Turbo Iroc - Round Four (Edit: Staying Gen1, new PT7675, heads, intake)
 

The decision has been reached. While I'd love to mod the GT-R or build the 49, the Iroc is the best platform to hack up now that I don't care about it the way I did. I mean I'm no longer worried about ruining its stock appeal (not sure there really is stock appeal to third gens). And most importantly, the Iroc cleans up nicely.

In theory, I already have a 5.3 and 4L80e. It just happens to belong to a friend who just bought a 392 Challenger. As such, he's lost motivation and money to do the LS swap to his 79 TA. He is interested in the 49's engine and trans and some cash to trade for the 5.3 since he can just bolt it in and go. Maybe interested that is.

So the tentative plan is as follows:


1> Get my shop built (I already have the kit for the pole barn)
2> Put Iroc turbo engine in 49 (still might just stick a LS in it though)
3> Do Iroc build


The 49 would be a great ride with the Iroc setup in it with about 12 psi + 700r4. Already has an 8.5 10 bolt so that will hold up fine. I would use cast manifolds and twins on it though. Iroc headers anyone?

Iroc will get tubular K member with LS mounts (thinking BMR), major brake upgrades, lighter wheels eventually. Engine will be stockish 5.3, cam, LS style intake. Fuel system should be set already. Trans 4L80e and a 9 inch. 7876 single or twins? That is the question. Leaning towards twins.

Initial goal 650 rwhp. Beyond that will probably require more engine.

Hoping to have the shop finished with a lift by end of the year. The 49 engine swap by Spring. By the time that is running I would expect to have the K Member and 5.3 already mounted with the beginnings of wiring/plumbing started. All of this depends on money though, and some variables have recently entered the game. I'm basically building with an eye towards keeping costs lowest (hence not doing anything with the GT-R) and leaving open the option of selling the 49 if the variables cycle downward (quite possible due to economy affecting clients).


Let the project begin!

Re: Turbo Iroc - Round Four - 5.3 project!
 

if u dont care about the stock apearing aspect anymore , why not just toss the tpi and and get a single plane or hsr and pick up a ton of power just from that

Re: Turbo Iroc - Round Four - 5.3 project!
 

Awesome! Ill be following this one :)

Jay

Re: Turbo Iroc - Round Four - 5.3 project!
 

Glad to see you are keeping it!

Re: Turbo Iroc - Round Four - 5.3 project!
 

Project... because I want to do an LS. I want coil per cylinder and short plug wires instead of long wires running alongside red hot headers... and about 300 other reasons.

Re: Turbo Iroc - Round Four - 5.3 project!
 

Glad you finally came to this conclusion Steve. I was the same way at first, but there have been way too may 3rd gens that were produced to show any real appreciating value, the way, say, a stock Hemi Cuda would due to the rarity factor. Unless it is a pristine TTA or Firehawk, or one of the prototypes, common 3rd gens will never have the value that we're hoping for, not within any of our lifetimes, that is. Glad to see you're keeping her...

Re: Turbo Iroc - Round Four - 5.3 project!
 

Well, not a fan of the LS swap, but 4L80e + 9" + turbo will keep me here ;-)

I kind of actually hope that these things don't really go up in value. I like to tinker with something that I'm not really worried about at all, I get stressed enough about the things I build for it.... My other project is a '71 Mach 1 (an original 4bbl/track pack car from Arizona) and I'm not thrilled knowing that most things that I change on that car hurt it's value, but since I actually bought it for less than my 3rd gen with

Re: Turbo Iroc - Round Four - 5.3 project!
 

You described an ignition system, similar to the one I and many others are running on our SBC.

What are the 300 other reasons?


I like the LS platform, well specifically the 6.0's as take out motors. I don't think I'd want to spend the money building one up though.

-- Joe

Re: Turbo Iroc - Round Four - 5.3 project!
 

As discussed thoroughly in my previous thread, it is a matter of economics and I'm also tired of going against the grain. I want to become familiar with LS. I don't want to stay 30 years in the past. I want sequential injection. High flowing heads. High flowing intake. Larger throttle body. HIGH FLOWING cast manifolds to convert to turbo manifolds. Cheap replacements to the above when destruction occurs. None of this is possible on a Gen1 without a huge cash outlay. A sequential and CPS capable ECM swap alone would eat up a large chunk of the budget needed to do a 5.3 swap. Plus I need an engine for my 49 that makes more power and I'd rather make the Iroc the race car.

Re: Turbo Iroc - Round Four - 5.3 project!
 

