Dyno Results e34 540 vs e30 4.0 v8 same engine

[GB / John]

I just had my e30 4.0 v8 on the dyno, to see what power its putting out. Then compare the results to when the engine and gearbox was in the e34 540 as I also put that on the same dyno 8 months ago. Here are the results:-

e30 4.0 v8 - 284.4 BHP - 298 ftlb torque
e34 540 - 301 BHP - 290 ftlb torque

No doubt using the e34 540 manifolds and modifying them to fit the e30, has created more of a restriction resulting in a 16.7 BHP loss, but a gain of 8 ftlb torque.

As the e30 is a drift car, the increase in torque is a good thing, and loss in bhp don't really matter. What are your thoughts on this?

Also would it matter what gear it was done in? e30 was done in 3rd, and e34 in 4th.


Here are the graphs:-

E30 4.0 v8 M60B40


e34 540

[P Arkus]

Is the engine stock or modified? Reason I ask is because based on Wikipedia, an M60 engine is 282HP and 295TQ stock. Your WHP numbers are higher which is quite impressive!

[bmk]

Damn look at the area under the curve. V8's rock, I'm so use to looking at big turbo 4 cylinders.

[GB / John]

Its had a chip fitted for both graphs, chip gives 15-20 bhp I think.

Still not bad for a engine with 190k miles on it.

[george graves]

damn look at the area under the curve.

:d

[digger]

what wheels and tyres? this also affects results

[GB / John]

what wheels and tyres? this also affects results

e34 would be 225/50/16, and e30 was 225/45/17.

[frankenbeemer]

Is the accuracy of the dyno better than + or - 5%?

[GB / John]

Is the accuracy of the dyno better than + or - 5%?

No idea, don't know anything about Dyno's. Had fwd cars on first, then I was the first of the RWD cars.

[JGood]

It's in shootout mode, so it's estimated BHP, not WHP. Not a big deal in this comparison since both were done that way, it's just not useful to compare to any other dyno or factory numbers.

That would be about 250whp in the e34 and 230whp in the e30. Something is definitely choking that engine! Are your headers really that restrictive? I guess there's not much room on the RHD cars.

[GB / John]

Yep manifolds will be more restrictive, but would a restriction lower bhp but increase torque?





I could go tubular manifolds 4 into 1 etc, which would increase bhp but lower torque.
So a bit puzzled as to which is best.

[e30_302]

Torque "peak" may have been higher but look at the rest of the curve, which admittedly would be easier to see if the graphs used the same RPM points.

[GB / John]

I've looked at it, torque is more on e30 on lower revs, but drops off earlier after 5,200 revs.
Whats potentially better, 285bhp - 298 ftlbs torque as it is now, or go 4 into 1 manifolds which would possibly end up being around 305bhp 290 ftlbs torque?

[JGood]

I don't think you're going to lose mid range power by going to a properly designed tubular manifold. I'm really surprised you gained any mid range power by modifying them the way you did (no offense), it's not like they are designed specifically for low end torque with small primaries, etc... They are just sort of hacked up and made to fit (again, no offense... my manifolds aren't works of art either... we do what we have to do haha).

Also, that 8 lbs ft is an estimated crank number, not what you're actually putting down to the wheels. 8 x 20% = 1.6, so you're talking about ~6.5 ft lbs at the wheels. That's within the margin of error of a dyno, especially taken months apart, in different conditions, etc... Hell, I put a stock 87 325is on the dyno, and did 3 back to back runs in 5 minutes. They were as much as 5whp/trq off from each other, and that was at a low 145whp. That's like a 3.5% margin of error. 3.5% at 300hp is like 10hp. You may not have gained any mid range power at all.

You did definitely lose power up top, and that's probably due to the lack of flow in those manifolds. Going to a proper set of headers with appropriate sized primaries and collectors will absolutely help the powerband, probably from idle to redline. Just my opinion.