a big fan of low-mid range torque over high rpm power) because I would rather get the most out of what I have rather than spending a couple thousand dollars putting a motor together and in and then being like, "ok, now I need long tubes, 3.5" exhaust, 3.73s, and a new 3000+ converter). I'm just looking at things now. I mean if the 268 would be better for what I have now, I would be willing to have a less radical setup now and look forward to buying a really nice set of AFRs or Patriot Performance heads and a bigger cam to support them in 2 years or something. I hope to get a nitrous kit next winter. Lemme know what ya think.

P.S. I am looking for some low budget heads. I have been keeping my eye open on the classifieds and actually just found a really great deal, but don't have the money right now. Are there any eBay deals or anything that you guys can recommend? Found a sweet deal on a set of aluminum L98s. I need to get the Beehive springs so fully assembled isn't a big deal.

Mkos1980

iTrader: (8)

I've decided on the 268 one. I rarely go over 5500, have a 2200 stall and its mostly highway driving with one or two trips to the track throughout the year.

zrated383

Sounds like me, what are your other mods? I'd like to know how your build turns out.

Mkos1980

iTrader: (8)

383 10:4:1 TF Heads, Miniram, slp 1 3/4 headers. Comp "R" lifters, TF Pushrods, Comp 1.6 Pro Mags and Comp 987 Valve Srings.

700R4 , S-10 Stall converter and 3:27:1 rear

Car is mostly show. I had the LPE219 cam in when I had the LTR and Superram, but now that I went to a mini for less torque "lol" I wanted to change the cams.

Camaroz29

iTrader: (3)

How do the XFI grinds compare to the Xtreme Energy cams? I don't even think Comp has them on their website yet.

VincentZ28

iTrader: (2)

The XFI Cams are on their web site. The XFI cams have a much higher lobe lifts around .570 with 1.6 rockers.

Camaroz29

iTrader: (3)

They aren't included in the "online catalog", but if you search the listings you can find them for sale but not with any specs. Also they don't have "cam cards" listed for them either when I punch in the grind numbers. I guess the main thing I wanted to know was lobe profile, everyone always talks up the Xtreme Energy lobes as being very aggressive and I wanted to know how the XFI cams compared.

Guest

Probably pretty aggressive. 230/236@ .050, 280/288 @ adv. (I think comp uses .006 for adv), .576, .571 lift, 113.0 LSA. Thats off the box. I dont know if the info in the box listed the timing events, but in any case I have that information somewhere. I checked it for myself as well so I can post that too.

Saw a comment above I missed before, the trip I took was not a cruise or any other happy sort of trip, but anyway we drove about 500 miles each way, only stopping for fuel and rest, on the 5 freeway in Cali. Spent 3 days there, so 3 days worth of luggage, some drinks, other assorted stuff for 3 people. Trunk was pretty full.

89IrocZ350TPI

wow those are some impressive numbers.

Julie Bergman

I had some questions related to parts of the conversation in this thread; hope you don't mind a slight hijack!

I recently landed a great deal on a barely used built 383 '91 block for my '91 Formula which presently has a TPI 305. I had just purchased a bunch of CA smog legal bolt-ons for the 305 including SLP 1-5/8 headers. Some folks are saying I should keep 'em because I would lose low-end torque getting the SLP 1-3/4s. SLP says I can send back the headers (new in box) and get a set of their 1-3/4s. The application for my car is a fun street driver occasional hot-lap on track and autox, no drag racing (not my thang, I'm a road racer). What do you guys think?

Much appreciate your input.

1989GTATransAm

iTrader: (3)

Here's my opinion. Go with the SLP 1 3/4" headers with the 383. I going with the 1 3/4" on my new 355. You will have so much torque that even if you lost a couple of ft/pounds down low it would not matter.

With every mod I have done I have increased my torque which makes it a lot harder to get traction. I would not mind killing off some of the low end torque.