If you do it right you wont have to replace motors.

Just get a strong rod ls motor. Later model gen iv stuff. Early 5.3's bend rods at 600-700 hp. Gen iv rods do 800+

Stay small on cam and not to aggressive. Use good quality valve springs. I would do rering with proper gaps. Freshen up motor bearings. It will last forever with good tune

Re: Turbo Iroc - Round Four - 5.3 project!
 

Can't really fault Steve for wanting to go LSX, as I too want to get back into that part of the game, I miss it. I miss my old' 98 LS1 Trans AM, and my old '07 ZO6, had a lot of fun with them. I'd like to get my hands on another C6 ZO6 and slap on an F1X Procharger this time around though, tired of the turbo issues that always spring up on a daily driver, and they do, most just won't admit it... well, those that drive them hard like I do, that is.

Re: Turbo Iroc - Round Four - 5.3 project!
 

You already have a sequential CPS capable ECM.


Anyway, it's your car and do it as you please.

I'm just saying for future members searching this thread, I don't want them to think they have to go LSx to get any of the above mentioned features. You have been going against the grain for quite some time now. I've been following your build closely, and have noted every obstacle and problem you've encountered. A lot of the problems you've encountered have been directly tied to decisions you made along the way. It's gotten to the point where everyone is simply waiting to see what else can go wrong in your build.

-- Joe

Re: Turbo Iroc - Round Four - 5.3 project!
 

I've always been a blower guy. I've had OEM turbo vehicles, and of course the firebird. The fabrication, heat, etc on the turbo is a PITA.

It doesn't help that the thirdgen engine bay doesn't have a lot of room.

However, I don't know that I'd call a procharger an upgrade. I had a procharger for a year. What an epic POS. They run hot, they have crap efficiency, the whole mounting and belt tensioning system is a joke.

Vortech FTW.

-- Joe

Re: Turbo Iroc - Round Four - 5.3 project!
 

I know the earlier Procharger systems were horrible, but they seemed to have corrected a lot of those issues with the LSX kits, for the most part anyway. Vortech's were always loud, the Mustang guys who dominated the streets when I was a kid ran those. It's just too easy today to build an eight second street car with a blower, and I'd like to explore the cold side wastegate this time around, just pulley up the blower, and control boost via EBC. Can build one hell of a street car and take it anywhere, without a worry...



Sorry for the hijack Steve.

Re: Turbo Iroc - Round Four - 5.3 project!
 

I like the idea. Pictures, videos....

Re: Turbo Iroc - Round Four - 5.3 project!
 

Ouch. Wow.


I think I'll keep my build updates on Youtube then.

Re: Turbo Iroc - Round Four - 5.3 project!
 

Haha atleast you have updates and results unlike half the posts in this forum section

Re: Turbo Iroc - Round Four - 5.3 project!
 

sorry to see you go, always enjoyed watching your build.

Don't listen to these jokers you have contributed more to this site than they ever will.

Re: Turbo Iroc - Round Four - 5.3 project!
 

Jokers?

Nobody said anything about him not contributing. It's just always the end of the world with his build. He's been given advice on a number of things that would have made it easier for him. He sticks to his guns and does it his way. Then more crying about problems.

He has developed reasons why he wants to ditch the SBC and go 5.3, and I simply wanted to point out to others that those reasons are not quite true. We are a tech forum, and posting bad tech should be questioned.

You are not in a position to gauge other members or their contributions to the forum. You've vocalized a number of times now that you are unhappy with the forum, the posting, and the way it's run. Perhaps you shouldn't visit any longer? If we can't make you happy, I'm sure you will find a more welcoming place on the internet.


-- Joe

Re: Turbo Iroc - Round Four - 5.3 project!
 

I didn't mean it as an insult, and we enjoy following your projects.

But sometimes your reasoning is perplexing and you seem to be on a mission of self destruction.

I wish you luck on the new build.

-- Joe

Re: Turbo Iroc - Round Four - 5.3 project!
 

Seriously Steve? I always get notified when you upload a video on youtube anyway, been watching the ones of your new house too, coming out incredible. This was the first thread I was ever pro LSX for a member, and that is mostly because of all of the crap that SBC had put you through in the past. Don't be like that man, keep the thread alive. Dave (project89) doesn't realize how much you're into custom fab work and want to go LSX, he was just looking out for you by recommending an intake swap for what you already had. Joe was just being thorough, wanted a more detailed response for the readers. You gotta see him go off on me when I mention Megasquirt, which is the reason I haven't even mentioned it in project89's thread........ yet lol. :D

Re: Turbo Iroc - Round Four - 5.3 project!
 

