am looking at gear ratios and for the rear diff I just dont know what would be best for street/roll racing would be. I am thinking a 3.5?

I am running the Tacoma 3.56 r&p inside the stock IS diff. It’s the tallest gearset from Toyota that will fit. You have to go to a GS400/Supra diff if you want taller in a Toyota housing. There’s some fab work and axle changes involved. I don’t have a T56 though. I’ve got an AR5. Seeing as you have one more gear to grab, I would probably go a little shorter with a 4.1 diff from an IS or a BRZ/FRS. It will launch better and that .5 (or is it .63? - either way, still nice) ratio 6th gear will still let you cruise at low rpms. I’m not sure how long the IS diff will last at 1k hp though. Grannas does offer that Ford rear end swap, that would handle the power and have a ton of available gear ratios so that’s an option as well.

 

Nice , great info. Thank you sir.

As far as i have read the t56 magnum F , if measured from end of input shaft to shifter... it is 3 to 4 inches roughly more distance than a standard tremec t56 magnum. Can anyone say from experience? The few i know who have is300 or sc300 run the tremec t56 magnum.

 

How is this project coming along? I'd love to hear more about it.

 

Going to primer engine bay tomorrow. And have t56 magnum F and grannas built ford 8.8 ready to go. Welded figs reinforcement plate to rear sub frame. Contemplating on 10pt cage. Engine is at machine shop and head will go for porting soon..

 

Very impressive! A whole lot of time, money, and planning are clearly going into your build. I look forward to the updates to come.

 

My main concern right now is if the protunerz intake manifold will fit in the is300 engine bay. Also hoping it will hold 40+lbs of boost. I am looking to run the PTE 7685 OR might jump on the new 8080 😎 i have alot of work ahead and the wiring in the is300 is a nightmare. Originally planned on full wire tuck. After reviewing the wiring and my options, i may not go that route.
I also have an infinity 506 which i am rolling the idea of selling and jumping on a Haltec as the build may warrant it.

I have been also working on a 1928 model A with a built chevy 472ci and a ford 9" . This thing is wicked! It has a turbo400 trans with a 3500 slip converter. There is this knob you turn and it slips the converter untill 3500rpm then you can engage it for launch, kinda like hoe a 2 step is used but more mechanical. So i have been a little busy. Will post more on the 2j when the engine comes back from machine shop.

I am wanting to keep the car (is300) black and go nardo grey for engine bay. Will update when I have more to post.

 

Lil progress update

 

Pocket porting has started

 

Needs polishing....

Anyways i have a question for the sulra community :

Why is it that when searching, i see tons of hogh hp supra builds, but barely any high hp is300 builds? I know people are going to say because , dude, its a supra but lets be practical. If i can literally do the entire swap to an is300 and build an 8 sec car for 1/4 of the price, why not? Im having a hard time trying to find some of these builds as there arent many, even in the IS forums. A few on youtube with limited details, murda2j is a good example with his 8385 build .

Im wondering if it has to do with the rear tire size? I think the is300 is pushing it on a 275-50-15 or 285 with not much room to go bigger if im not mistaken, around those sizes. I see tons og sub 1000hp is300s but anything over that is limited.

Anyways, 8385 and grannas NA GE manifold will be ordered this week. Machine shops here in ca. are backed out like 8 months but my turn is finally coming up. Cant wait to get this in the car finally so i can do some tinkering.

 

Needs polishing....

Anyways i have a question for the sulra community :

Why is it that when searching, i see tons of hogh hp supra builds, but barely any high hp is300 builds? I know people are going to say because , dude, its a supra but lets be practical. If i can literally do the entire swap to an is300 and build an 8 sec car for 1/4 of the price, why not? Im having a hard time trying to find some of these builds as there arent many, even in the IS forums. A few on youtube with limited details, murda2j is a good example with his 8385 build .

Im wondering if it has to do with the rear tire size? I think the is300 is pushing it on a 275-50-15 or 285 with not much room to go bigger if im not mistaken, around those sizes. I see tons og sub 1000hp is300s but anything over that is limited.

Anyways, 8385 and grannas NA GE manifold will be ordered this week. Machine shops here in ca. are backed out like 8 months but my turn is finally coming up. Cant wait to get this in the car finally so i can do some tinkering.

Honestly it's because it's a total motherfucker to do if you're trying to keep the the factory gauge cluster, creature comforts, and OBD-II compliance where inspections are required to register the car. For areas where you can build a full-send because-racecar yeet machine and it gets a license plate as long as you've got insurance, it's a lot easier. But the CANbus dash and gauge cluster and overall body wiring still turns into a problem.
As you've already noticed, the rear end being essentially the same diff as what was sold in the MK3 Supra and GT86 is an issue as it's not as strong as the factory 6-spd USDM Supra diff. It also has a much more limited range of available ratios but those ratios do match excellently with the Magnum-F so you're set up for success there.
Downside is, as you've also noticed, there's minimal tire space for big meats and the rear diff will ultimately fail with sticky tires on full send much above 900-1000 tops.

If you're dead set on an 8second performance goal with the H-pattern Magnum-F, you'll definitely want to go 8.8 rear and get weird with overfenders or mini tubbing in the rear for more tire.

 

Awesome info

Yes i have gone full standalone on aem.
I got the ford 8.8 from grannas kit in 4.10
I suspected i will probably need to cut/over fendors which is fine, i would prefer not to do any body work as its the absolute worst but it could be worse.

Thanls for clarifying my guesses as this has been a journey, and not as easy as the old 700hp integra.

