1989 5.0 swap into a bmw M3 trying to hit a hp target

[arphole]

As the title says I'm swapping a 1989 5.0 and t5 into a 1995 M3. I'm building the car as a road racer in NASA pt. Because it's an engine swap, I will be classed by dyno so the national director is going to give me a whp bogey for my expected weight. I'm guessing my max HP is going to be about 250 to the wheels. I know it will be less that 270 to the wheels as that is the max allowable in the class for my weight.

So, Whats the cheapest way to get that 90k 5.0 to 250 wheel hp? Emissions and low end power are not really a concern as this will be a track only. I already have shorty headers and will have to fab up custom exhaust which can be fairly wide open.

There isn't really a point in going higher as I will either end up having take on ballast or putting a restriction on the engine to bring the power down.

I'd love to do aluminum heads to bring the weight down but they are pricey so they may be out for now.

I will also be hitting you guys up for guidance during the install especially with the wiring.

Thanks
This will go

into this

 

[stykthyn]

Explorer top end will get you damn close

 

[arphole]

So and explorer intake, throttle body and heads should get me close. Do I need to do anything with the Maf? or fueling?

I really want to get close to the target. So if this setup would place me just under 250 what else could I add to get there? A cam? Roller rockers?

I like the idea of a carb and gt40 heads as it saves weight and wiring but i'm not sure it's worth the hit in fuel consumption.

 

[stykthyn]

Nope should be plug and play, a custom cam will with those parts will nail you 250 on the head and put the rpm range exactly where you need it.

 

[Mustang5L5]

To be honest, the explorer stuff might be all you need. Leave the stock cam, do the gt40p heads and explorer intake and you would prob be right at 250 rwhp or pretty damn close...especially of you are running minimum accessories.

There are guys here in the 280-300 rwhp range with junkyard explorer stuff and some additional mods, but it seems that most guys who just do heads intake are in the 240-260 rwhp range.

 

[arphole]

the thing that scares me about the gt40p heads is that I have to run two passenger side shorty headers to make this swap work (one facing froward) and I have no idea what headers will work with the p heads let alone fit on backwards. It could get pricey if I have to figure it out guess and check style.

 

[stykthyn]

Use gt40 heads. No special headers required.

 

[bp50]

YouTube - BMW 5.0 finished, with startup and walkaround check this BMW OUT!

 

[Mustang5L5]

Use gt40 heads. No special headers required.

+1. Use standard gt-40 heads.


Btw, ballpark range for used parts are

Explorer intake $75-125
Gt-40/gt-40p heads $200-300

Figure in a set of valve springs for $100 and maybe a cam for $150 and you can be close to your 250 rwhp goal right there.

Most 5.0s dyno in the 195-210 rwhp range with a manual in stock shape.

 

[2000xp8]

I'd look for some gt40y aluminum heads.
Back a few years, i got them brand new for $699 for the set.
Their used value can't be much more than $500 these days.
If you run the stock cam with a gt40, cobra, or gt40p intake you should be right around the 250rwhp mark, yet 50lbs lighter.

 

[arphole]

YouTube - BMW 5.0 finished, with startup and walkaround check this BMW OUT!

Yup that's the plan but gutted with a cage and weight of about 2550 lbs wet. Also there will be some flares and fat tires like below

I'm gonna go looking for parts. I'll hit you guys up with more questions one I start working the swap.

I appreciate all the help,
Rory

 

[phutch11]

If you wanted to, ahem, bend the rules...

Get a quarterhorse programmer and build a tune with severely restricted timing for your dyno check off, and another for the track.

You can wire in a switch that will allow you to switch between tunes on the fly.

Not saying that you should, but "they" do say that if you aren't cheating you aren't racing.

Good luck...

 

[arphole]

Well, I heard back from the rules guy and it looks like they will let me have 280 whp. Even better the wife decided I am allowed spend the money on alloy heads to save weight.

I've already got the explorer intake and throttle body.

Now I just have to pick out some heads and a cam.

 

[Flavadave4]

Cool project, I know the guys at New Age Hotrods quite well and was around when they built a few LSx powered E36's....great combo of style, power and handeling.

I had my stock heads ported and polished by Thumper, lower intake ported and polished by Tmoss, with a cam and a few odds and ends you can get 260 to the wheels pretty easy

 

[arphole]

Alright I just scored some used edlbrock performer heads,

so the buld so far is
Explorer intake and throttle body
Edelbrock heads heads performer heads

On a 89k stock bottom end
Would a tfs stage one cam with that combo get me to 280 whp?

Would I need a larger maf and injectors to hit that?

 

[FastDriver]

Yes, absolutely. Pushing stock injectors to that power level would require very high fuel pressures.

Here's an idea that does not break the rules, but does require spending some more coin. Build the baddest little 302 you can and get a Tweecer, EEC-tuner, quarterhorse, or just an SCT chip. Take timing out higher in the RPM band to keep you right at 280rwhp. That way you'll be making that power from say 5000-6500 RPM. With AFR165s, a Cobra intake, and a custom cam, I was making 320rwhp at 5300 RPM. With a higher revving cam, and a better intake, I can see you making 280rwhp across a very wide RPM band.

 

[michaelg10]

Great project, looking forward to seeing it built

 

[arphole]

Some progress. Got the engine built. Most of the parts are used from ebay and CL.
Explorer intake and TB (ported by tmoss)
Edlebrock heads
FMS roller rockers
Trick flow stage one cam
Stock bottom end

The beemer is almost ready for the install, I'm still stripping it a bit so it will be a week or so before I try to mount the engine.

Does anyone know of a respectable shop to rebuild a T5 in southern California?


I know I should rebuild it myself but I want to save time by having someone else do it as I have so much work to do.

 

[Chrome_Rust]

If you lived in Ohio I would do it for you.