I have enjoyed Steve build a ton. I think he's by far the most mechanically inclined IT guy I've seen. I look foward to whatever he does with the car, even if it is an ls. Everyone sees things differently from one another, so you have to set on your own path and follow it..... which Steve does. That, or he's just hard headed on some things, which I am guilty of as well.

Re: Turbo Iroc - Round Four - 5.3 project!
 

I'm interested in your build as I'm in the process of doing a 5.3L twin turbo. Can't let people get to you... it's a public forum and when u post it's like u automatically sign a waiver saying u could get responses that are unwarranted. I personally look at it like for all the haters and people not appreciative there is at least 1 guy who's benefited or learned something from your posts.

Alot of people shunned me when I was putting a 521 BBF in my 87 firebird but now they love it... haters gona hate!

Re: Turbo Iroc - Round Four - 5.3 project!
 

arent we all ?

Re: Turbo Iroc - Round Four - 5.3 project!
 

... too funny, and very true.

Any pics, might have seen you at the track...

Re: Turbo Iroc - Round Four - 5.3 project!
 

FORMER contributor. I'm cleaning up my old contributions. I tried to post the build like I do my videos. REAL LIFE. Real thoughts and feelings. Most importantly I post the fails along with the wins. Apparently that gets an audience anxiously waiting to see my next screw-up. When I contribute here, thirdgen.org gets paid. When I contribute to Youtube, I get a check. I think I'll limit myself to Youtube moving forward. At least I get paid even when I'm getting negged.


I do appreciate the help and opinions everyone has given over the years. Some may call me stubborn but this project was to extract the most I could from TPI and factory plus. I exceeded my 500 rwhp goal by almost 10%. I got within 2 mph of my 1/8 goal. The car would have gotten a 9" (I never expected it to survive with a 9 bolt as long as it did) with the TPI combo but it just never did a mph worthy of spending more. And I'll go back to my reasoning for the very first turbo TPI post. My friend built a stock intake, flat tappet, mild head (world product) 350 nearly identical to my build and went 112 mph in the 1/8 in an 89 Vette. And TurboedTPI ran high 10's on a nearly identical setup with a much simpler fuel system in his Firebird.


At the end of the day I am an awesome builder and tuner regardless of the detractors around here. I've never thrown a rod, spun a bearing or even hurt my transmission build (unless you count the spring retainer plate taken out by the shock of breaking the 9 bolt). And when my head gasket went, my friend took it for a spin and didn't realize the boost was much higher at that time with the dump pipe open. No engine can take 20+ psi and lean out for long. That's more than a number of posters in here can claim.

Re: Turbo Iroc - Round Four - 5.3 project!
 

You gotta realize though Steve, a lot of the subscribers on youtube were referred through Thirdgen.org, as this is where the enthusiasts are. It is a two way street, one feeds off of the other. Most of the comments on youtube are from members here. You're looking at it the wrong way, treat the website like a referral generating system, more members join everyday, and more are interested in boost, not to mention, posting direct links and forcing people to go to your youtube page put's money in your pocket, not embedding them in your post.

I think you are missing the point though with what you just wrote here. Fifteen pounds of boost, with the correct air temps and fuel, will next you double the horsepower. That is not a secret. So if your starting with 250-RWHP, nobody should be surprised by the results at 15-psi, or in your case, 20-psi. What you need to understand is that that 15-psi is being measured through restrictive intake runners, it is just a resistance measure, it is meaningless. The same 15-psi with a better intake manifold will flow way more air at the same amount boost, because all it is doing is telling you how much resistance there is in relation with the turbo, which was project89's argument about a better intake. But I digress...

... in my opinion, that is all thanks to this website. We were with you when you struggled with $59 fueling, we were with you when you struggled with Megasquirt timing, we were with you when you had a fuel pressure issue, exhaust back pressure issue, and an overheating issue, and on and on and on. You were given more than advice, as members here were pointing out the problems, whether junkcltr, or the others, and none of them were ever really appreciated by saying to them "hey, that was it, thanks guys", that might be where the hard headed comes into play. I personally don't feel you owe this website anything, and not sharing anymore is your choice, but nobody here asked you to leave, in fact, it is quite the contrary, everyone really wants you to stay. Criticism comes with the territory brother... ;)

Re: Turbo Iroc - Round Four - 5.3 project!
 