 

Lil update, turbo came in. 8385 sportsman with 1.0 ar and vband

Thiiick (in my trump impression)

 

Nice work so far! One of the fastest cars I've ever been in was a built is300. Not a lot of cars out there that you can throw 3-4 buddies in comfortably and beat nearly anything on the street, then take on a random 4 hour road trip that next day.

 

My own IS300-T is not the fire breather yours is, but I also have a T56 Magnum F arriving from Grannas shortly, so I'm looking forward to that upgrade. I'll be eagerly following your build!

 

Thanks guys! Of course ive always dreamed of building a mk4 but i dont see that happening as i dont come from alot of $$ so it seems so far out of reach. So is300 it is!

Update**
Bought a new block because i needed another head. The original head had "core shift" and wouldnt be good to use for this project although it was ok for stock. Currently waiting for guide removal from machine shop, then back off to the port job again.

Will keep you posted.

Ps. Nitrous has entered the menu to spool turbo early , added it to custom harness. Tweakd and joel grannas advised parts to be shipped this week.

 

A little update *

 

 

 

The first head had a crack due to core shift so , had to get another one with a street port

I am only pending exhaust, charge pipe , and installing the fuel setup to get it running.

Still need to wire the traction control and some other goodies but its moving along .

 

@g0tgot give us an update! Anything new with this build? I've previously owned an IS300 with the intent of making it a daily driver, but ultimately had too nice of an example and didn't wanna tear it up. So she sat in the garage a lot, until I got the harebrained idea to sell, and put those funds towards the Supra I have now. I wish I could've found a way to keep the IS.

 

Hey brotha! Sorry i have been real busy and , you know how life goes i dont want to bring up anything negative but alot has been going on. Kid was sick and family members passing.. but anyway on to the positivity

Phr 4" exhaust is in place
Battery relocate is done
Working on fuel setup:
Walbro in tank -10an to check valve to Y fitting as primary. Weldon 2345a -10an out to check valve to Y fitting as secondary, -10an to fuel rail.

I also installed a chase bays power steering rez relocate, however i am having fitment issues... again.. with the gato intake.

I had to get a custom 90* bend welded to the rad dan billet upper waterneck due to the size of the radiator as a 90* an fitting was way too bulky with the PHR upper -20an water neck outlet.

I am very close to getting this thing to start but i dont want to rush it.

To do list:
Figure out wheel specs using a +50mm don musk widebody kit

Big break setup
Fill with fluid
Figs rear mega traction kit
Paint
Hood (cf)
Fab downpipe (4" from pte8385)
Fab charge pipe (90mm all the way)

We will see , i have a huge tax return coming from all the overtime i have been working this year. Things are lining up!

 

I have learned you can , with care , take a heat gun to the black plastics under the hood and get them hot and it will restore the dark black look also . In case anyone didnt know.... i didnt know and wanted to share.

 

Great build and good attention to detail.

Question: What are these white bars protecting, if any? Fuel cell?

 

Those bars are for the parachute. The mount is coming out of the bumper. Its primered to prevent rust and now i actually put some grey on it to test the color. This weekend though i actually did a few things. I gutted that black box you see there that houses the charcoal canister. I ran the vent and evap lines to the rear bumper.

I also ran my -10an fuel line through that bla k boc and into the trunk where the pump and controller will be mounted .

I have had great difficulty with the gato performance eace manifold.

#1 it is big, doesnt have a clean run for AC or throttle cable.

#2 it doesnt allow for a clean fuel run to the rear of the rail as it sits within 2 to 3 inches of the firewall

#3 i have to fight to install it where it meets the GE upper water neck on the driverside. I cant install the manifold with the water neck there.. its gotta go in first, loosely, then install waterneck, then tighten down intake because the clearances are so tight its gotta fit just right.

I have everything about 90% back together. I still need to install check valves, a Y fitting and fuel pressure regulator and filters. I am getting this reaady to tap the gas tank with a -12an to feed my secondary pump.


Will update again, will try to install BTI 7" dash next weekend.

 

Update *



Sorry for late reply.... life, work , trying to make money for car parts... new 67 gto added to familys car collection with a built 400ho and tremec 5 speed on a ford 9" .



Currently hot side and cold side getting fabbed up, car runs and has a decent basemap. Bti guage is cool gets the job done. I have gone external IACV due to no iacv port on the gato performance billet manifold.

Went to march meet at famoso raceway in bakersfield ca, ran nitro and NE1 class (alcahol 7.5 index) ..

The nitro car was on point for a 5.6 pass during qualifying however we had some rain during eliminations and it couldnt get any traction.

The 7.5 drag went 8.2 in qualifying, we had our first match bail and progressed to the next round. We made it to top 6 and then found a fuel leak and the other car went a perfect 7.50 at 258mph so we headed home..

Looking to be street tuning here in a couple of weeks hopefully and may even make it out to racewars at sonoma raceway. The car is currently FUGLY but i will get her painted eventually.

Looking into future upgrades.
Big break kit for front.

Throwing around the idea of a drysump

throwing around the idea of a gear stack for the t56 magnum F (ppg or something else after it breaks not sure)

 

 

 

Lil late on the updates. We are now on the road at 20lbs of boost. Breakin in the engine and trans and everything at the moment. Taking my time not to rush things.

Figs mega rear grip kit
Fuel cell
2 walbro 450 e85 pumps (one lift one feed)
1 weldon 2345a secondary pump

Next on the agenda is to get the car corner balanced and set to a 60/40 rear baised weight setup.

Then wrap the car gloss black