Steve, known you for a long time via the Astro board before this one. Overall, I agree with your sentiment that you post the imperfect with the perfect. Many builds don't have a 100% level of success, and many more builds don't even get far off the ground. It's not all peaches and cream no matter which platform you choose, and the modified SBC was an example of that reality. To this end I thank you for your candor and transparency.

While the philosophy you propose is a doubled edged sword (hopefully eliminating problem elements vs introducing uncertainty via the swap) I don't think your choice is off the mark. The reality is that the economics of an SBC are not what they used to be for a mid HP street engine, and a third gen powertrain is flawed at its power levels. The minute you have to start building one up it kinda sucks because most production LS parts from the block in will cope with power better than a similar SBC component. Even if these ideas don't hold true, if it makes your car fun for you again then it was worth it.

PS:subbed to your channel. Hope to see some good things coming our way!

Re: Turbo Iroc - Round Four - 5.3 project!
 

keep posting,!

Re: Turbo Iroc - Round Four - 5.3 project!
 

I'm just going to cool off for a while.

Re: Turbo Iroc - Round Four - 5.3 project!
 

I hope to see yiu continuing a thread here. Dont worry about all the remarks about going LS. It amazes me how many SBC guys get their panties in a bundle over an LS swap. It not like you are swapping in a 5.0L. Bang for buck you cannot beat it plus there is so much info out there on it.

Its a shame that most people on this board cannot appreciate a nicely done turbo LS. Most seem to only care about cobbled together SBC setups that a terribly mismatched and barely see the road.

Ill be sure to follow youtube!

Jay

Re: Turbo Iroc - Round Four - 5.3 project!
 

Nobody has their panties in a bunch over the LS. The LS is a far superior engine.

I simply pointed out he was wrong on a number of his 'reasons'. He said he wanted sequential injection. That has nothing to do with the LS engine, and he currently has a Megasquirt capable of sequential injection.

He said he wanted high flowing heads. Stock 5.3 heads flow slightly better than vortec heads, and nowhere near what my AFR 210 heads flow. You don't need an LS platform for high flowing heads.

He said "Big throttle body". I ran a 95 MM LS2 throttle body for two years on my SBC when I ran the singleplane intake with the elbow. His choice to stick with the TPI setup is why his intake flows so terribly. You don't need an LS to fix that.

Then the "High flow cast manifolds". I used LT1 manifolds on my turbo build. They had enough material to port to a 1406 to match the AFR210 heads. They flow quite well, and probably comperable to a 6.0 truck manifold.

I had ZERO concern about him wanting to go LS. In fact, I think it's pretty cool. I had an issue with posting opinion not backed by fact. He got upset because I told him a lot of his problems are due to HIS decisions. A LOT of people chimed in his threads thought out ALL of his issues. Every other week him talking about getting rid of the car, etc. Frankly, I'm shocked at how he took my critique, and his behavior afterwards.

I never intended to hurt his feelings.

-- Joe

Re: Turbo Iroc - Round Four - 5.3 project!
 

I know hes sick of the sbc, but the potential was already there without swapping to an ls. As it sits, a different intake and th400 would put it solidly in the 6's. Add a 12 bolt and tbrake and it would go mid 6's.

A 600+ hp 5.3 is going to need a different trans and rearend too. But, I can still understand him on how sick he is of this setup. Not knocking him for swapping at all.

Re: Turbo Iroc - Round Four - 5.3 project!
 

I am very much a new bee to putting a Turbo on anything and have been bitten by the bug to put one on my 87. I've been reading ton's of posts, but find your threads VERY easy to understand and follow especially your u tube video's, like the one called " what you need to Turbo a TPI350", which I found here. From Turbo Iroc 1(I would like to reference in the future and hopefully will be replaced) and now turbo Iroc (4), I feel like they read like a book with follow up information and I RESPECT the fact that you kept it bone stock with great results. my :2cents:
I hope you change your mind and would very much like to follow this build.
:goodjob::goodjob::goodjob::goodjob::goodjob::goodjob::goodjob::goodjob::goodjob::goodjob:

Re: Turbo Iroc - Round Four - 5.3 project!
 

I also want to clarify another component of my reasoning for LS vs Gen1. I'm not at all excited about dealing with converting accessories over etc... but I'd really need to go back into the shortblock as well if I stayed gen1. It just has stock PM rods in it and a 1053 crank. It was never intended to go much over 5000 rpm or make even as much horsepower as it is making now. A failure would be very costly to repair. With the 5.3 it would just be another $450 engine and some head gaskets, not to mention the stock LS hardware is proven in both higher rpm and more horsepower. I could go on and on with reasons. Just know that this is not some thing I want to go with on a whim.

Re: Turbo Iroc - Round Four - 5.3 project!
 

Ok I'm over it. I will post updates here.


Build plan is as follows:


5.3 - not sure on heads/intake but something like LS3 intake with good factory heads. Cam whatever the best 5.3 cam for a turbo setup seems to be (haven't researched yet).


TH400 - trying to stay on a budget, and I can always go 4L80e later if the mood strikes. Possible upgrade to better 1st gear ratio. Transbrake.


9" rear from Quick. After discussing with Orr, I believe the 31 spline axles are sufficient for my short term plans and much cheaper than the 35 route. Whole rear with good locker and aluminum center section less than $2700 delivered. Guessing 3.0 to 3.25 ratio.


AC - forget about it for now


BMR K member with LS mounts. Looking around this one seems to have the fewest complaints vs Spohn etc.


4th gen brakes on rear. Front maybe after market. I want it to stop and I expect it to turn a good number in the 1/4 and 1/2 mile so it needs decent brakes.


Fuel supply - a real fuel pump. No more games.


Goal is high 9 second quarter and low 6 second eighth. Wheels up launch.


My pole barn goes up in about two weeks and I expect to have it walled in and a lift in place by late winter. Nothing much happens before the walls. Lift not required to get started but hopefully I will have it sooner than later.


Anesthes - No hard feelings. I will take the blame on this situation. I'm dealing with a medical issue right now that has put me in a state of fatigue and constant joint pain. It just didn't mix well with your comments on a project that has been a pain in my butt for a long while. At least my Dr now knows what is going on so I can maybe finally get back to some normality soon.

Re: Turbo Iroc - Round Four - 5.3 project!
 

You should just do c5 or c6 brakes up front. it'll keep it simple and can be done for around 500 bucks with just a little bit of work.

Ive been lurking on the site for a couple years and finally made a account. Ive got my ls engines, and figured id try and do something cool with the tbi bird i picked up.

Ill be following your builds :D

Re: Turbo Iroc - Round Four - 5.3 project!
 

12" or smaller with a 15" drag wheel if u plan on skinnies. Else u need a 17" front runner which is alot more $

Re: Turbo Iroc - Round Four - 5.3 project!
 

Glad you decided to stay on here steve. Ill be following your build. Good luck man.

Re: Turbo Iroc - Round Four - 5.3 project!
 

Steve, your build threads helped me out a lot especially when I was first getting my feet wet into the the turbo world. I'd love to see your car pulling the wheels with a transbrake launch! I got a huge kick out of your Hitler videos about the Iroc. Those were great.
One more opinion on the brake upgrade. My experience with the LS1 rears is that they are not very aggressive even with full line pressure (matching the front) and aggressive pads and I don't really know if I gained any stopping power. If I would do it again, I would go with drums that allowed the use of any 15" wheel. I leave my proportioning valve wide open and the rears don't have nearly the power to lock up the rear tires. Maybe it's just my car. Who knows.
The LS1 fronts on the other hand, are one of the best upgrades I've ever done - bang for the buck. 16" wheels are as small as you can go, but in this case it's totally worth it in my opinion.
Subscribed.

Re: Turbo Iroc - Round Four - 5.3 project!
 

If you want it to stop, change the pads to something more agressive. Agressive pads on lt1 brakes can feel like you can do a "stoppie".

Re: Turbo Iroc - Round Four - 5.3 project!
 

You should be able to pull 9s with stock heads probably. A bit of porting wouldn't hurt the factory ones, and if you can fit it under hood a truck intake is fine too. Cam wise look at something like the Isky Triple Twelve.

I'd skip the first gear upgrade on a 400 and go straight to an 80E at that point. You're in almost a grand on doing it and I suspect not gaining a lot. Get a basic rebuild on the 400 and you should be fine for the power levels you want or get an 80E because you don't have the TCU expense if you're using HPT with a factory ECU.

Re: Turbo Iroc - Round Four - 5.3 project!
 

Will be following this closely, glad you stayed! Gona need some ideas with everything so we should be very close in builds. I just started my single turbo 5.3 as well. Literally just dropped the motor in yesterday. Im going cheap, 1999 stock 5.3, didnt remove the heads, or intake or accessories. Pulled the pan and swapped to a Fbody with windage tray and pickup. Swapped stock valve springs for LS6, leaving stock everything else. I got some 60lb (at 43psi) bosch LS1 injectors and harness adapters from FIC (they are 72lb at 58psi) and was told they would support 800hp at 85% DC. I depinned the OEM 1999 LS ECM/harness and going to be running HPT with 2bar SD operating system. Got cheap ebay forward/up SS turbo headers and they fit pretty well. Im going to put a GT45 on it on the pass side and let it eat. 8-10psi and 550-600hp should be expected.

The truck intake will NOT fit with the stock hood. While the back sits below the cowl line the front is up kinda high. Mostly the height of the alternator with the truck accessories But I believe the TB/front of the truck intake would contact a stock hood.

Be sure you verified that its a 5.3 and not a 4.8L. They are the same block and unless you pulled the motor yourself and verified the VIN/RPO codes I would pull the pan and look at the rods, if its a 5.3L then it should have 143 casted into the rod by the rod bolts. If its a different number (forget what) then its a 4.8L. I verified mine when I put the Fbody oil pan. For what its worth the Fbody oil pan is required and so is the Fbody windage tray and pickup. Its not worth cutting the stock truck tray up as the Fbody tray new is like $13. I picked mine up from summit and had them price match it to $198 for the pan. Pickup, windage tray, oil dipstick and tube was like $60 as well. So $260 for all new GM performance parts oil pan swap vs the $370 holley one and holley's didnt even come with a pan gasket which is like $35!

Re: Turbo Iroc - Round Four - 5.3 project!
 

A small update.. not much going to happen for a bit on this one. First I have to get my shop finished and a lift. The good news is that the pole barn just got finished and I'm working on getting the walls planned out. Once we have that I will get the concrete done with the wall anchors in place, then it is just a matter of funding. Once the shop is done, I'm going to get the 49 running with the Iroc engine and 700r4. I'm buying Diggler's STR manifolds and twin 57mm turbos for that.




One thing I might do though is go ahead and start on the Iroc engine removal in the next couple of weeks (assuming I get the concrete down, so I can keep the 49 in the pole barn). I want to take a look at the Iroc's installed position of the camshaft. That has been bothering me for a while and I want to verify position. I'm probably going to swap in a bigger cam for the 49, mainly because I want a bit more lope to the idle as the 49 doesn't need optimum power - it needs sound!!



Finally, I have some good news! I found the 67mm Precision. It was in the right box and I'm not sure how I missed it so many times. Either way, it's in my hands. Now the thought it crossing my mind.. What if.. What if I ran TWO of those 67s on the 5.3? Eventually I would probably go forged 6.0 anyway, but even a stock 5.3 how been known to survive 1000 and those two turbos will support 1200 hp together. So that is something to consider vs running the single 7876.



http://www.mentalsocket.com/iroc87/polebarn.jpg

Re: Turbo Iroc - Round Four - 5.3 project!
 

Nice garage set up! I'm very glad that you are going to keep the car. One more car that will be saved and on the road.

Re: Turbo Iroc - Round Four - 5.3 project!
 

i have a pair of those pt6766's, they came off a car that ran 7.70's @178 with a stock 6.0 block and forged internals. car weighed 3200 (raceweight)

Re: Turbo Iroc - Round Four - 5.3 project!
 

yaj - might as well keep it. It wasn't going to bring enough money so I figured might as well give the Iroc stupid power and leave the 49 more of a cruiser. They will each have a specific purpose instead of one trying to be a do-all car.


Diggler - My friend thinks two 6766's won't spool very good but I reminded him how much better one spools on the Iroc when every other turbo I've tried has been lack-luster. How much trouble did you have on the 6.0 with spooling? What kind of heads/intake did it take to get to that kind of power?

Re: Turbo Iroc - Round Four - 5.3 project!
 

i bought them from the guy, and i never personally ran them. but, his engine was a 408" with out of the box trickflow 225 heads. he said spool was super quick, and he typically left the line at 3000 rpms. th400/3.08 gear, and 275 radials. went 1.30 60's.

lookup the drag week lsx pinto.

Re: Turbo Iroc - Round Four - 5.3 project!
 

What housing? .68-.81 ish ar will spool fine. Put a mild cam in it and dont be afraid of alittle stall speed and trans brake

I've seen 5.3-6.0's light on3 76mm comp ptrim 64mm turbines just fine

My low comp 401" lights up 7268's with .81 ar really quick on tbrake at 4200-4500 rpm! Lol

Re: Turbo Iroc - Round Four - 5.3 project!
 

Thats doing pretty good on stock block. Alot of guys cant keep heads sealed at abit lower hp levels than that. So 408" based iron motor then?